A group of cyclic basic lipopeptide compounds, methods of making and uses thereof

Abstract

This invention relates to cyclic basic lipopeptide compounds, their preparation methods, and applications. The compounds described herein have the structure shown in general formula I, where AA represents an amino acid. The preparation method of the cyclic lipopeptide compounds includes the following steps: (1) reacting the free amino group of the protected basic amino acid Fmoc-AA-OP side chain with a halogenated resin to obtain Fmoc-AA-OP-resin; (2) sequentially coupling Fmoc-AA-OP-resin to obtain a linear polypeptide-resin; (3) selectively removing the protecting group from the linear polypeptide-resin and cyclizing it in a solid phase to obtain a cyclic polypeptide-resin; (4) subjecting the cyclic polypeptide-resin to acid hydrolysis and ether precipitation to obtain a crude cyclic polypeptide; (5) purifying and / or converting the crude cyclic polypeptide to salt, and then lyophilizing it to obtain a pure cyclic polypeptide. Cyclic lipopeptide compounds can be used to prepare antibacterial drugs, particularly antibacterial drugs with enhanced antibacterial activity and reduced nephrotoxicity, including antibacterial drugs against carbapenem-resistant "superbugs". R0‑CO‑AA1‑AA2‑D / L‑AA3‑ring (4‑10) [Dab4‑AA5‑D / L‑AA6‑AA7‑AA8‑AA9‑AA 10 Ⅰ.

Description

Technical Field

[0001] This invention relates to cyclic basic lipopeptide compounds and their preparation methods, as well as the use of the compound in the preparation of antibacterial drugs, particularly in the preparation of antibacterial drugs with enhanced antibacterial activity and reduced nephrotoxicity, including the use in the preparation of broad-spectrum antibacterial drugs against carbapenem-resistant "superbugs" and against Pseudomonas aeruginosa, and pharmaceutical compositions containing such compounds as active ingredients and their applications, belonging to the field of biomedicine. Background Technology

[0002] Cyclic basic lipopeptide antibiotics, polymyxins, were first reported in 1947. They are a series of cationic antimicrobial polypeptides produced by *Bacillus polymyxa*, exhibiting different structural types such as A, B, C, D, E, F, K, M, P, S, and T, with molecular weights around 1200 Da. The common structural feature of polymyxin antibiotics is that they consist of three parts: a cyclic heptapeptide, a linear tripeptide, and a side-chain acyl group linked to the linear tripeptide. They have similar antimicrobial spectra, exerting their bactericidal effect by disrupting the cell membrane of Gram-negative bacteria, leading to leakage of cell contents.

[0003] Polymyxin, a cyclic basic lipopeptide antibiotic, has been used clinically since the 1950s. However, it has a narrow antibacterial spectrum, effective only against Gram-negative bacteria, and exhibits some nephrotoxicity. Its clinical use gradually declined, especially with the emergence of new broad-spectrum antibiotics such as third-generation cephalosporins and carbapenems. In recent years, with the continuous emergence of multidrug-resistant Gram-negative bacteria, particularly carbapenem-resistant Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, polymyxin has become the last line of defense in treating carbapenem-resistant Gram-negative bacterial infections, thus regaining clinical attention.

[0004] Currently, polymyxin B and colistin (polymyxin E) are used clinically, both of which are multi-component mixtures obtained through bacterial fermentation. The polymyxins currently used clinically have complex compositions and exhibit severe nephrotoxicity, limiting their clinical application. Therefore, the design and synthesis of cyclic antimicrobial lipopeptides with high antibacterial activity and low nephrotoxicity is particularly urgent.

[0005] The chemical preparation methods of polymyxin B reported in the literature include solid-phase condensation and liquid-phase cyclization strategies. Liquid-phase cyclization requires a large amount of solvent, and the product is difficult to separate and purify, with a yield of less than 20%. In actual synthesis, the yield is even lower. The literature (deVisser PC, Kriek NM, van Hooft PA, et al. Solid-phase synthesizes polymyxin B1 and analogues via a safety-catch approach. J Pept Res, 2003, 61(6):298-306) uses Kenner's safety catch method to synthesize polymyxin B1 through solid-phase condensation and solid-phase cyclization, but the overall yield is only 1.5%. The literature (Wei-Liang Xu, A-Long Cui, Xin-Xin Hu, et al. A new strategy for total solid-phase synthesis of polymyxins. Tetrahedron Letters, 2015, 56(33):4796-4799.) uses solid-phase condensation and solid-phase cyclization to synthesize polymyxin B2 and E2, with a yield of about 25%. WO2013156977A1 ​​reports a method for solid-phase synthesis of insulin by linking lysine side-chain amino groups to a resin. This invention uses a protected basic amino acid, Fmoc-AA-OP, with a side-chain amino group similar to lysine to link to a resin, and employs solid-phase condensation and solid-phase cyclization methods to synthesize polymyxin derivatives. This method avoids the large amount of solvent generated by liquid-phase cyclization, is environmentally friendly, produces high-purity crude polypeptides, is easy to separate and purify, and has a total yield of over 30%.

[0006] Regarding the preparation of cyclic basic lipopeptide compounds, this invention provides the first-ever preparation of novel derivatives by altering the length and volume of the side-chain acyl chain to increase or decrease its hydrophobicity (changing RO-CO-), novel derivatives by replacing amino acids at positions 1 and / or 3 and / or 5 and / or 8 and / or 9 with basic or polar amino acids (changing AA1, AA3, AA5, AA8, AA9), novel derivatives by replacing amino acids at positions 6 and / or 7 with hydrophobic or polar amino acids (changing AA6, AA7), and derivatives by introducing strongly polar groups such as sulfomethyl groups into amino acid residues at positions 1, 2, 3, 5, 6, 7, 8, 9, and 10. By altering the basic amino acids or hydrophobicity of the polymyxin molecule, antibacterial activity is improved and nephrotoxicity is reduced.

[0007] Regarding the biological functions of cyclic lipopeptide derivatives, this invention investigated their antibacterial activity and nephrotoxicity. Compared with the positive control, some cyclic lipopeptide derivatives showed increased antibacterial activity against Gram-negative bacteria and decreased nephrotoxicity. In particular, the invented compounds showed improved antibacterial activity against Gram-negative bacteria, including Pseudomonas aeruginosa. - The bacteria have broad-spectrum antibacterial activity. Summary of the Invention

[0008] The purpose of this invention is to provide cyclic basic lipopeptide compounds and methods for their preparation, particularly methods for preparing cyclic lipopeptide compounds by solid-phase condensation and solid-phase cyclization. The compounds of this invention exhibit significant antibacterial effects, especially in antibacterial agents against carbapenem-resistant "superbugs."

[0009] To achieve the above objectives, the present invention employs the following technical solution:

[0010] This invention provides polymyxin compounds or pharmaceutically acceptable salts thereof, with structures as shown in general formula I:

[0011] R0-CO-AA1-AA2-D / L-AA3-ring(4-10)[Dab4-AA5-D / L-AA6-AA7-AA8-AA9-AA 10 ]

[0012] Ⅰ

[0013] Specifically, the present invention provides polymyxin compounds or pharmaceutically acceptable salts thereof according to the following embodiments.

[0014] A cyclic basic lipopeptide compound having the structure shown in Formula I, or a pharmaceutically acceptable salt thereof, wherein the compound comprises three parts: a cyclic heptapeptide, a linear tripeptide, and a side-chain acyl chain (i.e., RO-CO-) connected to the linear tripeptide, where AA represents an amino acid, wherein the carboxyl group of RO-COOH condenses with the α-amino group of AA1 to form an amide bond, the carboxyl group of AA1 condenses with the α-amino group of AA2 to form an amide bond, the carboxyl group of AA2 condenses with the α-amino group of AA3 to form an amide bond, the carboxyl group of AA3 condenses with the α-amino group of Dab4 to form an amide bond, the carboxyl group of Dab4 condenses with the α-amino group of AA5 to form an amide bond, the carboxyl group of AA5 condenses with the α-amino group of AA6 to form an amide bond, the carboxyl group of AA6 condenses with the α-amino group of AA7 to form an amide bond, the carboxyl group of AA7 condenses with the α-amino group of AA8 to form an amide bond, the carboxyl group of AA8 condenses with the α-amino group of AA9 to form an amide bond, and the carboxyl group of AA9 condenses with the α-amino group of AA8 to form an amide bond, and the carboxyl group of AA9 condenses with the α-amino group of AA9 to form an amide bond. 10 The α-amino group condenses to form an amide bond, AA 10 The carboxyl group of the compound condenses with the γ-amino group of Dab4 to form an amide bond.

