Iron(III) macrocyclic complex with mixed hydroxyl pendants as an MRI contrast agent

Abstract

This provides a macrocyclic complex for improving in vivo MR imaging. [Solution] A novel Fe(III) macrocyclic complex having a hydroxy pendant with a third anionic auxiliary is provided. This complex has the following general structure: TIFF2026136141000214.tif33169 High-spin Fe(III) is chelated into a macrocyclic core having the structure of formula (I) or formula (II).

Description

Cross-reference of related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 163,822, filed on 20 March 2021, and U.S. Provisional Patent Application No. 63 / 176,193, filed on 16 April 2021, the disclosures of which are incorporated herein by reference.

[0002] [Statement regarding federal government-sponsored research] This invention was developed with government support under authorization number STTR-1951127, granted by the National Science Foundation. The government has certain rights to this invention. Background of Disclosure

[0003] Almost all contrast agents used clinically contain gadolinium (Gd as trivalent Gd(III)), but administering Gd(III) contrast agents is considered dangerous for a significant proportion of the US population (about 10%) due to toxicity resulting from long-term exposure. Furthermore, there is a growing concern that Gd(III)-based MRI contrast agents are leading to Gd(III) deposition in the brain, bones, and skin of all patients. As an alternative to Gd(III) contrast agents, there are biologically suitable transition metal ions, such as high-spin Fe(III) complexes.

[0004] One alternative approach in magnetic resonance imaging (MRI) is the development of contrast agents utilizing iron as an endogenous metal ion. Contrast agents containing Fe(III) as trivalent iron can serve as an alternative to Gd(III) contrast agents, which are problematic for patients who cannot tolerate Gd(III). Most Fe(III) MRI contrast agents reported to date contain simple linear chelates. There are three types of complexes commonly used. The most extensively studied type contains an ethylenediamine skeleton with a combination of phenol and carboxylic acid pendants, such as EHBG (NN'-ethylenebis[(2-hydroxybenzyl)glycine). The second type contains polyaminocarboxylic acid ligands, such as the Fe(III) complex of EDTA. The third type contains desferrioxamine (DFO), a bacterial siderophore. All of these complexes have drawbacks, such as the lack of interchangeable water ligands, a reduction potential that easily produces ROS, and / or difficulties in synthetic modification. Furthermore, the aqueous solution chemistry of Fe(III) complexes is dominated by the formation of insoluble complexes between hydroxides and bridging oxide ligands. Improvements are needed to obtain Fe(III) complexes that are water-soluble and desirable as T1 relaxants, rather than catalysts that easily generate ROS by adjusting the redox potential to stabilize Fe(III). [Overview of the project]

[0005] This application describes a novel Fe(III) macrocyclic complex having a hydroxypendant with a third anionic auxiliary for improving in vivo MR imaging. The complex has the following general structure, with high-spin Fe(III) chelated thereto: [ka] This application also describes a novel Fe(III) macrocyclic complex having a hydroxypropyl pendant with a third anionic auxiliary for improving in vivo MR imaging. This complex has the following general structure: [ka]

[0006] In one embodiment, the disclosure provides a macrocyclic compound having i) a macrocyclic core containing at least one heteroatom as a ligand donor, and ii) at least one pendant donor as a substituent of the macrocyclic core. When the macrocyclic compound coordinates to an iron(III) ion, the macrocyclic compound may be called a ligand. The macrocyclic core has a ring structure containing a carbon atom and at least one heteroatom (e.g., a nitrogen atom). As used herein, “macrocyclic donor” means a heteroatom that, when present in the macrocyclic core of a macrocyclic compound, has a lone pair of electrons available to donate to the iron(III) center. For example, a macrocyclic donor may be a nitrogen atom (e.g., a tertiary amine, a secondary amine). As used herein, “pendant donor” means a heteroatom that, when present in a substituent on the macrocyclic core of a macrocyclic compound, has a lone pair of electrons available to donate to the Fe(III) center. For example, the pendant donor may be a nitrogen-containing group (e.g., amino, benzimidazole, imidazole, aniline, pyrazoyl, triazole, benzotriazole, etc.) or an oxygen-containing group (e.g., ketone, alcohol, alkoxide, amide, phosphonic acid, carboxylic acid, etc.). Some pendant donors (e.g., carboxylic acids, alcohols, imidazole, pyrazole, etc.) may complex with Fe(III) or deprotonate at a specific pH. Such forms of protonation and deprotonation are within the scope of this disclosure. For example, the pendant donor may be a phosphonate, phosphinate, phenolate, or oxide (e.g., alkoxide or phenoxide). [Brief explanation of the drawing]

[0007] For a deeper understanding of the nature and purpose of this disclosure, please refer to the following detailed explanation along with the attached diagrams.

