10, 11-dehydrocurvulgarin 5-OH-esterified series derivatives as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of a dehydrocurvularia derivative and application of the dehydrocurvularia derivative in anti-drug-resistant bacteria drugs, and belongs to the technical field of medicines. The chemical structure of the derivative is shown as a formula I. The dehydrocurvularia derivatives modified by different substituent groups are prepared by taking 10, 11-dehydrocurvularia as a raw material, and the compounds not only can effectively inhibit the growth of staphylococcus aureus, but also have very good antibacterial activity on clinical methicillin-resistant staphylococcus aureus, and can be used for preparing medicines for treating the staphylococcus aureus. The application prospect of the compound in clinical infection treatment is shown.

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical technology, and specifically relates to a synthesis method of 10,11-dehydrocurvularin esterification derivatives and their application in the field of biomedicine. Background Art

[0002] The emergence of antibiotics has provided a powerful weapon for people to fight against bacterial infections. However, with the extensive use and even abuse of antibiotics, it has greatly accelerated the emergence and spread of "super bacteria" with high drug resistance, seriously threatening clinical anti-infection treatment. Therefore, it is urgent to develop new, highly efficient and low-toxic anti-infection drugs to deal with the increasingly serious drug-resistant bacterial infections.

[0003] The structural optimization of bioactive natural products is an important way to find new drugs. 10,11-dehydrocurvularin (abbreviated as DCV) is a polyketide compound of natural origin, and its structure consists of a meta-dihydroxybenzene ring and a twelve-membered lactone ring. The α,β-unsaturated ketone in the skeleton is its key pharmacophore. Literature reports that macrolide compounds have good pharmacological activities such as anti-tumor, antibacterial, antiviral and anti-inflammatory. The inventor of the present invention previously found that DCV has a wide range of inhibitory effects on various bacteria, and has a good effect on clinical methicillin-resistant Staphylococcus aureus. However, its molecular structure still has the defects of limited pharmacological activity and insufficient bioavailability. Through "tailor-made" structural modification, it is expected to develop it into a new anti-infection lead candidate drug, which is of great significance in the field of medicine. Summary of the Invention

[0004] The purpose of the present invention is to provide a 10,11-dehydrocurvularin 5-OH esterification derivative or a pharmaceutically acceptable salt thereof, and to improve its antibacterial activity and stability, providing a possibility for its further clinical development and application.

[0005] Another purpose of the present invention is to provide a preparation method of a series of derivatives and their application in the preparation of anti-infection drugs.

[0006] For this purpose, the present invention adopts the following technical solutions: On the one hand, the present invention provides a 10,11-dehydrocurvularin 5-OH esterification derivative, and the structure of the 10,11-dehydrocurvularin 5-OH esterification derivative is shown in Formula I:

[0007] Formula I Wherein R is selected from the following functional groups The organic acid selected: wherein R is selected from C1-C 20linear or branched halogenoalkyl, methoxy, oxygen-containing heterocyclic group, heterocyclic group, quinoline, thiazole, quinoxaline, imidazole, azaindole, pyrazine, oxazole, furan, indole, biphenyl, piperonyl ring, halogen atom-substituted heterocycle, naphthalene, anthracene, phenanthrene, pyrene and their halogen, methyl, methoxy and other substituents; halogen-substituted isonicotinic acid; alanine, phenylalanine, valine, leucine, isoleucine, tryptophan, aspartic acid, phenylglycine, glutamine, γ-aminobutyric acid, pyrrolidinecarboxylic acid, cyclobutanecarboxylic acid; chloromethyl, halogen, nitro-monosubstituted benzoic acid or disubstituted benzoic acid, etc.; On the other hand, the present invention provides a method for preparing a 10,11-dehydrocurvularin 5-OH esterification derivative as described above, and the preparation method includes the following steps: It includes the following reaction routes:

[0008] The synthesis method is as follows: Dissolve the substituted benzoic acid in a solvent, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine as catalysts at room temperature, add 10,11-dehydrocurvularin under stirring for reaction, and after the reaction is completed, the dehydrocurvularin 5-OH ester compound is prepared through purification.

[0009] The substituted benzoic acid is a linear or branched halogenoalkyl, methoxy, oxygen-containing heterocyclic group, heterocyclic group, quinoline, thiazole, quinoxaline, imidazole, azaindole, pyrazine, oxazole, furan, indole, biphenyl, piperonyl ring, halogen atom-substituted heterocycle, naphthalene, anthracene, phenanthrene, pyrene and their halogen, methyl, methoxy substituents; halogen-substituted isonicotinic acid; alanine, phenylalanine, valine, leucine, isoleucine, tryptophan, aspartic acid, phenylglycine, glutamine, γ-aminobutyric acid, pyrrolidinecarboxylic acid, cyclobutanecarboxylic acid; chloromethyl, halogen, nitro-monosubstituted benzoic acid or disubstituted benzoic acid of C1-C 20 linear or branched halogenoalkyl, methoxy, oxygen-containing heterocyclic group, heterocyclic group, quinoline, thiazole, quinoxaline, imidazole, azaindole, pyrazine, oxazole, furan, indole, biphenyl, piperonyl ring, halogen atom-substituted heterocycle, naphthalene, anthracene, phenanthrene, pyrene and their halogen, methyl, methoxy substituents; halogen-substituted isonicotinic acid; alanine, phenylalanine, valine, leucine, isoleucine, tryptophan, aspartic acid, phenylglycine, glutamine, γ-aminobutyric acid, pyrrolidinecarboxylic acid, cyclobutanecarboxylic acid; chloromethyl, halogen, nitro-monosubstituted benzoic acid or disubstituted benzoic acid.