[0015] R0-CO-AA1-AA2-D / L-AA3-ring(4-10)[Dab4-AA5-D / L-AA6-AA7-AA8-AA9-AA 10 ]

[0016] Ⅰ

[0017] In the formula:

[0018] R0 is selected from the following groups: (C6-C) 11 )- Straight-chain alkyl, (C7-C 12 )-branched alkyl;

[0019] AA1 and AA3 are independently selected from the following groups: Ser (serine), Ser(CH2SO3H) (2-amino-3-sulfonylmethoxypropionic acid), Dap (2,3-diaminopropionic acid), Dap(CH2SO3H) (2-amino-3-sulfonylmethoxypropionic acid), Dab (2,4-diaminobutyric acid), Dab(CH2SO3H) (2-amino-4-sulfonylmethoxybutyric acid), Orn (ornithine), Lys (lysine); the amino acid at position 1 has an L-configuration and the amino acid at position 3 has a D or L-configuration.

[0020] AA2 and AA 10 The following groups are selected independently: Thr (threonine), Thr (CH2SO3H) (2-amino-3-sulfonoxybutyric acid); the amino acids at positions 2 and 10 have an L-configuration.

[0021] Dab4 has an L-shaped configuration;

[0022] AA5, AA8, and AA9 are independently selected from the following groups: Dap (2,3-diaminopropionic acid), Dap(CH2SO3H) (2-amino-3-sulfonamide propionic acid), Dab (2,4-diaminobutyric acid), Dab(CH2SO3H) (2-amino-4-sulfonamide butyric acid), and Orn (ornithine); the amino acids at positions 5, 8, and 9 have an L-configuration.

[0023] AA6 and AA7 are independently selected from the following groups: Phe (phenylalanine), Phe(4-CH2SO3)(4-sulfomethylphenylalanine), Leu (leucine), Thr (threonine), Thr(CH2SO3H)(2-amino-3-sulfomethoxybutyric acid); the amino acid at position 6 has a D or L configuration, and the amino acid at position 7 has an L configuration.

[0024] The straight-chain alkyl group can be hexyl, heptyl, octyl, or nonyl; the branched alkyl group can be 5-methylhexyl, 5-methylheptyl, 6-methylheptyl, 6-methyloctyl, for example (S)-5-methylheptyl.

[0025] Specifically, in this invention, the antimicrobial lipopeptide compound is selected from the following compounds 1 to 120:

[0026] (1)(S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0027] (2) 6-Methylheptanyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0028] (3) Octanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0029] (4) Heptanyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0030] (5) Nonanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0031] (6)(S)-6-methyloctanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0032] (7) 6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0033] (8) Octanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0034] (9) Heptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0035] (10) Nonanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0036] (11)(S)-6-methyloctanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0037] (12)6-Methylheptanyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0038] (13) Octanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0039] (14) Heptanyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0040] (15) Nonanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0041] (16)(S)-6-methyloctanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0042] (17)6-Methylheptanyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0043] (18) Octanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0044] (19) Heptanyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0045] (20) Nonanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0046] (21)(S)-6-methyloctanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0047] (22)6-Methylheptanyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0048] (23) Octanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0049] (24) Heptanyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0050] (25) Nonanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0051] (26)(S)-6-methyloctanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0052] (27)6-Methylheptanyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0053] (28) Octanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0054] (29) Heptanyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0055] (30) Nonanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0056] (31)(S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0057] (32)6-Methylheptanyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0058] (33) Octanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0059] (34) Heptanyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0060] (35) Nonanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0061] (36)(S)-6-methyloctanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0062] (37)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0063] (38) Octanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0064] (39) Heptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0065] (40) Nonanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0066] (41)(S)-6-methyloctanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0067] (42)6-Methylheptanyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0068] (43) Octanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0069] (44) Heptanyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0070] (45) Nonanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0071] (46)(S)-6-methyloctanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0072] (47)6-Methylheptanyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0073] (48) Octanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0074] (49) Heptayl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0075] (50) Nonanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0076] (51)(S)-6-methyloctanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0077] (52)6-Methylheptanyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0078] (53) Octanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0079] (54) Heptayl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0080] (55) Nonanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0081] (56)(S)-6-methyloctanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0082] (57)6-Methylheptanyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0083] (58) Octanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0084] (59) Heptanyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0085] (60) Nonanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0086] (61)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr]

[0087] (62)6-Methylheptayl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr]

[0088] (63) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr]

[0089] (64) Heptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr]

[0090] (65) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr]

[0091] (66)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr]

[0092] (67)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr]

[0093] (68) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr]

[0094] (69) Heptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr]

[0095] (70) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr]

[0096] (71)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr]

[0097] (72)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr]

[0098] (73) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr]

[0099] (74) Heptayl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr]

[0100] (75) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr]

[0101] (76)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr]

[0102] (77)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr]

[0103] (78) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr]

[0104] (79) Heptayl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr]

[0105] (80) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr]

[0106] (81)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr]

[0107] (82)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr]

[0108] (83) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr]

[0109] (84) Heptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr]

[0110] (85) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr]

[0111] (86)(S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr]

[0112] (87)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr]

[0113] (88) Octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr]

[0114] (89) Heptayl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr]

[0115] (90) Nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr]

[0116] (91)(S)-6-methyloctanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0117] (92)6-Methylheptanyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0118] (93) Octanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0119] (94) Heptayl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0120] (95) Nonanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr]

[0121] (96)(S)-6-methyloctanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr]

[0122] (97)6-Methylheptanyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr]

[0123] (98) Octanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr]

[0124] (99) Heptayl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr]

[0125] (100) Nonanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr]

[0126] (101)(S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-Phe-Thr-Dab-Dab-Thr]

[0127] (102)6-Methylheptanyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-Phe-Thr-Dab-Dab-Thr]

[0128] (103)6-Methylheptanyl-Dab-Thr-D-Ser(CH2SO3H)-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0129] (104)6-Methylheptanyl-Dab-Thr(CH2SO3H)-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0130] (105)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr(CH2SO3H)-Dab-Dab-Thr]

[0131] (106)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr(CH2SO3H)]

[0132] (107)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe(4-CH2SO3H)-Thr-Dab-Dab-Thr]

[0133] (108)6-Methylheptanyl-Dab(CH2SO3H)-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0134] (109)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab(CH2SO3H)-D-Phe-Thr-Dab-Dab-Thr]

[0135] (110)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab(CH2SO3H)-Dab-Thr]

[0136] (111)6-Methylheptanyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab(CH2SO3H)-Thr]

[0137] (112)6-Methylheptanyl-Dab-Thr-Dap(CH2SO3H)-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0138] (113)6-Methylheptanyl-Dab-Thr(CH2SO3H)-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0139] (114)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr(CH2SO3H)-Dab-Dab-Thr]

[0140] (115)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr(CH2SO3H)]

[0141] (116)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe(4-CH2SO3H)-Thr-Dab-Dab-Thr]

[0142] (117)6-Methylheptanyl-Dab(CH2SO3H)-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]

[0143] (118)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab(CH2SO3H)-D-Phe-Thr-Dab-Dab-Thr]

[0144] (119)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab(CH2SO3H)-Dab-Thr]

[0145] (120)6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab(CH2SO3H)-Thr].

[0146] The term "ring (4-10)" refers to the heptapeptide ring formed by linking the carboxyl group of the 10th amino acid to the side chain amino group of the 4th basic amino acid via an amide bond, as shown in general formula I.

[0147] In this context, the configuration of D-amino acids is represented by D. When the configuration is not specified, it can be understood that the amino acid configuration is L. Dab represents 2,4-diaminobutyric acid, Orn represents 2,5-diaminovaleric acid, and Dap represents 2,3-diaminopropionic acid.

[0148] The cyclic basic lipopeptide compound or its pharmaceutically acceptable salt according to the present invention, wherein the pharmaceutically acceptable salt of the compound of general formula I comprises a salt formed by the compound of general formula I and an acid, wherein the acid is selected from the group consisting of: inorganic acids or organic acids, wherein the inorganic acid is preferably perchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid; and the organic acid is preferably acetic acid, trifluoroacetic acid, lactic acid, succinic acid, fumaric acid, maleic acid, citric acid, benzoic acid, methanesulfonic acid or p-toluenesulfonic acid.

[0149] This invention also provides a method for solid-phase synthesis of cyclic lipopeptide compounds or their pharmaceutically acceptable salts. This method prepares polymyxin compounds or their pharmaceutically acceptable salts through solid-phase condensation and solid-phase cyclization, comprising the following steps:

[0150] (1) The protected basic amino acid Fmoc-AA-OP side chain free amino group reacts with a halogenated resin to obtain Fmoc-AA-OP-resin; wherein P is a carboxyl protecting group, for example, allyl (Allyl) or benzyl (Bn); when Fmoc-AA-OP is Fmoc-Dab-OP, its structure is as shown in Formula II; when Fmoc-AA-OP is Fmoc-Dap-OP, its structure is as shown in Formula III; when Fmoc-AA-OP is Fmoc-Orn-OP, its structure is as shown in Formula IV.