[0008] [Figure 1] Figure 1 shows a typical synthesis of TACN(1,4,7-triazacyclononane) derivatives. a) N,N-dimethylformamide dimethylacetal, toluene / chloroform 4:1. b) RX; R = benzyl, methyl, propargyl, methylphenyl, methyl benzoate, 2-(2-methoxy-ethoxy)ethane, 4-(methyl)-1,1'-biphenyl, benzyl methyl ether; dry THF, X = chloro, bromo or iodine. c) Reflux; extract with 12M HCl / MeOH 1:1 or KOH solution, then with chloroform. d) Addition of coordination pendants (bromomethyl-pyrazole, bromoacetamide, etc.) by the addition of chloro or bromomethyl derivatives. Addition of pendants by reductive amination by the addition of an aldehyde with a reducing agent such as imidazole-2-carboxyaldehyde. Addition of pendants by the addition of an H2O / ethanol mixture with (S)-(-)propylene oxide or (R)-(+)propylene oxide.

[0009] [Figure 2] Figure 2 shows a typical synthesis of a TACN ligand with two chiral propyl alcohol pendants. Using either R or S propylene oxide can yield pendants with opposite chiralities. The non-coordinating group R is typically benzyl, methyl, or biphenyl.

[0010] [Figure 3] Figure 3 shows the synthesis of the TON ligand, a precursor of the TOB ligand. The benzyl group is removed by catalytic hydrogenation to produce TON.

[0011] [Figure 4] Figure 4 shows the changes in signal intensity up to 4 hours after Fe(TOP) injection in the liver, kidney, gallbladder, and vena cava of healthy Balb / C mice (0.050 mmol / kg, 4.7T).

[0012] [Figure 5] Figure 5 shows the changes in signal intensity up to 4 hours after Fe(TOP) injection in the liver, kidney, gallbladder, and vena cava of healthy Balb / C mice (0.050 mmol / kg, 4.7T).

[0013] [Figure 6] Figure 6 shows the time course of signal intensity (T1-weighted imaging) after Fe(TOP) injection in the blood (vena cava, kidney, liver) of healthy Balb / C mice administered 0.050 mmol / kg of iron or 0.10 mmol / kg of DOTAREM. Imaging was performed using a 4.7T MRI scanner with healthy Balb / C mice.

[0014] [Figure 7] Figure 7 shows the changes in signal intensity after infusion of FeFCPT2 and FCPYPT in the liver, kidney, renal blood vessels, hepatic and vena cava of healthy BALB / c mice (4.7T, 0.05 mmol / kg dose or 0.100 dose of iron), compared to the Gd(III) agents Gd-DOTA or Gd(DTPA). Healthy BALB / c mice were imaged using a 4.7T MRI scanner.

[0015] [Figure 8] Figure 8 shows an example of T1-weighted MRI (4.7T) of Fe(L1) in healthy BALB / C mice. The figure shows the changes in signal intensity after injection of Fe(TPP) in the liver, kidney, renal blood vessels, liver, and vena cava (4.7T · 0.100 mmol / kg dose) in healthy BALB / c mice, compared to the Gd(III) agents Gd-DOTA (Dotarem) or Gd(DTPA). Detailed explanation of disclosure

[0016] While the claimed subject matter is described in terms of specific embodiments, other embodiments, including those that do not provide all of the advantages and features described herein, are also within the scope of this disclosure. Various structural, logical, and process step modifications can be made without departing from the scope of this disclosure.

[0017] This specification discloses ranges of values. A range is defined by a lower limit value and an upper limit value. Unless otherwise specified, a range includes the lower limit value, the upper limit value, and all values between the lower limit value and the upper limit value (including, but not limited to, all values up to the digit of the minimum value (either the lower limit value or the upper limit value)).

[0018] In this application, the use of the singular form encompasses the plural form and vice versa.