[0010] The molar ratio of the substituted benzoic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine, and 10,11-dehydrocurvularin is 1:1.2-1.5:0.01-0.1:1.

[0011] The reaction temperature is room temperature, and the reaction time is 1-3 h.

[0012] The reaction solvent includes a solvent that can dissolve the substituted benzoic acid, and dichloromethane is selected in some preferred cases.

[0013] The purification step includes extraction, back extraction, drying, concentration, and column chromatography purification.

[0014] Compared with the prior art, the present invention has the following advantages and innovative points: (1) The preparation method of the 10,11-dehydrocurvularin 5-OH esterification derivative of the present invention is a novel method with mild conditions, simple process, low cost and environmental friendliness; this method is carried out under the action of a catalyst, which is convenient, inexpensive, easy to handle, and can react efficiently at room temperature; there is no use of dangerous carcinogenic reagents and it has good substrate applicability.

[0015] (2) The 10,11-dehydrocurvularin 5-OH-esterification derivative of the present invention has been structurally modified based on DCV and is a lead compound with potential antibacterial activity. The structural modification of active natural products is of great significance for the creation of new anti-infective drugs. The synthesis of the 5-OH-esterification derivative of the present invention also increases the scope of reaction substrates and the possibility of expanding biological activities. Specific Embodiments

[0016] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0017] Weigh an organic acid and dissolve it in 4 mL of dichloromethane. Add 1.3 equivalents of the catalyst 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and 4-dimethylaminopyridine (DMAP) under stirring at room temperature, and stir at room temperature for 0.5 h. Then add DCV. Monitor the reaction by thin-layer chromatography. After the reaction is completed, add 20 mL of saturated NaHCO3 to quench the reaction, and extract three times with saturated NaHCO3 solution and dichloromethane. Combine the aqueous layers and back-extract once. Combine the organic phases, dry over anhydrous Na2SO4, concentrate, and purify by column chromatography to obtain a pale yellow solid product. The synthetic route is shown as follows:

[0018] Example 1

[0019] Weigh phenylalanine (22.8 mg, 1.2 mmol) and dissolve it in 4 mL of dichloromethane. Stir in 1.3 equivalents of catalyst 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI, 17.4 mg) and 4-dimethylaminopyridine (DMAP, 0.1 mmol) at room temperature. After stirring at room temperature for 15 - 20 min, add DCV (25 mg, 1.0 mmol). Monitor the reaction by thin-layer chromatography. After the reaction is completed, extract three times with dichloromethane and saturated sodium bicarbonate solution, back-extract the aqueous phase once, dry over anhydrous sodium sulfate, concentrate under reduced pressure, mix the sample with silica gel, and purify by column chromatography using petroleum ether:ethyl acetate = 7:1. Finally, obtain 14 mg of a pale yellow solid product with a yield of 56%.

[0020] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H),7.30 – 7.18 (m, 5H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H),5.67 (d, J = 8.4 Hz,1H), 4.98 – 4.88 (m, 1H), 4.55 (d, J = 8.6 Hz, 1H),4.04 (d, J = 17.4 Hz, 1H),3.64 (d, J = 17.5 Hz, 1H),3.08 – 2.96 (m, 2H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30(m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17,171.85, 170.76, 163.21, 156.91, 155.32, 151.90, 137.03, 132.65, 128.96,127.27, 117.45, 116.55, 108.66, 80.06, 73.24, 55.49, 40.88, 37.43, 34.23,33.21, 28.33, 24.62, 20.27.。

[0021] Example 2

[0022] Weigh 28 mg of CBZ-L-valine to replace phenylalanine, and perform other operations as in Example 1 to obtain 10.5 mg of a pale yellow solid product, with a yield of 42%.

[0023] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H),7.38 – 7.32 (m, 4H), 7.32 –7.25 (m, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m,2H), 6.17 (d, J = 9.7 Hz, 1H), 5.08 (d, J = 0.8 Hz, 2H),4.98 – 4.88 (m, 1H), 4.04(d, J = 17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30(m, 2H), 2.16 – 2.10 (m, 1H), 2.05 – 1.87 (m, 2H), 1.34 (d, 3H), 0.94 (dd, J = 6.7, 1.3 Hz, 6H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 169.35, 163.21,156.31, 151.90, 137.08, 136.58, 132.65, 128.58, 128.39, 117.45, 116.55,108.66, 73.25, 66.37, 59.37, 40.88, 34.23, 33.21, 30.48, 24.62, 20.27,18.26.

[0024] Example 3

[0025] Weigh 17.9 mg of quinoline-6-carboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 8.8 mg of a pale yellow solid product, with a yield of 35.2%.