[0151]

[0152] (2) Linear peptide-resin was obtained by sequential coupling of Fmoc-AA-OP-resin;

[0153] (3) Cyclic peptide-resin was obtained by selectively removing the protecting group from linear peptide-resin and cyclizing it in solid phase.

[0154] (4) Cyclic polypeptides are obtained by acid hydrolysis of resin;

[0155] (5) The crude cyclic polypeptide is purified and / or converted to salt, and then freeze-dried to obtain the pure cyclic polypeptide.

[0156] Regarding step (1):

[0157] The halogenated resin mentioned in step (1) is selected from: triphenylmethyl chloride resin, 4-methyltriphenylmethyl chloride resin, 4-methoxytriphenylmethyl chloride resin, 2-chlorotriphenylmethyl chloride resin, bromo-(4-methylphenyl)-methyl resin or bromo-(4-methoxyphenyl)-methyl resin, for example, the resin is one or more of 2-chlorotriphenylmethyl chloride resin.

[0158] The degree of substitution of the halogenated resin is 0.1-1.6 mmol / g, preferably 0.5-1.0 mmol / g.

[0159] The amount of each Fmoc-protected amino acid is 1.2-6 times the total molar amount of the resin fed, preferably 2.0-4.0 times.

[0160] The base is selected from at least one of N,N-diisopropylethylamine (DIEA), triethylamine (TEA), and pyridine, preferably DIEA; the molar amount of the base is 1.5-3 times the molar amount of the Fmoc-protected amino acid, preferably 2 times the molar amount of the Fmoc-protected amino acid.

[0161] The substitution reaction time is 1-12 hours, preferably 2-3 hours.

[0162] Regarding step (2):

[0163] The reagent used to remove the α-amino Fmoc protecting group in step (2) includes, but is not limited to, a solution of piperidine (PIP) in DMF with a concentration of 10-30%, preferably 20%. The amount of deprotecting reagent used is 5-15 mL per gram of resin, preferably 10 mL per gram of resin. The deprotection reaction time is 10-60 min, preferably 10-20 min. The reagent used to remove the ivDde or Dde protecting group from the 4-position amino side chain includes, but is not limited to, a solution of hydrazine hydrate in DMF with a concentration of 1-10%, preferably 2%. The amount of deprotecting reagent used is 5-15 mL per gram of resin, preferably 10 mL per gram of resin. The deprotection reaction time is 30-100 min, preferably 30-60 min.

[0164] The coupling agent in the coupling reaction is selected from at least one of the following: N,N-diisopropylcarbodiimide (DIC), N,N-dicyclohexylcarbodiimide (DCC), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate (HBTU), 6-chlorobenzotriazole-1,1,3,3-tetramethylurea hexafluorophosphate (HCTU), 2-(7-azobenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (HATU), O-benzotriazole-N,N,N',N'-tetramethylurea tetrafluoroborate (TBTU), and benzotriazole-1-yl-oxytripyrrolidinylphosphonium hexafluorophosphate (PyBOP), preferably 6-chlorobenzotriazole-1,1,3,3-tetramethylurea hexafluorophosphate (HCTU).

[0165] The molar amount of coupling agent is 1.2-6 times the total molar amount of resin fed, preferably 2.0-4.0 times.

[0166] The activator is selected from at least one of 1-hydroxybenzotriazole (HOBT), 6-chloro-1-hydroxybenzotriazole (Cl-HOBT), and 1-hydroxy-7-azobenzotriazole (HOAT), preferably 1-hydroxybenzotriazole (HOBT).

[0167] The molar amount of activator is 1.2-6 times the total molar amount of resin fed, preferably 2.0-4.0 times.

[0168] The coupling reaction time is 60-300 min, preferably 60-120 min.

[0169] In the coupling reaction, a catalyst needs to be added to some of the coupling agents. The catalyst is an organic base, selected from: N,N-diisopropylethylamine (DIEA), triethylamine (TEA), and N-methylmorpholine (NMM), preferably N,N-diisopropylethylamine (DIEA).

[0170] The solvent is an aprotic polar solvent selected from: dimethylformamide (DMF) or N-methylpyrrolidone (NMP) or mixtures thereof, preferably DMF.

[0171] Regarding step (3)

[0172] In step (3), the reagent for removing the allyl protecting group from the carboxyl group is a solution of tetrakis(triphenylphosphine)palladium / phenylsilane in DCM and DMF (a mixed solution with a DCM:DMF volume ratio of 5:5). The molar amount of tetrakis(triphenylphosphine)palladium is 0.1-2 times the total molar amount of the resin fed, preferably 0.1-0.3 times. The molar amount of phenylsilane is 2-10 times the total molar amount of the resin fed, preferably 3-7 times. The amount of deprotecting reagent used is 10-30 mL per gram of resin fed, preferably 20 mL per gram of resin fed. The deprotection reaction time is 60-300 min, preferably 60-120 min. The reagent for removing the carboxyl benzyl protecting group is H2, a 10% Pd / C ethanol solution, and the molar amount of 10% Pd / C is 0.1-2 times the total molar amount of the resin fed, preferably 0.1-0.3 times. The deprotection reaction time is 30-100 min, preferably 30-60 min.

[0173] The solid-phase cyclization coupling agent is selected from the group consisting of: (3H-1,2,3-triazol[4,5-b]pyridine-3-oxy)tri-1-pyrrolidinyl phosphonium hexafluorophosphate (PyAOP), benzotriazol-1-yl-oxytripyrrolidinyl phosphonium hexafluorophosphate (PyBOP), preferably (3H-1,2,3-triazol[4,5-b]pyridine-3-oxy)tri-1-pyrrolidinyl phosphonium hexafluorophosphate (PyAOP).

[0174] The molar amount of coupling agent is 1.2-6 times the total molar amount of resin fed, preferably 2.0-4.0 times.

[0175] The activator is selected from the group consisting of: 1-hydroxybenzotriazole (HOBT), 1-hydroxy-7-azobenzotriazole (HOAT), preferably 1-hydroxy-7-azobenzotriazole (HOAT).

[0176] The molar amount of activator is 1.2-6 times the total molar amount of resin fed, preferably 2.0-4.0 times.

[0177] The cyclization reaction time is 1-20 h, preferably 1-3 h.

[0178] The catalyst is an organic base, selected from the group consisting of: N,N-diisopropylethylamine (DIEA), triethylamine (TEA), N-methylmorpholine (NMM), preferably N-methylmorpholine (NMM).

[0179] The solvent is an aprotic polar solvent, selected from the group consisting of dimethylformamide (DMF) or N-methylpyrrolidone (NMP) or mixtures thereof, preferably DMF.

[0180] Regarding step (4):

[0181] In step (4), the acid hydrolysis solution contains hydrofluoric acid (HF) or trifluoroacetic acid (TFA), preferably trifluoroacetic acid.

[0182] The amount of acid hydrolysate used is 5-30 mL per gram of resin, preferably 10 mL per gram of resin. The acid hydrolysate contains trifluoroacetic acid and a side-chain protecting group remover.

[0183] The trifluoroacetic acid concentration is 80%-95%, and the remainder is a side-chain protecting group remover.

[0184] The side-chain protecting group remover is selected from the group consisting of: anisole, triisopropylsilane, phenol, water, 1,2-ethylenedithiol, preferably water.

[0185] The acid hydrolysis time is 60-300 min, preferably 100-120 min.

[0186] The acid hydrolysate containing peptides was added to cold diethyl ether (the volume ratio of acid hydrolysate to cold diethyl ether was 1:20) to precipitate peptides. The peptides were then centrifuged and dried to obtain crude peptides.

[0187] Regarding step (5):

[0188] In step (5), the crude peptide is dissolved in water, filtered through a 0.22 μm pore size filter membrane, and purified by preparative high-performance liquid chromatography (HPLC). Gradient elution is performed using mobile phase A (0.1% TFA / water solution) and mobile phase B (0.1% TFA / acetonitrile solution). The detection wavelength is 214 nm. The product is then lyophilized. The final purity achievable by this method is greater than 95%, preferably greater than 99%.

[0189] Specifically, the preparation method of the present invention includes the following steps:

[0190] In step (1), the preparation of Fmoc-AA-OP-resin is carried out as follows: the halogenated resin is added to the polypeptide solid-phase synthesis tube, DCM is added to swell, after swelling is completed, it is washed three times with DMF and three times with DCM, the protected starting amino acids Fmoc-AA-OP and DIEA are dissolved in DCM and added to the polypeptide synthesis tube, reacted at room temperature for 2 hours, the reaction solution is removed by vacuum, the resin is washed three times with DMF and three times with DCM to obtain Fmoc-AA-OP-resin.