[0019] As used herein, unless otherwise specified, the term "group" refers to a chemical entity that is monovalent (i.e., having one terminus capable of covalently bonding to other chemical species), divalent, or polyvalent (i.e., having two or more termini capable of covalently bonding to other chemical species). The term "group" also includes radicals (e.g., monovalent and polyvalent radicals, such as divalent, trivalent, etc. radicals). Examples of groups include the following:

Chemical formula

[0020] As used herein, unless otherwise specified, the term "alkyl group" refers to a branched or unbranched straight-chain saturated hydrocarbon group and / or a cyclic hydrocarbon group. Examples of alkyl groups include, but are not limited to, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc. An alkyl group is a saturated group unless it is a cyclic group. For example, an alkyl group includes all integer numbers of carbon atoms and ranges of carbon atoms between them, C1~C 30 which is an alkyl group (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 , C 16 , C 17 , C 18 , C 19 , C 20 , C 21 , C 22, C 23 , C 24 , C 25 , C 26 , C 27 , C 28 , C 29 , and C 30 ). The alkyl group may be unsubstituted or substituted with one or more substituents. Examples of substituents include, but are not limited to, halogens (-F, -Cl, -Br, -I), aliphatic groups (e.g., alkyl groups, alkenyl groups, alkynyl groups, etc.), halogenated aliphatic groups (e.g., trifluoromethyl group, etc.), aryl groups, aryl halides, alkoxide groups, amine groups, nitro groups, carboxylate groups, carboxylic acids, ether groups, alcohol groups, alkyne groups (e.g., acetylenyl group, etc.), and combinations thereof.

[0021] As used herein, unless otherwise specified, the term "aryl group" refers to a C5-C 30 This refers to an aromatic or partially aromatic carbocyclic group, including all integer carbon numbers and the range of carbon numbers between them (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 , C 16 , C 17 , C 18 , C 19 , C 20 , C 21 , C 22 , C 23 , C 24 , C 25 , C 26 , C 27 , C 28 , C 29 , and C 30). Aryl groups are sometimes called aromatic groups. Aryl groups may include polyaryl groups such as fused rings, biaryl groups, or combinations thereof. Aryl groups may be unsubstituted or substituted with one or more substituents. Examples of substituents include, but are not limited to, halogens (-F, -Cl, -Br, -I), aliphatic groups (e.g., alkyl groups, alkenyl groups, alkynyl groups, etc.), aryl groups, alkoxides, carboxylates, carboxylic acids, ether groups, etc., and combinations thereof. Examples of aryl groups include, but are not limited to, phenyl groups, biaryl groups (e.g., biphenyl groups, etc.), fused ring groups (e.g., naphthyl groups, etc.), hydroxybenzyl groups, tolyl groups, xylyl groups, furanyl groups, benzofuranyl groups, indolyl groups, imidazolyl groups, benzimidazolyl groups, pyridinyl groups, etc.

[0022] As used herein, unless otherwise specified, the term “heteroaryl group” refers to a C1-C group comprising one or two aromatic rings containing at least one heteroatom (e.g., nitrogen, oxygen, sulfur, etc.) in the aromatic ring. 14 Monocyclic, polycyclic, or bicyclic groups (e.g., aryl groups) (the carbon number includes all integer carbon numbers and ranges of carbon numbers between them, e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C) 10 , C 11 , C 12 , C 13 , C 14This refers to heteroaryl groups (which include...). Heteroaryl groups may be substituted or unsubstituted. Examples of heteroaryl groups include, but are not limited to, benzofuranyl, thienyl, furyl, pyridyl, pyrimidyl, oxazolyl, quinolyl, thiophenyl, isoquinolyl, indolyl, triazinyl, triazolyl, isothiazolyl, isoxazolyl, imidazolyl, benzothiazolyl, pyrazinyl, pyrimidinyl, thiazolyl, and thiadiazolyl groups. Examples of substituents include, but are not limited to, halogens (-F, -Cl, -Br, -I), aliphatic groups (e.g., alkyl groups, alkenyl groups, alkynyl groups, etc.), aryl groups, alkoxide groups, amine groups, carboxylate groups, carboxylic acids, ether groups, alcohol groups, alkyne groups (e.g., acetylenyl group, etc.), and combinations thereof.

[0023] This application describes a novel Fe(III) macrocyclic complex having a hydroxy pendant with a third anionic auxiliary for improved in vivo MR imaging. This application also describes a novel Fe(III) macrocyclic complex having a hydroxypropyl pendant with a third anionic auxiliary for improved in vivo MR imaging.

[0024] Contrast agents must be sufficiently hydrophilic to prevent strong protein binding and promote pharmacokinetic clearance in vivo. One way to achieve this is to add a tri(hydroxy)butyl group as a pendant to macrocyclic compounds or Fe(III) macrocyclic complexes, as shown here.