[0026] 11H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.96 (dd, J = 4.2, 1.8 Hz, 1H), 8.55 (d, J = 1.7 Hz, 1H), 8.38 (d, J = 8.7 Hz, 1H), 8.33 – 8.22 (m, 1H), 8.17(dd, J = 8.7, 1.9 Hz, 1H), 7.58 (dd, J = 7.6, 4.1 Hz, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04(d, J –17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30(m, 2H), 2.05 – 1.87 (m, 2H), 1.33 (d, 3H). 13 13C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 165.36, 163.28, 156.24, 151.90, 149.91, 148.37, 137.23, 132.65, 131.65, 130.81, 129.06, 128.73, 127.67, 127.27, 121.68, 117.42, 116.54, 108.45, 73.24, 40.88, 34.23, 33.21, 24.62, 20.27.

[0027] Example 4

[0028] Weigh 12.7 mg of pyridine carboxylic acid to replace phenylalanine, and perform other operations in the same manner as in Example 1 to obtain 19.1 mg of a pale yellow solid product with a yield of 76.4%.

[0029] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 9.18 (dd, J =2.0, 0.9 Hz, 1H), 8.73 (ddd, J = 4.8, 1.9, 0.9 Hz, 1H), 8.12 (dt, J = 8.0, 1.9 Hz, 1H), 7.46 (dd, J = 8.0, 4.9 Hz, 1H) 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59(m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.36, 156.28, 153.65, 151.90, 151.34, 137.45, 137.23, 132.65, 125.54, 123.60, 117.42, 116.58, 108.45, 73.25, 40.88, 34.23, 33.21, 24.62, 20.27.

[0030] Example 5

[0031] Weigh 16.6 mg of indolecarboxylic acid to replace phenylalanine, and perform other operations in the same way as in Example 1 to obtain 19.5 mg of a pale yellow solid product, with a yield of 78%.

[0032] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 9.18 (d, J = 6.6 Hz, 1H), 8.18– 8.14 (m, 1H), 8.14 – 8.06 (m, 2H), 7.22 (dd, J = 6.7, 3.1 Hz, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d,J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 6.60 (dd, J = 3.1, 1.1 Hz, 1H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 192.21, 171.39, 164.40, 154.39, 149.28, 137.07, 136.22, 133.55, 130.38, 129.04, 127.67, 124.87, 123.76, 122.47, 121.24, 113.60, 103.19, 73.24, 39.84, 34.23, 33.14, 24.62, 20.27.

[0033] Example 6

[0034] Weigh 22.2 mg of p - bromomethylbenzoic acid to replace phenylalanine, and perform other operations in the same way as in Example 1 to obtain 12.2 mg of a pale yellow solid product, with a yield of 48.8%.

[0035] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.05 – 7.99 (m, 2H), 7.47 (dt, J = 8.2, 1.0 Hz, 2H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75– 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.53 – 4.45 (m, 2H), 4.04 (d, J = 17.4 Hz, 1H), 3.64 (d, J =17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05– 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85,164.99, 163.26, 156.28, 151.90, 142.58, 137.23, 132.65, 131.45, 129.50,127.95, 117.42, 116.51, 108.45, 73.25, 40.88, 34.23, 33.21, 32.52, 24.62,20.27.。

[0036] Example 7

[0037] Weighed 17.8 mg of 2-naphthoic acid to replace phenylalanine, and other operations were the same as in Example 1, obtaining 23.3 mg of a pale yellow solid product with a yield of 93%.

[0038] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.48 (t, J J = 1.7 Hz, 1H), 8.40(d, J J = 8.5 Hz, 1H), 8.16 (dd, J J = 8.7, 1.6 Hz, 1H), 8.13 – 8.06 (m, 1H), 7.99 –7.91 (m, 1H), 7.63 – 7.54 (m, 2H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz,1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64(d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m,2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 165.56, 163.28, 156.29, 151.90, 137.23, 135.78, 133.63, 133.15, 132.65, 132.36, 130.45, 128.21, 127.81, 127.40, 127.13, 126.95, 117.42, 116.54, 108.45, 73.25, 40.88, 34.23, 33.21, 24.62, 20.27.

[0039] Example 8

[0040] 17.2 mg of 3,4 - methylenedioxybenzoic acid was weighed and used instead of phenylalanine, and other operations were the same as in Example 1, obtaining 14.2 mg of a pale yellow solid product with a yield of 56.8%.

[0041] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.68 (dd, J J = 8.6, 2.0 Hz, 1H), 7.58 (d, J J = 2.1 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.93 (m, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 6.00 (d, J J = 1.3 Hz, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ198.17, 171.85, 164.53, 163.28, 156.30, 151.85, 148.04, 137.23, 132.65,125.42, 123.56, 117.42, 116.57, 109.99, 109.20, 108.45, 101.67, 73.24, 40.88,34.23, 33.21, 24.62, 20.27.

[0042] Example 9

[0043] Weigh 11.6 mg of 3 - furan carboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 14.1 mg of a pale yellow solid product, with a yield of 56.4%.

[0044] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.20 (dd, J J = 1.8, 0.9 Hz, 1H),7.69 (t, J J = 1.7 Hz, 1H), 7.14 (dd, J J = 1.7, 0.8 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H),6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J =17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m,2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 13C NMR (100 MHz, CDCl3) δ 198.17,171.85, 163.34, 161.48, 156.28, 151.90, 148.70, 146.88, 137.23, 132.65,118.60, 117.36, 116.57, 108.45, 73.24, 40.88, 34.23, 33.21, 24.62, 20.27.

[0045] Example 10

[0046] Weigh 11.7 mg of oxazole-4-carboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 9.3 mg of a pale yellow solid product, with a yield of 37.2%.