[0191] In step (2), the coupling synthesis method includes: the Fmoc-AA-OP-resin obtained in step (1) is treated with 20% piperidine / DMF (twice, 10 min each time) to remove the α-amino Fmoc protecting group, washed three times with DMF and three times with DCM, the amino acid or side chain carboxylic acid (RO-COOH), HCTU and HOBT are dissolved in DMF and added to the polypeptide synthesis tube, reacted at room temperature for 120 min, the reaction solution is removed by vacuum, washed three times with DMF and three times with DCM. The peptide-resin is prepared by coupling amino acids one by one from the 8th amino acid to the 1st amino acid, and then coupling the side-chain carboxylic acid to the protected peptide-resin. The ivDde or Dde protecting group of the 4th amino acid side chain amino group is removed with 2% hydrazine hydrate / DMF solution (30 min), followed by washing three times with DMF and three times with DCM. The carboxyl group of the 10th amino acid is then coupled to the 4th amino acid side chain amino group to obtain a linear, fully protected peptide-resin. Alternatively, the peptide-resin is prepared by coupling amino acids one by one from the 7th amino acid to the 1st amino acid, and then coupling the side-chain carboxylic acid to the protected peptide-resin. The ivDde or Dde protecting group of the 4th amino acid side chain amino group is removed with 2% hydrazine hydrate / DMF solution, followed by washing three times with DMF and three times with DCM. The carboxyl group of the 10th amino acid is then coupled to the 4th amino acid side chain amino group, and the carboxyl group of the 9th amino acid is then coupled to the 10th amino acid α-amino group to obtain a linear, fully protected peptide-resin.

[0192] In step (3), the specific method for selectively removing the protecting group and solid-phase cyclization is as follows: The linear fully protected peptide-resin from step (2) is treated with 20% piperidine / DMF (twice, 10 min each time) to remove the α-amino Fmoc protecting group, washed three times with DMF and three times with DCM to form a free amino group; the carboxyl allyl protecting group is removed with a solution of tetrakis(triphenylphosphine)palladium / phenylsilane in DCM and DMF (a mixed solution of DCM:DMF with a volume ratio of 5:5) (120 min) to form a free carboxyl group. PyAOP and HOAT are dissolved in DMF and added to NMM, then added to the peptide synthesis tube and reacted at room temperature for 3 h. The reaction solution is removed under vacuum, washed three times with DMF and three times with DCM to obtain a cyclic fully protected peptide-resin.

[0193] In step (4), the specific method for obtaining the crude cyclic basic peptide by acid hydrolysis is as follows: the acid hydrolysis solution (TFA:H2O volume ratio of 95:5) is added to the peptide synthesis tube and reacted at room temperature for 120 min. The acid hydrolysis solution is then added to cold ether (TFA lysis solution to cold ether ratio of 1:20) to precipitate the peptide. After centrifugation and drying, the crude peptide is obtained.

[0194] In step (5), the specific methods for crude product purification, salt conversion, and freeze-drying are as follows: The crude product is dissolved in water and filtered through a 0.22 μm filter membrane for later use. It is then subjected to preparative high-performance liquid chromatography (HPLC) with a 10 μm reversed-phase C18 packing material, mobile phase A of 0.1% TFA / water solution, mobile phase B of 0.1% TFA / acetonitrile solution, a 22 mm × 250 mm column with a flow rate of 10 mL / min, and a detection wavelength of 215 nm. Gradient elution is used, and the product is purified by cyclic injection. The crude product solution is loaded into the chromatographic column, and the mobile phase is started for elution. The fractions corresponding to the main chromatographic peak are collected, and the acetonitrile is removed from the fractions to obtain an aqueous solution of polymyxin compound. The product is then freeze-dried to obtain the final product.

[0195] The final purity achievable by this method is greater than 95.0%, preferably greater than 99.0%. The yield, calculated using the resin, is greater than 30.0%.

[0196] This invention prepares novel compounds with altered basic amino acids or hydrophobicity of cyclic lipopeptide molecules. The compounds of this invention are easily prepared according to the described chemical synthesis method, while the clinically used polymyxin B and colistin (polymyxin E) are multi-component mixtures obtained by bacterial fermentation.

[0197] Table 1 shows the structures of some of the inventive compounds.

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205] Another object of the present invention is to provide the use of the cyclic basic lipopeptide compound having the structure shown in general formula I or a pharmaceutically acceptable salt thereof in the preparation of antibacterial drugs.

[0206] Among them, antibacterial refers to antibacterial agents that are effective against Gram-negative bacteria. Gram-negative bacteria include Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanii, Salmonella, Moraxella, Helicobacter, Legionella, Haemophilus influenzae, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Morganella morganii, Providentia rettgeri, Proteus vulgaris, Proteus mirabilis, and Stenotrophomonas maltophilia. ia), Citrobacter freundii, etc.

[0207] Gram-negative bacteria include Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumanii.

[0208] This invention also provides cyclic lipopeptide compounds or their pharmaceutically acceptable salts that exhibit higher antibacterial activity and lower nephrotoxicity than clinically used polymyxin B and colistin (polymyxin E). The kidney cells are selected from the group consisting of: human renal tubular epithelial cells (HK-2 cells), human embryonic renal epithelial cells (HEK293 cells), African green monkey kidney cells (Vero cells), canine kidney cells (MDCK cells), for example, human renal tubular epithelial cells (HK-2 cells).

[0209] The present invention also provides an antibacterial pharmaceutical composition comprising a therapeutically effective amount of a cyclic basic lipopeptide compound having the structure shown in general formula I or a pharmaceutically acceptable salt thereof as an active ingredient. The compound itself or a mixture thereof with pharmaceutical excipients, diluents, etc., may be administered orally in the form of tablets, capsules, granules, powders or syrups, or non-orally in the form of injections, sprays, aerosols, ointments or eye drops.

[0210] The above-mentioned formulations can be prepared using conventional pharmaceutical methods. Examples of pharmaceutical excipients and diluents that can be used include excipients (e.g., sugar derivatives such as lactose, sucrose, glucose, mannitol, and sorbitol; starch derivatives such as corn starch, potato starch, dextrin, and carboxymethyl starch; cellulose derivatives such as crystalline cellulose, hydroxypropyl cellulose, hydroxymethyl cellulose, calcium hydroxymethyl cellulose, and sodium hydroxymethyl cellulose; gum arabic; dextran; silicate derivatives such as magnesium aluminum metasilicate; phosphate derivatives such as calcium phosphate; carbonate derivatives such as calcium carbonate; sulfate derivatives such as calcium sulfate, etc.); binders (e.g., gelatin, polyvinylpyrrolidone, and polyethylene glycol); disintegrants (e.g., cellulose derivatives such as sodium carboxymethyl cellulose and polyvinylpyrrolidone); lubricants (e.g., talc, calcium stearate, magnesium stearate, cetyl, boric acid, sodium benzoate, and leucine); stabilizers (e.g., methylparaben, propylparaben, etc.); flavoring agents (e.g., commonly used sweeteners, acidulants, and flavorings); diluents and injection solvents (e.g., water, ethanol, and glycerin, etc.).

[0211] Synthetic route: Taking the synthetic route of compound 1 as an example, the other compounds are synthesized using a similar route. The reaction conditions of the other compounds are the same as those of compound 1. The difference lies in the type and order of the starting amino acid Fmoc-AA-OP and the amino acids and fatty acids added during the coupling reaction.

[0212]

[0213] P stands for Allyl.

[0214] P1 represents: tert-butyloxycarbonyl (Boc)

[0215] P2 represents: 1-(4,4-dimethyl-2,6-dioxocyclohexyl-1-yl)-ethyl (Dde), 1-(4,4-dimethyl-2,6-dioxocyclohexyl-1-yl)-3-methylbutyl (ivDde)

[0216] P3 stands for tert-butyl (tBu).

[0217] Fmoc stands for: 9-fluorenemethyloxycarbonyl

[0218] Compared with existing compounds or synthesis methods, this invention is convenient, fast, environmentally friendly, produces high-purity crude peptides that are easy to separate and purify, and has a total yield of up to 40%. Detailed Implementation

[0219] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0220] Example 1: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 1)

[0221] The order in which the protected amino acid and the side-chain carboxylic acid are added to the reaction in the synthetic route is as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0222] 0.5 mmol of 2-Cl-Trt resin (degree of substitution = 0.5 mmol / g) was added to a polypeptide solid-phase synthesis tube to prepare (S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] according to the method shown in the synthesis route.

[0223] 530 mg of crude peptide was obtained, with a yield of 90.0%. The crude peptide was dissolved in water and filtered through a 0.22 μm filter membrane for later use. It was then purified by preparative high-performance liquid chromatography (HPLC) using a 10 μm reversed-phase C18 column. The mobile phases were 0.1% TFA / water solution (A) and 0.1% TFA / acetonitrile solution (B). A 22 mm × 250 mm column was used, with a mobile phase flow rate of 8 mL / min and a detection wavelength of 214 nm. Gradient elution was employed, and the sample was purified by cyclic injection. The crude solution was loaded onto the column, and elution was initiated. The fraction corresponding to the main chromatographic peak was collected and the acetonitrile was removed by evaporation to obtain an aqueous solution of compound 1. The product was then freeze-dried.