[0025] The object of this disclosure is to provide macrocyclic compounds that may be Fe(III) macrocyclic complexes. Compositions, methods for producing the same, and methods for using them are also provided. In various examples, the macrocyclic complexes and compositions of this disclosure are used as MRI contrast agents. This application further describes a novel Fe(III) macrocyclic complex having a tri(hydroxy)butyl pendant group. The tri(hydroxy)butyl pendant group has three alcohol groups for stronger interaction between the complex and water. This macrocyclic complex improves in vivo MR imaging.

[0026] The macrocyclic compounds disclosed herein as ligands are advantageous for controlling the spin and oxidation state of Fe(III) complexes, as well as for achieving interactions with water in the inner and outer spheres of the complex, proton exchange, or hydroxyalkyl group-mediated interactions. The cavities of these macrocyclic ligands are suitable for stabilizing iron(III) in a high-spin state. Furthermore, control of the aqueous solution chemistry of Fe(III) complexes can be achieved using these macrocyclic compounds. The macrocyclic complexes described herein almost completely encapsulate iron(III), but in some cases, they have a coordination site for a water ligand, which enhances their efficiency as T1 MRI contrast agents. The compounds also have protons on the hydroxyalkyl pendant. Although not intended to be bound by any particular theory, it is thought that the protons on the hydroxyalkyl pendant group contribute to improved relaxation through exchange with bulk water protons. While not intended to be bound by any particular theory, the iron-based MRI contrast agents described herein (as high-spin, trivalent Fe(III)) are thought to produce contrast through the paramagnetic mechanism known for Gd(III) agents and exist in the form of small molecules as coordination complexes, i.e., not as iron oxide-based nanoparticles.

[0027] In this disclosure, macrocyclic compounds have various macrocyclic core structures and various substituents on the macrocyclic core (also referred to as "pendant donor groups," "pendant groups," "pendant donors," or "donor groups"). Most typically, the donor groups include amides, alcohols, or phenols, but have at least two alcohol groups or other groups that can be deprotonated to form an anionic group. The macrocyclic compounds are complexed with Fe(III) to provide a stabilized trivalent state.

[0028] In one embodiment, the disclosure provides a macrocyclic compound having i) a macrocyclic core containing at least one heteroatom as a ligand donor, and ii) at least one pendant donor as a substituent of the macrocyclic core. When the macrocyclic compound coordinates to an iron(III) ion, the macrocyclic compound may be called a ligand. The macrocyclic core has a ring structure containing a carbon atom and at least one heteroatom (e.g., a nitrogen atom). As used herein, “macrocyclic donor” means a heteroatom that, when present in the macrocyclic core of a macrocyclic compound, has a lone pair of electrons available to donate to the iron(III) center. For example, a macrocyclic donor may be a nitrogen atom (e.g., a tertiary amine, a secondary amine). As used herein, “pendant donor” means a heteroatom that, when present in a substituent on the macrocyclic core of a macrocyclic compound, has a lone pair of electrons available to donate to the Fe(III) center. For example, the pendant donor may be a nitrogen-containing group (e.g., amino, benzimidazole, imidazole, aniline, pyrazoyl, triazole, benzotriazole, etc.) or an oxygen-containing group (e.g., ketone, alcohol, alkoxide, amide, phosphonic acid, carboxylic acid, etc.). For example, some pendant donors, such as carboxylic acids, alcohols, imidazoles, and pyrazoles, may complex with Fe(III) or deprotonate at a specific pH. Such protonation and deprotonation forms are within the scope of this disclosure. For example, the pendant donor may be a phosphonate, phosphinate, phenolate, or oxide (e.g., alkoxide or phenoxide).

[0029] In certain embodiments, the macrocyclic compound has the following structure: [ka] Here, X1, X2, and X3 are N; Y1, Y2, or Y3 are each independently O-containing pendant donors, where O has at least one lone pair of electrons, preferably two or three lone pairs (e.g., ketones, alcohols, alkoxides, carboxylic acids, phosphinic acids, phosphonic acids, amides, phenols, or phenoxides, or deprotonated forms thereof, e.g., carboxylate ions, phosphinates, phosphonates, or oxides (including alkoxides or phenoxides); m1, m2, or m3 are each independently 0, 1, or 2 n1, n2, or n3 are each independently 1 or 2; R1 is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl group, and R1 is not substituted by the pendant donor, where the alkyl segments of the alkyl-Y chain (alkyl-Y1, alkyl-Y2, and / or alkyl-Y3) are each independently substituted (e.g., structure a or structure b) or unsubstituted. In structure a or b, the pendant may have either an R configuration or an S configuration at the chiral carbon: Scheme I [ka]

[0030] In one embodiment, the present disclosure provides a macrocyclic compound having the structure and definitions described herein.