[0047] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.27 (d, J J = 1.6 Hz, 1H), 8.16(d, J J = 1.6 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 –6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32(d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.24, 160.92, 155.14,151.90, 149.16, 144.49, 137.22, 134.07, 132.65, 117.42, 116.60, 108.48,73.25, 40.88, 34.23, 33.21, 24.62, 20.27.

[0048] Example 11

[0049] Weigh 16.8 mg of 7-azaindole-3-carboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 9.5 mg of a pale yellow solid product, with a yield of 38%.

[0050] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 9.60 (d, J= 7.1 Hz, 1H), 8.69(dd, J = 3.8, 2.2 Hz, 1H), 8.44 (dd, J = 7.5, 2.2 Hz, 1H), 8.23 (d, J = 7.1 Hz,1H), 7.42 (dd, J = 7.5, 3.8 Hz, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz,1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.64(d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m,2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.56, 163.28,155.93, 151.90, 148.48, 144.28, 137.23, 135.89, 132.65, 130.59, 118.52,118.36, 117.42, 116.61, 111.23, 108.45, 73.24, 40.88, 34.23, 33.21, 24.62,20.27.。

[0051] Example 12

[0052] 18 mg of 2 - quinoxalinecarboxylic acid was weighed instead of phenylalanine, and other operations were the same as in Example 1 to obtain 10.75 mg of a pale yellow solid product with a yield of 43 %.

[0053] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H),7.93 (s, 3H), 6.95 (d, J = 2.3Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 6.29 (d, J= 0.8 Hz, 1H), 6.27 (t, J = 1.4 Hz, 1H), 6.27 – 6.20 (m, 5H), 6.09 (dddd, J = 8.8, 7.9, 4.8, 2.0 Hz, 6H), 4.98 – 4.88 (m, 1H), 4.33 – 4.19 (m, 4H), 4.04 (d, J = 17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 165.66, 163.29, 157.45, 156.75, 151.90, 151.17, 137.18, 132.65, 125.97, 124.85, 124.68, 117.42, 116.17, 108.23, 73.25, 63.02, 60.67, 40.88, 34.23, 33.21, 24.62, 20.27.

[0054] Example 13

[0055] Weigh 13.3 mg of 3 - thiophenecarboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 9.75 mg of a pale yellow solid product, with a yield of 39%.

[0056] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.17 (t, J = 1.7 Hz, 1H), 7.78 (dd, J = 5.5, 1.6 Hz, 1H), 7.69 (dd, J = 5.5, 1.6 Hz, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d,J = 17.4 Hz, 1H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30(m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.28, 160.07, 156.30, 151.90, 137.23, 134.26, 133.02, 132.65, 131.01, 129.45, 117.42, 116.57, 108.45, 73.24, 40.88, 34.23, 33.21, 24.62, 20.27.

[0057] Example 14

[0058] 17.3 mg of bromoacetic acid was weighed instead of phenylalanine, and other operations were the same as in Example 1 to obtain 26 mg of a pale yellow solid product with a yield of 86%.

[0059] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 6.95 (d, J = 2.3 Hz, 1H), 6.81(d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4Hz, 1H), 3.99 (m, 2H), 3.64 (d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 165.69, 163.19, 155.15, 151.90, 137.07, 132.65, 117.47, 116.46, 108.64, 73.25, 40.88, 34.23, 33.21, 26.57, 24.62, 20.27.

[0060] Example 15

[0061] Weigh 14.6 mg of 5-fluoropyridine-2-carboxylic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 9.1 mg of a pale yellow solid product with a yield of 36.4%.

[0062] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.53 (dd, J J = 8.0, 2.0 Hz, 1H), 8.06 (dd, J J = 8.3, 5.0 Hz, 1H), 7.53 (td, J J = 8.1, 1.8 Hz, 1H), 6.95 (d, J J = 2.3Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.46, 163.25, 161.24, 155.14, 151.90, 144.54, 137.22, 136.98, 136.81, 132.65, 126.89, 122.57, 117.42, 116.47, 108.48, 73.25, 40.88, 34.23, 33.21, 24.62, 20.27.

[0063] Example 16

[0064] Weigh 19.2 mg of 3-fluoro-2-nitrobenzoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 8.9 mg of a pale yellow solid product with a yield of 35.6%.

[0065] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.96 (dd, J J = 7.3, 1.3 Hz, 1H),7.70 (td, J J = 7.4, 5.0 Hz, 1H), 7.57 (td, J J = 7.9, 1.4 Hz, 1H), 6.95 (d, J J = 2.3Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H),4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 –2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 13 13C NMR (100 MHz, CDCl3) δ198.17, 171.85, 163.33, 162.81, 155.77, 154.60, 152.59, 151.90, 137.14,136.29, 136.13, 132.65, 132.00, 127.18, 126.69, 120.16, 120.00, 117.42,116.57, 108.46, 73.25, 40.88, 34.23, 33.21, 24.62, 20.27.。

[0066] Example 17

[0067] Weigh 18.2 mg of 2,4,5 - trifluorobenzoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 15.7 mg of a pale yellow solid product, with a yield of 62.8 %.