[0224] The yield was 238 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). +).

[0225] Example 2: Preparation of 6-methylheptanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 2)

[0226] Compound 2 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0227] The yield was 240 mg, representing a yield of 41.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0228] Example 3: Preparation of octanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 3)

[0229] Compound 3 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0230] The yield was 235 mg, representing a yield of 40.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0231] Example 4: Preparation of heptayl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 4)

[0232] Compound 4 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0233] The yield was 230 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1149.7 ([M+H)). + ).

[0234] Example 5: Preparation of nonanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 5)

[0235] Compound 5 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0236] The yield was 250 mg, representing a yield of 42.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0237] Example 6: Preparation of (S)-6-methyloctanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 6)

[0238] Compound 6 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0239] The yield was 240 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0240] Example 7: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 7)

[0241] Compound 7 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0242] The yield was 242 mg, representing a yield of 41.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0243] Example 8: Preparation of octanoyl-Dab-Thr-Dap-ring (4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 8)

[0244] Compound 8 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0245] The yield was 238 mg, representing a yield of 40.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0246] Example 9: Preparation of heptayl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 9)

[0247] Compound 9 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0248] The yield was 235 mg, representing a yield of 40.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1149.7 ([M+H)). + ).

[0249] Example 10: Preparation of nonanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 10)

[0250] Compound 10 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0251] The yield was 251 mg, representing a yield of 42.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0252] Example 11: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 11)

[0253] Compound 11 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0254] The yield was 248 mg, representing a yield of 41.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0255] Example 12: Preparation of 6-methylheptanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 12)

[0256] Compound 12 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0257] The yield was 240 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0258] Example 13: Preparation of octanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 13)

[0259] Compound 13 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0260] The yield was 235 mg, representing a yield of 39.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0261] Example 14: Preparation of heptayl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 14)

[0262] Compound 14 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, Fmoc-Thr(tBu)-OH.

[0263] The yield was 235 mg, representing a yield of 40.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0264] Example 15: Preparation of nonanoyl-Dab-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 15)

[0265] Compound 15 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0266] The yield was 250 mg, representing a yield of 42.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0267] Example 16: Preparation of (S)-6-methyloctanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 16)

[0268] Compound 16 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0269] The yield was 245 mg, representing a yield of 41.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0270] Example 17: Preparation of 6-methylheptanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 17)

[0271] Compound 17 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0272] The yield was 245 mg, representing a yield of 41.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0273] Example 18: Preparation of octanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 18)

[0274] Compound 18 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0275] The yield was 241 mg, representing a yield of 40.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0276] Example 19: Preparation of heptayl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 19)

[0277] Compound 19 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, Fmoc-Thr(tBu)-OH.

[0278] The yield was 238 mg, representing a yield of 40.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0279] Example 20: Preparation of nonanoyl-Dab-Thr-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 20)

[0280] Compound 20 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0281] The yield was 254 mg, representing a yield of 42.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0282] Example 21: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 21)

[0283] Compound 21 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0284] The yield was 251 mg, representing a yield of 41.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1205.7 ([M+H)). + ).

[0285] Example 22: Preparation of 6-methylheptanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 22)

[0286] Compound 22 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0287] The yield was 243 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0288] Example 23: Preparation of octanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 23)

[0289] Compound 23 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0290] The yield was 239 mg, representing a yield of 40.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0291] Example 24: Preparation of heptanyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 24)

[0292] Compound 24 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0293] The yield was 238 mg, representing a yield of 40.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0294] Example 25: Preparation of nonanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 25)

[0295] Compound 25 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0296] The yield was 253 mg, representing a yield of 42.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1205.7 ([M+H)). + ).

[0297] Example 26: Preparation of (S)-6-methyloctanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 26)

[0298] Compound 26 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0299] The yield was 248 mg, representing a yield of 41.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1205.7 ([M+H)). + ).

[0300] Example 27: Preparation of 6-methylheptanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 27)

[0301] Compound 27 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0302] The yield was 245 mg, representing a yield of 41.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0303] Example 28: Preparation of octanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 28)

[0304] Compound 28 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0305] The yield was 244 mg, representing a yield of 40.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1191.7 ([M+H)). + ).

[0306] Example 29: Preparation of heptayl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 29)

[0307] Compound 29 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0308] The yield was 240 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0309] Example 30: Preparation of nonanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 30)

[0310] Compound 30 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0311] The yield was 258 mg, representing a yield of 42.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1205.7 ([M+H)). + ).

[0312] Example 31: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 31)

[0313] Compound 31 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0314] The yield was 241 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0315] Example 32: Preparation of 6-methylheptanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 32)

[0316] Compound 32 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0317] The yield was 245 mg, representing a yield of 41.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0318] Example 33: Preparation of octanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 33)

[0319] Compound 33 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0320] The yield was 238 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0321] Example 34: Preparation of heptayl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 34)

[0322] Compound 34 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0323] The yield was 235 mg, representing a yield of 40.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1161.7 ([M+H)). + ).

[0324] Example 35: Preparation of nonanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 35)

[0325] Compound 35 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0326] The yield was 254 mg, representing a yield of 42.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0327] Example 36: Preparation of (S)-6-methyloctanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 36)

[0328] Compound 36 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0329] The yield was 245 mg, representing a yield of 41.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0330] Example 37: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 37)

[0331] Compound 37 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0332] The yield was 245 mg, representing a yield of 41.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0333] Example 38: Preparation of octanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 38)

[0334] Compound 38 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0335] The yield was 235 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0336] Example 39: Preparation of heptayl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 39)

[0337] Compound 39 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0338] The yield was 235 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1161.7 ([M+H)). + ).

[0339] Example 40: Preparation of nonanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 40)

[0340] Compound 40 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0341] The yield was 250 mg, representing a yield of 42.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0342] Example 41: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 41)

[0343] Compound 41 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0344] The yield was 254 mg, representing a yield of 41.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1217.7 ([M+H)). + ).

[0345] Example 42: Preparation of 6-methylheptanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 42)

[0346] Compound 42 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0347] The yield was 245 mg, representing a yield of 40.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1203.7 ([M+H)). + ).

[0348] Example 43: Preparation of octanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 43)

[0349] Compound 43 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0350] The yield was 244 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1203.7 ([M+H)). + ).

[0351] Example 44: Preparation of heptayl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 44)

[0352] Compound 44 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0353] The yield was 239 mg, representing a yield of 40.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0354] Example 45: Preparation of nonanoyl-Dab-Thr-D-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 45)

[0355] Compound 45 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0356] The yield was 255 mg, representing a yield of 41.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1205.7 ([M+H)). + ).

[0357] Example 46: Preparation of (S)-6-methyloctanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 46)

[0358] Compound 46 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0359] The yield was 248 mg, representing a yield of 40.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (by area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1217.7 ([M+H)). + ).

[0360] Example 47: Preparation of 6-methylheptanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 47)

[0361] Compound 47 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0362] The yield was 241 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1203.7 ([M+H)). + ).

[0363] Example 48: Preparation of octanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 48)

[0364] Compound 48 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, and Fmoc-Thr(tBu)-OH.

[0365] The yield was 245 mg, representing a yield of 40.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1203.7 ([M+H)). + ).

[0366] Example 49: Preparation of heptayl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (compound 49)

[0367] Compound 49 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0368] The yield was 245 mg, representing a yield of 41.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0369] Example 50: Preparation of nonanoyl-Dab-Thr-Orn-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 50)

[0370] Compound 50 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0371] The yield was 250 mg, representing a yield of 41.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1217.7 ([M+H)). + ).

[0372] Example 51: Preparation of (S)-6-methyloctanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 51)

[0373] Compound 51 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0374] The yield was 241 mg, representing a yield of 41.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0375] Example 52: Preparation of 6-methylheptanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 52)

[0376] Compound 52 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0377] The yield was 241 mg, representing a yield of 41.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0378] Example 53: Preparation of octanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 53)

[0379] Compound 53 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, octanoic acid, and Fmoc-Thr(tBu)-OH.

[0380] The yield was 235 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0381] Example 54: Preparation of heptayl-Dap-Thr-D-Ser-ring (4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 54)

[0382] Compound 54 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0383] The yield was 235 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1136.6 ([M+H)). + ).

[0384] Example 55: Preparation of nonanoyl-Dap-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 55)

[0385] Compound 55 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0386] The yield was 250 mg, representing a yield of 42.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0387] Example 56: Preparation of (S)-6-methyloctanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 56)

[0388] Compound 56 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Orn(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0389] The yield was 240 mg, which, based on the 0.5 mmol 2-Cl-Trt resin, represents a yield of 40.2%. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H]+).