[0068] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.74 (dt, J J = 8.0, 5.0 Hz, 1H),7.17 (td, J J = 8.0, 5.0 Hz, 1H), 6.95 (d,J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H),6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.64 (d, J =17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H),1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 163.34, 162.94, 159.53, 157.51, 155.90, 152.34, 151.90, 150.32, 148.62, 146.60, 137.23, 132.65, 119.48, 117.42, 116.57, 115.62, 108.45, 106.30, 73.25, 40.88, 34.23, 33.21, 24.62, 20.27.

[0069] Example 18

[0070] Weigh 18.6 mg of 3,5 - dimethyl - 4 - methoxybenzoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 18.6 mg of a pale yellow solid product, with a yield of 74.4%.

[0071] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.92 (s, 4H), 6.72 (d, J = 2.2Hz, 2H), 6.95 (d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H),4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.80 (s, 6H), 3.64 (d, J= 17.5Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.22 – 2.16 (m, 3H) 2.05 –1.87 (m, 2H), 1.32 (d, 3H). 13 C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 164.41,163.28, 160.13, 156.29, 151.90, 137.23, 132.65, 130.76, 128.36, 124.34,117.42, 116.54, 108.45, 73.25, 59.86, 40.88, 34.23, 33.21, 24.62, 20.27,15.99.。

[0072] Example 19

[0073] Weigh 18.8 mg of 3,5 - dimethoxybenzoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 20.1 mg of a pale yellow solid product with a yield of 80.4%.

[0074] 1 H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.28 (d, J = 2.4 Hz, 2H), 6.95(d, J = 2.3 Hz, 1H), 6.81 (d, J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 6.63 (t, J =2.3 Hz, 1H), 4.98 – 4.88 (m, 1H), 4.04 (d, J = 17.4 Hz, 1H), 3.81 (s, 6H), 3.64(d, J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m,2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 164.19, 163.28, 160.58, 156.29, 151.90, 137.23, 132.65, 130.93, 117.42, 116.57, 108.45, 108.18, 105.29, 73.25, 55.54, 40.88, 34.23, 33.21, 24.62, 20.27.

[0075] Example 20

[0076] Weigh 15.7 mg of 3 - methoxybenzoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 11.4 mg of a pale yellow solid product, with a yield of 45.6%.

[0077] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.80 (ddd, J J = 7.9, 1.6, 0.9Hz, 1H), 7.54 (t, J J = 1.8 Hz, 1H), 7.36 (d, J J = 8.0 Hz, 1H), 7.06 (ddd, J J = 7.9,1.7, 0.9 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59(m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.81 (s, 3H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m,2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 164.69, 163.28, 158.99, 156.30, 151.90, 137.23, 132.65, 130.80, 129.75, 124.42, 118.82, 117.42, 116.57, 114.60, 108.45, 73.25, 55.41, 40.88, 34.23, 33.21, 24.62, 20.27.

[0078] Example 21

[0079] 18.8 mg of 3,4 - dimethoxybenzoic acid was weighed instead of phenylalanine, and other operations were the same as in Example 1 to obtain 17.7 mg of a pale yellow solid product with a yield of 71%.

[0080] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 7.68 (dd, J J = 8.7, 2.1 Hz, 1H), 7.53 (d, J J = 2.1 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.87 (d, J J = 8.7 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.86 (d, J J = 2.4 Hz, 6H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 164.59, 163.28, 156.30, 153.26, 151.90, 149.25, 137.23, 132.65, 125.91, 123.48, 117.42, 116.57, 113.56, 112.37, 108.45, 73.24, 55.90, 40.88, 34.23, 33.21, 24.62, 20.27.

[0081] Example 22

[0082] 21.9 mg of 3,4,5 - trimethoxybenzoic acid was weighed instead of phenylalanine, and other operations were the same as in Example 1, obtaining 21 mg of a pale yellow solid product with a yield of 84%.

[0083] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.92 (dt, J J = 2.2, 1.1 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 6.72 (d, J J = 2.4 Hz, 1H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.87 (s, 6H), 3.80 (s, 3H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.17, 171.85, 164.81, 163.28, 156.29, 152.53, 151.90, 142.65, 137.23, 132.65, 124.17, 117.42, 116.57, 108.45, 107.89, 73.24, 60.76, 56.24, 40.88, 34.23, 33.21, 24.62, 20.27.

[0084] Example 23

[0085] Weigh 23 mg of 2 - anthraceneformic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 17.3 mg of a pale yellow solid product, with a yield of 40.3%.

[0086] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.65 (t, J J = 2.2 Hz, 1H), 8.60–8.52 (m, 2H), 8.23 – 8.14 (m, 2H), 8.00 (dt, J J = 6.2, 4.0, 3.2, 1.6 Hz, 2H), 7.52 (dd, J J = 6.0, 3.3 Hz, 2H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.16, 163.03, 156.34, 150.66, 137.05, 134.71, 132.25, 132.00, 131.33, 129.18, 128.65, 128.19, 127.24, 126.70, 126.12, 125.90, 117.20, 116.38, 108.35, 72.92, 40.56, 34.17, 32.58, 23.84, 20.15.

[0087] Example 24

[0088] Weigh 26 mg of 5-bromo-2-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 24.9 mg of a pale yellow solid product, with a yield of 55.3%.

[0089] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.53 (td, J J = 2.0, 0.6 Hz, 1H), 8.33 – 8.26 (m, 1H), 8.21 (dd, J J = 8.4, 1.9 Hz, 1H), 8.09 – 8.02 (m, 1H), 7.83 – 7.76 (m, 1H), 7.49 – 7.40 (m, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.16, 163.03, 156.34, 150.66, 137.05, 134.92, 133.31, 132.00, 129.79, 129.45, 128.55, 127.84, 127.10, 126.10, 122.93, 117.20, 116.38, 108.35, 72.90, 40.56, 34.17, 32.58, 23.84, 20.15.

[0090] Example 25

[0091] Weigh 26 mg of 5-bromo-1-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 16.8 mg of a pale yellow solid product with a yield of 37.3%.

[0092] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.61 – 8.54 (m, 1H), 8.33 (ddt, J J = 7.8, 1.1, 0.6 Hz, 1H), 8.30 – 8.24 (m, 1H), 7.78 (dd, J J = 8.0, 1.4 Hz, 1H), 7.65 (t, J J = 7.8 Hz, 1H), 7.46 (t, J J = 7.9 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.33, 163.03, 155.94, 150.66, 137.05, 134.10, 132.73, 132.00, 131.34, 131.01, 129.91, 129.39, 127.13, 126.50, 125.52, 121.89, 117.20, 116.41, 108.35, 72.92, 40.56, 34.17, 32.58, 23.84, 20.15.

[0093] Example 26

[0094] Weigh 21 mg of 6-methoxy-2-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 13.3 mg of a pale yellow solid product, with a yield of 32.4%.

[0095] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.44 (dq, J J = 2.1, 0.7 Hz, 1H), 8.09 (dd, J J = 8.2, 1.5 Hz, 1H), 7.93 (d, J J = 8.1, 2.1 Hz, 2H), 7.54 – 7.48 (m, 1H), 7.03 (dd, J J = 8.9, 2.4 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.83 (s, 3H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.22, 163.03, 156.96, 156.34, 150.66, 137.05, 135.81, 132.00, 129.88, 128.76, 128.37, 126.88, 126.16, 117.20, 116.38, 115.58, 108.35, 107.62, 72.92, 55.30, 40.56, 34.17, 32.58, 23.84, 20.15.

[0096] Example 27

[0097] Weigh 20 mg of 4-fluoro-1-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 20.5 mg of a pale yellow solid product with a yield of 51.5%.

[0098] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), δ 8.29 (ddd, J J = 7.8, 1.3, 0.7Hz, 1H), 8.13 – 8.04 (m, 2H), 7.61 (td, J J = 7.7, 1.3 Hz, 1H), 7.56 – 7.47 (m,1H), 7.38 – 7.30 (m, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H),6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J =17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H),1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.57, 163.38, 163.03, 160.86, 155.94, 150.66, 137.05, 132.62, 132.00, 131.41, 129.77, 126.57, 126.13, 125.41, 125.21, 123.40, 122.56, 117.20, 116.41, 111.24, 111.04, 108.35, 72.92, 40.56, 34.17, 32.58, 23.84, 20.15.

[0099] Example 28

[0100] Weigh 17.8 mg of 1-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 20.1 mg of a pale yellow solid product with a yield of 52.5%.

[0101] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.55 (ddt, J J = 8.5, 1.3, 0.6Hz, 1H), 8.30 (ddd, J J = 7.3, 1.2, 0.6 Hz, 1H), 8.15 – 8.04 (m, 2H), 7.69 – 7.59 (m, 2H), 7.58 – 7.49 (m, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.86, 163.03, 155.94, 150.66, 137.05, 133.42, 132.00, 130.93, 130.72, 130.40, 129.43, 127.44, 126.52, 125.63, 125.50, 125.33, 117.20, 116.41, 108.35, 72.92, 40.56, 34.17, 32.58, 23.84, 20.15.

[0102] Example 29

[0103] 19.3 mg of 4-methyl-1-naphthoic acid was weighed and used instead of phenylalanine. Other operations were the same as in Example 1 to obtain 25.2 mg of a pale yellow solid product with a yield of 63.8%.

[0104] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.24 – 8.17 (m, 1H), 8.06 (ddt, J J = 7.7, 1.3, 0.6 Hz, 1H), 8.00 (dd, J J = 8.4, 0.5 Hz, 1H), 7.60 (td, J J = 7.7, 1.2 Hz, 1H), 7.50 (td, J J = 7.7, 1.3 Hz, 1H), 7.40 – 7.32 (m, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.97, 163.03, 155.94, 150.66, 137.59, 137.05, 132.60, 132.00, 130.53, 128.54, 127.84, 126.41, 125.19, 124.25, 117.20, 116.41, 108.35, 72.90, 40.56, 34.17, 32.58, 23.84, 20.15, 19.68.

[0105] Example 30

[0106] Weigh 20.9 mg of 4-methoxy-1-naphthoic acid to replace phenylalanine, and perform other operations as in Example 1 to obtain 10.1 mg of a pale yellow solid product with a yield of 24.7%.