[0390] Example 57: Preparation of 6-methylheptanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 57)

[0391] Compound 57 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Orn(Boc)-OH, 6-methylheptanoic acid, and Fmoc-Thr(tBu)-OH.

[0392] The yield was 240 mg, which, based on the 0.5 mmol 2-Cl-Trt resin, represents a yield of 40.7%. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H]+).

[0393] Example 58: Preparation of octanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 58)

[0394] Compound 58 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Orn(Boc)-OH, octanoic acid, and Fmoc-Thr(tBu)-OH.

[0395] The yield was 240 mg, which, based on the 0.5 mmol 2-Cl-Trt resin, represents a yield of 40.7%. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H]+).

[0396] Example 59: Preparation of heptayl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (compound 59)

[0397] Compound 59 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Orn(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0398] The yield was 238 mg, which, based on the 0.5 mmol 2-Cl-Trt resin, represents a yield of 40.9%. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H]+).

[0399] Example 60: Preparation of nonanoyl-Orn-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 60)

[0400] Compound 60 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Orn(Boc)-OH, nonanoic acid, and Fmoc-Thr(tBu)-OH.

[0401] The yield was 252 mg, which, based on the 0.5 mmol 2-Cl-Trt resin, represents a yield of 42.3%. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H]+).

[0402] Example 61: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr] (Compound 61)

[0403] Compound 61 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dap(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0404] The yield was 241 mg, representing a yield of 41.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0405] Example 62: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr] (Compound 62)

[0406] Compound 62 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dap(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0407] The yield was 240 mg, representing a yield of 41.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0408] Example 63: Preparation of octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr] (compound 63)

[0409] Compound 63 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dap(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0410] The yield was 230 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0411] Example 64: Preparation of heptayl-Dab-Thr-D-Ser-ring (4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr] (compound 64)

[0412] Compound 64 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dap(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0413] The yield was 230 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1136.6 ([M+H)). + ).

[0414] Example 65: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dap-D-Phe-Thr-Dab-Dab-Thr] (Compound 65)

[0415] Compound 65 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dap(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0416] The yield was 250 mg, representing a yield of 42.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0417] Example 66: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr] (Compound 66)

[0418] Compound 66 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Orn(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0419] The yield was 240 mg, representing a yield of 40.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0420] Example 67: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr] (Compound 67)

[0421] Compound 67 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Orn(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0422] The yield was 245 mg, representing a yield of 41.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0423] Example 68: Preparation of octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr] (Compound 68)

[0424] Compound 68 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Orn(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0425] The yield was 236 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0426] Example 69: Preparation of heptanyl-Dab-Thr-D-Ser-ring (4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr] (compound 69)

[0427] Compound 69 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Orn(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0428] The yield was 235 mg, representing a yield of 40.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0429] Example 70: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Orn-D-Phe-Thr-Dab-Dab-Thr] (Compound 70)

[0430] Compound 70 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Orn(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0431] The yield was 250 mg, representing a yield of 41.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0432] Example 71: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr] (Compound 71)

[0433] Compound 71 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0434] The yield was 240 mg, representing a yield of 41.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0435] Example 72: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr] (Compound 72)

[0436] Compound 72 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0437] The yield was 240 mg, representing a yield of 41.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0438] Example 73: Preparation of octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr] (compound 73)

[0439] Compound 73 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0440] The yield was 231 mg, representing a yield of 40.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0441] Example 74: Preparation of heptayl-Dab-Thr-D-Ser-ring (4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr] (compound 74)

[0442] Compound 74 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0443] The yield was 231 mg, representing a yield of 40.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1136.6 ([M+H)). + ).

[0444] Example 75: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dap-Dab-Thr] (Compound 75)

[0445] Compound 75 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0446] The yield was 250 mg, representing a yield of 42.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0447] Example 76: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr] (Compound 76)

[0448] Compound 76 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0449] The yield was 241 mg, representing a yield of 40.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0450] Example 77: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr] (Compound 77)

[0451] Compound 77 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0452] The yield was 246 mg, representing a yield of 41.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0453] Example 78: Preparation of octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr] (Compound 78)

[0454] Compound 78 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0455] The yield was 238 mg, representing a yield of 40.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0456] Example 79: Preparation of heptayl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr] (Compound 79)

[0457] Compound 79 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0458] The yield was 236 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0459] Example 80: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Orn-Dab-Thr] (Compound 80)

[0460] Compound 80 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Orn(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0461] The yield was 251 mg, representing a yield of 42.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0462] Example 81: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr] (Compound 81)

[0463] Compound 81 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dap-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0464] The yield was 241 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0465] Example 82: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr] (Compound 82)

[0466] Compound 82 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dap-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0467] The yield was 240 mg, representing a yield of 41.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0468] Example 83: Preparation of octanoyl-Dab-Thr-D-Ser-ring (4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr] (Compound 83)

[0469] Compound 83 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dap-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0470] The yield was 232 mg, representing a yield of 40.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1150.6 ([M+H)). + ).

[0471] Example 84: Preparation of heptayl-Dab-Thr-D-Ser-ring (4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr] (Compound 84)

[0472] Compound 84 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dap-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0473] The yield was 231 mg, representing a yield of 40.6% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1136.6 ([M+H)). + ).

[0474] Example 85: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dap-Thr] (Compound 85)

[0475] Compound 85 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dap-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0476] The yield was 249 mg, representing a yield of 42.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0477] Example 86: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr] (Compound 86)

[0478] Compound 86 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Orn-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0479] The yield was 240 mg, representing a yield of 40.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0480] Example 87: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr] (Compound 87)

[0481] Compound 87 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Orn-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0482] The yield was 245 mg, representing a yield of 41.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0483] Example 88: Preparation of octanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr] (Compound 88)

[0484] Compound 88 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Orn-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, octanoic acid, Fmoc-Thr(tBu)-OH.

[0485] The yield was 237 mg, representing a yield of 40.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1178.7 ([M+H)). + ).

[0486] Example 89: Preparation of heptayl-Dab-Thr-D-Ser-ring (4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr] (Compound 89)

[0487] Compound 89 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Orn-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0488] The yield was 235 mg, representing a yield of 40.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1164.7 ([M+H)). + ).

[0489] Example 90: Preparation of nonanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Orn-Thr] (Compound 90)

[0490] Compound 90 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Orn-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0491] The yield was 251 mg, representing a yield of 42.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1192.7 ([M+H)). + ).

[0492] Example 91: Preparation of (S)-6-methyloctanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 91)

[0493] Compound 91 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0494] The yield was 241 mg, representing a yield of 40.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0495] Example 92: Preparation of 6-methylheptanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 92)

[0496] Compound 92 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0497] The yield was 241 mg, representing a yield of 41.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0498] Example 93: Preparation of octanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 93)

[0499] Compound 93 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, octanoic acid, and Fmoc-Thr(tBu)-OH.

[0500] The yield was 240 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1175.7 ([M+H)). + ).

[0501] Example 94: Preparation of heptayl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 94)

[0502] Compound 94 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0503] The yield was 240 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1161.7 ([M+H)). + ).

[0504] Example 95: Preparation of nonanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Phe-Leu-Dab-Dab-Thr] (Compound 95)

[0505] Compound 95 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0506] The yield was 240 mg, representing a yield of 40.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1189.7 ([M+H)). + ).

[0507] Example 96: Preparation of (S)-6-methyloctanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr] (Compound 96)

[0508] Compound 96 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Leu-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0509] The yield was 240 mg, representing a yield of 41.5% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1155.7 ([M+H)). + ).

[0510] Example 97: Preparation of 6-methylheptanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr] (Compound 97)

[0511] Compound 97 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Leu-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0512] The yield was 240 mg, representing a yield of 42.0% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1141.7 ([M+H)). + ).

[0513] Example 98: Preparation of octanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr] (Compound 98)

[0514] Compound 98 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Leu-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, octanoic acid, and Fmoc-Thr(tBu)-OH.

[0515] The yield was 241 mg, representing a yield of 42.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1141.7 ([M+H)). + ).

[0516] Example 99: Preparation of heptayl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr] (Compound 99)

[0517] Compound 99 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Leu-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, heptanoic acid, and Fmoc-Thr(tBu)-OH.

[0518] The yield was 230 mg, representing a yield of 40.8% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1127.7 ([M+H)). + ).

[0519] Example 100: Preparation of nonanoyl-Dap-Thr-D-Dab-cyclo(4-10)[Dab-Dab-D-Leu-Leu-Dab-Dab-Thr] (Compound 100)

[0520] Compound 100 was prepared under the same reaction conditions and purification method as compound 1. The order of addition of the protective amino acid and the side-chain carboxylic acid in the synthetic route was as follows: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Leu-OH, Fmoc-D-Leu-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dap(Boc)-OH, nonanoic acid, Fmoc-Thr(tBu)-OH.

[0521] The yield was 235 mg, representing a yield of 40.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1155.7 ([M+H)). + ).