[0107] 1 1H NMR (400 MHz, CDCl3) δ 11.35 (s, 1H), 8.20 (tdd, J J = 8.3, 1.8, 0.8 Hz, 2H), 8.02 (dd, J J = 8.6, 0.4 Hz, 1H), 7.63 – 7.49 (m, 2H), 7.08 (dd, J J = 8.6, 0.4 Hz, 1H), 6.95 (d, J J = 2.3 Hz, 1H), 6.81 (d, J J = 2.3 Hz, 1H), 6.75 – 6.59 (m, 2H), 4.98 – 4.88 (m, 1H), 4.04 (d, J J = 17.4 Hz, 1H), 3.95 (s, 3H), 3.64 (d, J J = 17.5 Hz, 1H), 2.59 – 2.48 (m, 2H), 2.42 – 2.30 (m, 2H), 2.05 – 1.87 (m, 2H), 1.32 (d, 3H). 1313C NMR (100 MHz, CDCl3) δ 198.01, 171.80, 165.73, 163.03, 158.83, 155.94, 150.66, 137.05, 133.61, 131.92, 129.40, 125.75, 125.42, 123.70, 123.02, 117.20, 116.41, 110.41, 108.35, 72.92, 55.18, 40.56, 34.17, 32.58, 23.84, 20.15.

[0108] Example 31 Antibacterial activity of the compound Autoclaving and ultraviolet sterilization: Autoclave at 121 °C for 15 min to autoclave different specifications of pipette tips, EP tubes, centrifuge tubes, pipette boxes, EP tube racks, glass bottles and culture media; before the experiment, lay the above autoclaved items, vortex mixer, pipettes of various specifications, marker pens, and 96-well plates flat in the laminar flow hood and sterilize with ultraviolet light for 30 min for standby.

[0109] Strain culture Inoculate the strain to be screened on the flat solid medium, use a 10 μL pipette tip to aspirate monoclonal colonies and inject them into a shaking tube with 3 mL of culture medium, and shake-culture the first-generation strain at an appropriate temperature, rotation speed and time. After the end of the shaking culture, the absorbance of the first-generation strain measured by the microplate reader reaches above 1.0; 8 - 10 hours before the experiment, aspirate 3 μL from the first-generation strain and inject it into a shaking tube with 3 mL of culture medium according to a dilution ratio of 1:1000 to obtain the second-generation strain, and measure OD before the experiment. 600 It can be used when it reaches above 1.0.

[0110] Prepare OD 600 value and drug concentration Take 200 μL of the second-generation strain in an EP tube, add culture medium to dilute to an absorbance value of 0.4, and then take the corresponding absorbance value of 0.4 and dilute it to 0.04 according to a ratio of 1:1000 for standby; use DMSO to dilute the derivative to 100 mg / ml and then dilute it proportionally to 15 mg / mL and 2 mg / mL for standby.

[0111] 96-well plate and OD 600 value measurement Add the compound to the bacterial solution with an OD 600 value of 0.04 to prepare concentrations of 0, 1, 2, 4, 8, 16, 32, 64 μg / mL, make four replicates, add 200 μL each, and measure at 0 and 24 h respectively, and summarize the results.

[0112] Table 2 In vitro antibacterial activities of derivatives

[0113] a The MIC is the average value of at least three independent experiments; HC 50 is hemolytic toxicity. The larger this value is, the lower the toxicity; VAN is vancomycin.

[0114] The series of compounds of the present invention are roughly divided into three categories according to the modification idea of splicing the pharmacophores of active natural products, progressing layer by layer. First, a nitrogen-containing heterocycle is selected as a substituent, and then the dominant fragments of benzene ring and substituted benzene ring are introduced. As can be seen from Table 2, the activities of most DCV derivatives substituted with benzene ring are better than those substituted with heterocycle. Further structure-activity analysis reveals that the antibacterial activity of the fused-ring structure is significantly enhanced, and the activity of fused-ring substitution is better than that of substituted benzene ring and heterocycle. Among them, the derivative a27 has the best activity, and the antibacterial activity of some is comparable to that of the positive control vancomycin.

[0115] The above embodiments are the preferred embodiments selected for the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other modifications, changes, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

[0116] Example 32 In vitro erythrocyte hemolysis reaction of the compound (1) Preparation of 5% erythrocyte suspension: Take 1 mL of fresh, sterile, defatted sheep blood in a centrifuge tube and centrifuge at 3500 rpm for 5 min (4 °C), then aspirate the supernatant. After that, add 2 - 3 mL of PBS, shake well, centrifuge the precipitate, and discard the supernatant. Then add 2 - 3 mL of normal saline and wash according to the above method three times (the supernatant is no longer turbid after centrifugation). Take the packed erythrocytes and configure them into a 0.5% suspension with PBS.

[0117] 100 ml normal saline + 0.5 ml packed erythrocytes (precipitated blood after centrifugation) = 0.5%; (2) Preparation of 0.1% TritonX-100 solution: Take 1 μL of TritonX-100 and add it to 999 μL of PBS solution for preparation.

[0118] (3) Preparation of sample solution: The sample concentrations were set at 1024 μg / mL, 512 μg / mL, 256 μg / mL, 128 μg / mL, 64 μg / mL, and 32 μg / mL. Dissolve with a small amount of DMSO (the final concentration of DMSO should not exceed 0.5%). After dissolving in DMSO, dilute with PBS. Take 1.5 μL of the 1024 μg / mL sample and add it to 1.5 mL of PBS. Add 1 mL of PBS to the remaining centrifuge tubes. Take 0.5 mL of the 1024 μg / mL PBS mixture and add it to prepare a concentration of 512 μg / mL. Use the serial dilution method and repeat successively.