[0522] Example 101: Preparation of (S)-6-methyloctanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-Phe-Thr-Dab-Dab-Thr] (Compound 101)

[0523] Compound 101 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, (S)-6-methyloctanoic acid, Fmoc-Thr(tBu)-OH.

[0524] The yield was 240 mg, representing a yield of 40.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1177.7 ([M+H)). + ).

[0525] Example 102: Preparation of 6-methylheptanoyl-Dab-Thr-D-Dap-cyclo(4-10)[Dab-Dab-Phe-Thr-Dab-Dab-Thr] (Compound 102)

[0526] Compound 102 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0527] The yield was 240 mg, representing a yield of 41.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1163.7 ([M+H)). + ).

[0528] Example 103: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser(CH2SO3H)-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 103)

[0529] Compound 103 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(CH2SO3H)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0530] The yield was 240 mg, representing a yield of 38.1% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0531] Example 104: Preparation of 6-methylheptanoyl-Dab-Thr(CH2SO3H)-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 104)

[0532] Compound 104 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(CH2SO3H)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, and Fmoc-Thr(tBu)-OH.

[0533] The yield was 245 mg, representing a yield of 38.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0534] Example 105: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr(CH2SO3H)-Dab-Dab-Thr] (Compound 105)

[0535] Compound 105 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(CH2SO3H)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0536] The yield was 248 mg, representing a yield of 39.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0537] Example 106: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr(CH2SO3H)] (Compound 106)

[0538] Compound 106 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(CH2SO3H)-OH.

[0539] The yield was 250 mg, representing a yield of 39.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0540] Example 107: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe(4-CH2SO3H)-Thr-Dab-Dab-Thr] (Compound 107)

[0541] Compound 107 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe(4-CH2SO3H)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0542] The yield was 260 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). +).

[0543] Example 108: Preparation of 6-methylheptanoyl-Dab(CH2SO3H)-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 108)

[0544] Compound 108 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(CH2SO3H)-OH, 6-methylheptanoic acid, and Fmoc-Thr(tBu)-OH.

[0545] The yield was 245 mg, representing a yield of 38.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0546] Example 109: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab(CH2SO3H)-D-Phe-Thr-Dab-Dab-Thr] (Compound 109)

[0547] Compound 109 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(CH2SO3H)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0548] The yield was 248 mg, representing a yield of 39.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)).+ ).

[0549] Example 110: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab(CH2SO3H)-Dab-Thr] (Compound 110)

[0550] Compound 110 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(CH2SO3)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0551] The yield was 250 mg, representing a yield of 39.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0552] Example 111: Preparation of 6-methylheptanoyl-Dab-Thr-D-Ser-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab(CH2SO3H)-Thr] (Compound 111)

[0553] Compound 111 was prepared under similar reaction conditions and purification methods as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-D-Ser(tBu)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH, Fmoc-Dab(CH2SO3H)-OH.

[0554] The yield was 260 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1258.6 ([M+H)). + ).

[0555] Example 112: Preparation of 6-methylheptanoyl-Dab-Thr-Dap(CH2SO3H)-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 112)

[0556] Compound 112 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(CH2SO3H)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0557] The yield was 240 mg, representing a yield of 38.2% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0558] Example 113: Preparation of 6-methylheptanoyl-Dab-Thr(CH2SO3H)-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 113)

[0559] Compound 113 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(CH2SO3H)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0560] The yield was 245 mg, representing a yield of 38.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0561] Example 114: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr(CH2SO3H)-Dab-Dab-Thr] (Compound 114)

[0562] Compound 114 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(CH2SO3H)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0563] The yield was 248 mg, representing a yield of 39.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0564] Example 115: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr(CH2SO3H)] (Compound 115)

[0565] Compound 115 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(CH2SO3H)-OH.

[0566] The yield was 250 mg, representing a yield of 39.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0567] Example 116: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe(4-CH2SO3H)-Thr-Dab-Dab-Thr] (Compound 116)

[0568] Compound 116 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe(4-CH2SO3H)-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0569] The yield was 260 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0570] Example 117: Preparation of 6-methylheptanoyl-Dab(CH2SO3H)-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr] (Compound 117)

[0571] Compound 117 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(CH2SO3H)-OH, 6-methylheptanoic acid, and Fmoc-Thr(tBu)-OH.

[0572] The yield was 245 mg, representing a yield of 38.9% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0573] Example 118: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab(CH2SO3H)-D-Phe-Thr-Dab-Dab-Thr] (Compound 118)

[0574] Compound 118 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(CH2SO3H)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0575] The yield was 248 mg, representing a yield of 39.4% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0576] Example 119: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab(CH2SO3H)-Dab-Thr] (Compound 119)

[0577] Compound 119 was prepared under the same reaction conditions and purification method as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Dab(CH2SO3)-OH, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH.

[0578] The yield was 250 mg, representing a yield of 39.7% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0579] Example 120: Preparation of 6-methylheptanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab(CH2SO3H)-Thr] (Compound 120)

[0580] Compound 120 was prepared under similar reaction conditions and purification methods as compound 1. The order in which the protected amino acid and the side-chain carboxylic acid were added to the reaction in the synthetic route was: Fmoc-Dab-OAllyl, Fmoc-Thr(tBu)-OH, Fmoc-D-Phe-OH, Fmoc-Dab(Boc)-OH, Fmoc-Dab(Dde)-OH, Fmoc-Dap(Boc)-OH, Fmoc-Thr(tBu)-OH, Fmoc-Dab(Boc)-OH, 6-methylheptanoic acid, Fmoc-Thr(tBu)-OH, Fmoc-Dab(CH2SO3H)-OH.

[0581] The yield was 260 mg, representing a yield of 41.3% based on the 0.5 mmol 2-Cl-Trt resin. Characterization of the purified peptide: purity (area integral of HPLC chromatogram) > 99.0%; ESI: m / z = 1257.7 ([M+H)). + ).

[0582] Experiment Example 1: Antibacterial Activity Experiment

[0583] The minimum inhibitory concentration (MIC) was determined using the microbroth dilution method recommended by CLSI.

[0584] Weigh appropriate amounts of the cyclic lipopeptide compounds and reference standards prepared in Examples 1-120, dissolve the samples in sterile pure water, and dilute an appropriate amount of the stock solution tenfold with sterile MH broth to 0.256 mg / mL. Dispense half the volume of the solution into a 96-well sample well, and dilute the other half twice with sterile MH broth before adding it to a deep-well sample well. Repeat the above steps to obtain drug concentrations in the sample wells of 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, and 0.06 mg / L, respectively, preparing each solution immediately before use. Select several colonies from agar plates cultured for 18-24 hours and prepare a bacterial suspension directly in sterile physiological saline, adjusting the concentration of the suspension to 0.5 McFarland units. Dilute the corrected bacterial suspension with MH broth to (4-8) × 10⁻⁶. 5 CFU / mL, freshly prepared and used immediately. Pipette 100 μL of the above-mentioned compounds of the present invention (e.g., the compounds prepared in the examples) and control solutions of different concentrations into wells 1 to 12 of a sterile 96-well polystyrene plate, respectively. Add 100 μL of the above-mentioned inoculum to each well. The final sample concentrations in the wells are 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.06, and 0.03 mg / L, respectively, and the final inoculum concentration is (2-4) × 10⁻⁴ mg / L for all wells. 5 CFU / mL. A separate growth control well was included, containing 100 μL of inoculum and 100 μL of sterile MH broth. The test sample and inoculum were mixed thoroughly in each well before sealing. The 96-well plate was incubated at 35-37℃ for 16-20 h. After incubation, bacterial growth was observed in each well, and the lowest drug concentration that completely inhibited bacterial growth in the well was determined as the minimum inhibitory concentration (MIC).

[0585] The strains used in the antimicrobial activity tests were obtained from the American Type Culture Collection (ATCC) and clinical isolates.

[0586] The strains used in the antibacterial activity test included Escherichia coli ATCC BAA-2523, ATCC BAA-2340 (KPC), Klebsiella pneumoniae KPN+19-15, ATCC BAA-1705 (KPC), Pseudomonas aeruginosa PAE19-3, ATCC27853, and Acinetobacter baumannii ABA19-1, NCTC13304 (OXA-27).

[0587] Test sample: A cyclic lipopeptide compound prepared according to the technical solution of this invention;

[0588] Reference standard: Polymyxin B.

[0589] result:

[0590] The anthropogenic activity of the cyclic polypeptide compounds of the present invention is shown in Table 2.

[0591] Table 2. Gram-negative bacterial activity (MIC, unit μg / mL) of the invented compounds.

[0592]

[0593]

[0594]

[0595]

[0596] Experiment Example 2: Nephrotoxicity Experiment

[0597] The CCK-8 assay was used to detect the in vitro cytotoxicity of HK-2 cells.

[0598] Human kidney HK-2 cells were cultured in RPMI-1640 complete medium (Invitrogen) containing 10% FBS (Gibco), and cryopreserved in 90% FBS + 10% DMSO in liquid nitrogen. Cells were cultured in a humidified incubator at 37°C with 5% CO2 until the cell density reached 70%-80%, then passaged. The cyclic lipopeptide compounds prepared in Examples 1-120 were weighed and dissolved in sterile water to a stock solution of 1 mg / mL to prepare drug-containing culture media. The final concentrations were 500, 250, 200, 100, 50, 25, and 12.5 μg / mL, respectively. A total of 5 × 10⁻⁶ cells were cultured. 4 Cells were seeded at a density of 100 μL / ml in 96-well plates, and cultured stably for 24 h. The medium was then replaced with the drug-containing medium, and the plates were incubated for 72 h. The medium was gently aspirated, and 100 μL of 10% CCK-8 blank medium was added. The plates were incubated for 3 h, and the OD value at 450 nm was measured using a BIOTEK microplate reader. The experiment was performed in triplicate, with polymyxin B as the positive control and a drug-free control as the blank control. Cell viability (%) was calculated as (OD of drug-treated group - OD zeroing) / (OD of drug-free group - OD zeroing) * 100%. The IC50 was calculated using log regression. 50 value.

[0599] Cells used in the renal cell toxicity assay were obtained from the American Type Culture Collection (ATCC). The Cell Counting Kit-8 (CCK-8) kit used in the renal cell toxicity assay was obtained from Beyotime Biotechnology.

[0600] Test sample: an antibacterial lipopeptide compound prepared according to the technical solution of the present invention;

[0601] Reference standard: Polymyxin B.

[0602] result:

[0603] The nephrotoxicity results of some of the cyclic polypeptide compounds of this invention are shown in Table 3.

[0604] Table 3 shows the human renal cell toxicity (IC50) of some of the invented compounds. 50 (unit: μg / mL)

[0605]

[0606]

[0607]

[0608]

[0609] Experiment Example 3: Acute toxicity test of compounds 2 and 7 in healthy mice

[0610] Healthy 5-6 week old ICR mice were selected, with 5-10 mice per group, and administered the drug via a single tail vein injection. The dosage was 20 mL / kg. After determining the drug concentration at which 100% mortality and no mortality occurred after a single intravenous injection in a preliminary experiment, 4-5 dosage groups were established within this dosage range, with a ratio of 1:0.5 to 1:0.8 between the groups. Animal mortality was recorded within 7 days after administration. The median lethal dose (LD50) of the test drug was calculated using the Bliss method based on the mortality rate of each group. 50 ), which is the dose that causes 50% of the test animals to die.

[0611] Mice in the solvent control group showed no abnormalities after a single tail vein injection of the solvent.

[0612] The mortality rates of compound 2 after a single tail vein injection at doses of 30, 24, 19.2, and 15.36 mg / kg were 100% (3 / 3), 62.5% (5 / 8), 25% (2 / 8), and 0% (0 / 8), respectively. The LD50 was... 50 The LD50 was 22.03 mg / kg (95% confidence limit: 19.61-24.79). The mortality rates for single tail vein injections of compound 7 at doses of 30, 24, 19.2, and 15.36 mg / kg were 100% (3 / 3), 25% (2 / 8), 12.5% ​​(1 / 8), and 0% (0 / 8), respectively. 50 The value was 24.43 mg / kg (95% confidence limit: 21.78-27.59).

[0613] Experimental Example 4: In vivo antibacterial test of compound 7

[0614] Pseudomonas aeruginosa ATCC27853 was selected for in vivo antibacterial activity testing.

[0615] The test bacteria were inoculated onto the appropriate nutrient agar plates one day before infection and cultured overnight. On the day of infection, a single colony was picked from the plate and placed into sterile physiological saline, mixed well, and this became the original bacterial solution. The bacterial solution was then prepared to the required concentration using 5% dry yeast powder and used immediately.

[0616] Healthy ICR mice were randomly divided into groups of five (half male and half female). Different dilutions of the bacterial solution were injected intraperitoneally into each mouse at a concentration of 0.5 mL / 20 g. Mice were observed for seven days post-infection, and the number of deaths was recorded. The lowest bacterial load that caused 100% mortality was defined as the minimum lethal bacterial load, which was used as the infectious bacterial load for in vivo protection tests.

[0617] The drug is administered via tail vein injection, with dosing frequency at 2h, 8h, 24h, and 30h post-infection, for a total of 4 doses. The dosage is 20mL / kg. The solution is prepared by dissolving compound 7, the control drug polymyxin B, and meropenem in physiological saline to the required concentration. The solution is prepared fresh and used immediately before tail vein injection.

[0618] After determining the drug concentration at which 100% of mice died and no mice died after infection with the test bacteria in the preliminary experiment, 4-5 dose groups were set within this dose range, with a dose group ratio of 1:0.5-1:0.8.

[0619] Mice were randomly divided into groups of eight (half male and half female) according to body weight. Each group was injected intraperitoneally with the test bacterial solution at a rate of 0.5 mL / 20 g. The bacterial solution was administered via tail vein injection at 2, 8, 24, and 30 hours post-infection. The blank control group was not infected with the bacterial solution but received only an equal volume of the solvent. The total drug volume was 20 mL / kg. The number of mouse deaths was observed and recorded for 7 consecutive days. Based on the number of deaths, the median effective dose (ED) was calculated using the Bliss method. 50 And 95% confidence limit, and statistical processing was performed.

[0620] The minimum lethal bacterial concentration (MDC) for intraperitoneal injection of *Pseudomonas aeruginosa* ATCC27853 in mice was 4.2 × 10⁻⁶. 2 CFU / mL, this bacterial count is used as the infectious bacterial count for the formal test.

[0621] The amount of MLD bacteria inoculated intraperitoneally in the control group mice was 4.0 × 10⁻⁶. 2Infection symptoms began to appear 3-4 hours after administration of Pseudomonas aeruginosa ATCC27853 bacterial suspension (CFU / mL). All 8 animals died within 48 hours (8 / 8), with a mortality rate of 100%.

[0622] Polymyxin B was administered twice daily for two days until the end of the observation period. The mortality rates of the animals in the 2 mg / kg and 1.4 mg / kg groups were 62.5% and 87.5%, respectively, while the mortality rates of the 1.0 mg / kg and 0.7 mg / kg groups were both 100%.

[0623] Meropenem was administered twice daily for two days until the end of the observation period. The mortality rate in the 20 mg / kg group was 0% (0 / 8); the mortality rates in the 10 mg / kg, 5 mg / kg, and 2.5 mg / kg groups were 37.5%, 62.5%, and 100%, respectively. ED5 and ED60 were also observed. 50 ED 95 The values ​​were 2.91 mg / kg, 7.07 mg / kg, and 17.19 mg / kg, respectively.

[0624] Compound 7 was administered twice daily for 2 days until the end of the observation period. The mortality rate in the 10 mg / kg dose group was 0% (0 / 8); the mortality rates in the 7 mg / kg, 4.9 mg / kg, and 3.4 mg / kg dose groups were 37.5%, 87.5%, and 100%, respectively. ED5 and ED60 were also observed. 50 ED 95 The values ​​were 4.54 mg / kg, 6.38 mg / kg, and 8.96 mg / kg, respectively.

[0625] Due to space limitations, only some experiments are described in the specification. Other compounds of the present invention also have the same or similar therapeutic effects.

[0626] In summary, some of the polymyxin compounds prepared by this invention have low nephrotoxicity, low acute toxicity, and high in vitro and in vivo antibacterial activity, and have the potential to become a new class of clinical antibiotics.

Claims

1. A cyclic basic lipopeptide compound or a pharmaceutically acceptable salt thereof, characterized in that, Selected from the following compounds: (6) (S)-6-methyloctanoyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr]; (7) 6-Methylheptanyl-Dab-Thr-Dap-cyclo(4-10)[Dab-Dab-D-Phe-Thr-Dab-Dab-Thr].

2. The cyclic basic lipopeptide compound or its pharmaceutically acceptable salt as described in claim 1, characterized in that, The pharmaceutically acceptable salts of the compound include salts formed by the compound and an acid selected from the group consisting of inorganic or organic acids, wherein the inorganic acid is selected from perchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid; and the organic acid is selected from acetic acid, trifluoroacetic acid, lactic acid, succinic acid, fumaric acid, maleic acid, citric acid, benzoic acid, methanesulfonic acid, or p-toluenesulfonic acid.

3. A pharmaceutical composition, characterized in that, The pharmaceutical composition comprises the cyclic basic lipopeptide compound of any one of claims 1-2 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient.

4. The use of the cyclic basic lipopeptide compound or its pharmaceutically acceptable salt as described in any one of claims 1-3 in the preparation of an antibacterial drug, wherein the antibacterial drug is an anti-Gram-negative bacterium drug.

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