[0119] (4) Drug addition and incubation: Mix the prepared 5% red blood cell suspension, take 600 μL and add it to a centrifuge tube, then add the corresponding 200 μL of drug sample (repeat 4 times for each gradient). The negative control group is 200 μL of PBS solution, and the positive control group is 200 μL of 0.1% Triton X-100 solution. After adding, place it in an incubator at 37 °C for 1 h.

[0120] (5) Post-treatment and plating: Take the centrifuge tube out of the incubator and centrifuge it in a 4 °C centrifuge (3500 rpm, 5 min). After centrifugation, correspondingly aspirate 100 μL of the supernatant in the centrifuge tube and make 4 replicate wells on the microplate. After aspiration, measure the absorbance value at 540 nm in an enzyme-linked immunosorbent assay (ELISA) reader.

[0121] Red blood cell hemolysis rate = (A - A0) / (A total - A0) × 100 A is the absorbance of the drug to be tested, A0 is the absorbance of the negative control, and A total is the absorbance of the positive control group. Fit the data to obtain HC 50 .

[0122] For the in vitro red blood cell hemolysis reaction, only some compounds were selected, from compound a1 to a30, as well as the DCV parent nucleus structure, a total of 31 compounds. The results showed that the hemolytic toxicity of all derivatives to mammalian cells was greater than 1024 μg / mL. Among them, the MIC of derivative a27 against the selected strains was 2 - 4 μg / mL, and the antibacterial activity was increased by 16 times compared with DCV.

Claims

1. A 10,11-dehydrocurvularin 5-OH-esterification derivative, characterized in that, Comprising a compound having the structure shown in Formula I: General formula I wherein R is selected from straight-chain or branched halogenoalkyl having 1 to 20 carbon atoms, methoxy, oxygen-containing heterocyclic group, heterocyclic group, quinoline, thiazole, quinoxaline, imidazole, azaindole, pyrazine, oxazole, furan, indole, biphenyl, piperonyl, heterocycle substituted by halogen atom, naphthalene, anthracene, phenanthrene, pyrene and their halogen, methyl, methoxy substituent; halogen-substituted isonicotinic acid; alanine, phenylalanine, valine, leucine, isoleucine, tryptophan, aspartic acid, phenylglycine, glutamine, γ-aminobutyric acid, pyroglutamic acid, cyclobutanecarboxylic acid; chloromethyl, halogen, nitro-monosubstituted benzoic acid or disubstituted benzoic acid.

2. The 5-OH-esterified derivative of 10,11-dehydrocurvularin according to claim 1, wherein The 10,11-dehydrocurvularin 5-OH-esterified derivative is selected from any one of the following compounds: Table 1 Examples of compound structures 。 3. The preparation method of the 10,11-dehydrocurvularin 5-OH-esterified derivative according to claim 1 or 2, characterized in that, It includes the following reaction routes: The synthesis method is as follows: Dissolve the substituted benzoic acid in a solvent, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine as catalysts at room temperature, add 10,11-dehydrocurvularin under stirring for reaction, and after the reaction is completed, the 10,11-dehydrocurvularin 5-OH ester compound is obtained through purification.

4. The preparation method of the 10,11-dehydrocurvularin 5-OH-esterification derivative according to claim 3, characterized in that, The substituted benzoic acid is a straight-chain or branched-chain halogenoalkyl, methoxy, oxygen-containing heterocyclic group, heterocyclic group, quinoline, thiazole, quinoxaline, imidazole, azaindole, pyrazine, oxazole, furan, indole, biphenyl, piperonyl ring, halogen atom-substituted heterocycle, naphthalene, anthracene, phenanthrene, pyrene and their halogens, methyl, methoxy substituents; halogen-substituted isonicotinic acid; alanine, phenylalanine, valine, leucine, isoleucine, tryptophan, aspartic acid, phenylglycine, glutamine, γ-aminobutyric acid, proline, cyclobutanecarboxylic acid; chloromethyl, halogen, nitro-monosubstituted benzoic acid or disubstituted benzoic acid. 20 ​ 5. The preparation method of the 10,11-dehydrocurvularin 5-OH-esterified derivative according to claim 3, characterized in that The molar ratio of the substituted benzoic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine, and 10,11-dehydrocurvularin is 1:1.2 - 1.5:0.01 - 0.1:

1.

6. A fungicide, characterized in that, The active ingredient of the fungicide is selected from the 10,11-dehydrocurvularin esterified derivatives described in claim 1 or 2.

7. The fungicide according to claim 5, characterized in that, The application of the 10,11-dehydrocurvularin esterified derivative described in claim 1 or 2 in the preparation of antibacterial agents.

8. The fungicide according to claim 6, characterized in that, The antibacterial property is the antibacterial effect against any one or more of Staphylococcus aureus, MRSA300, MRSA996, MRSA131, MRSA602, Escherichia coli, Proteus, Salmonella, Bacillus subtilis, and Alternaria solani.

9. A pharmaceutical composition, characterized in that, Comprising the 10,11-dehydrocurvularin esterified derivative according to any one of claims 1 - 2.

10. The application of the composition according to claim 9 in the preparation of antibacterial agents, wherein the antibacterial property is the antibacterial effect against any one or more of Staphylococcus aureus, MRSA300, MRSA996, MRSA131, MRSA602, Escherichia coli, Proteus, Salmonella, Bacillus subtilis, and Alternaria solani.

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