[0031] Suitable macrocyclic compounds include the following: Scheme II [ka] Here, R1 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted heteroaryl group (e.g., pyridinyl, pyrazolyl, or imidazolyl), or a substituted or unsubstituted alkyl group, where the substituted or unsubstituted alkyl group is not a methyl group, and optionally, R1 is not a substituted pendant donor. For example, if the macrocyclic core has structure I, Z1 is either H or one of the pendant groups in scheme III, and Z2 and Z3 are each independently pendant groups (e.g., one of the pendant groups in scheme III); if the macrocyclic compound has structure II, Z1 and Z2 are each independently pendant groups (e.g., one of the pendant groups in scheme III).

[0032] The macrocyclic compound has at least two pendant donors on the macrocyclic core. For example, the pendant donors can have any one of the structures from Scheme III: Scheme III [ka] and their protonated, partially deprotonated, or fully deprotonated species (if applicable). Here, Q3, Q4, and Q5 are each independently anionic groups, or selected from the following: -H, -NR2, -NO2, -CN, -(CH2) m NR2, OH, OR, -CH2P(O)(OH)2, -(CH2) mP(O)(OH)2, -SO3H, and their deprotonated species, where m is 1 or 2, and R is H, an alkyl group (e.g., methyl, trifluoromethyl, etc.), an aryl group (e.g., a phenyl group, or a sulfonate-substituted phenyl group), an alkylcarboxylate group, an alkylcarboxylic acid group, etc. The compound has any two of 1, 1', 2, 3, 4, 8, 10, or a combination thereof. In various examples, the pendant donors are different (e.g., macrocyclic compounds have at least two different pendant donors). For example, some pendant donors, such as alcohols and phenol pendants, may deprotonate when complexed with Fe(III) or at certain pH values. Such forms of protonation and deprotonation are within the scope of this disclosure. For example, the pendant donor is an oxide (e.g., an alkoxide, a phenoxide, etc.).

[0033] In various non-limiting embodiments, if the macrocyclic core has structure I, then Z1 and Z2 are both 1, 1', 2, 3, 4, 8, 10, or any combination thereof, and R1 is selected from any one of the pendant groups 5, 6, 7, 9, 11, 12, 13, or 14 of scheme III.

[0034] Macrocyclic compounds may contain one or more auxiliary pendant groups. The auxiliary pendant groups (one or more) may be one or more coordination auxiliary pendant groups and / or one or more non-coordination auxiliary pendant groups.

[0035] Non-coordination auxiliary pendant groups do not have heteroatoms that can bond with Fe(III) metal ions to form 5-membered or 6-membered chelates. Non-limiting examples of non-coordination auxiliary pendant groups include benzyl groups, phenyl groups, and other aromatic (e.g., aryl) groups having one or more methylene groups bonded to the aromatic group, or not having a methylene group, and alkyl groups (both branched and linear). Other non-limiting examples of non-coordination auxiliary pendant groups include biphenyl, naphthyl, anthracenyl, pyridyl, quinolyl, methyl, ethyl, isopropyl, n-propyl, ethyl methoxy ether, and PEG derivatives (polyethylene glycol).

[0036] In various other examples, macrocyclic compounds have the following structure: [ka] Here, the tri(hydroxy)butyl group(s) and the -(CH2)nR group are pendant groups, where each R is independently selected from alkyl groups; aryl groups; heteroaryl groups; alkyl groups containing one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, etc., or combinations thereof; aryl groups containing one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, etc., or combinations thereof; heteroaryl groups containing one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, etc., or combinations thereof; and H. The R group may be substituted or unsubstituted. Each n is independently selected from 1, 2, or 3. The pendant group may have one or more chiral carbons.

[0037] Non-restrictive examples of pendant bases are as follows: [ka] and their protonated species, partially deprotonated species, and deprotonated species (where applicable). Here, Q3, Q4, and Q5 are each independently anionic groups, or -H, -NR2, -NO2, -CN, -(CH2) m NR2, OH, OR, -CH2PO(OH)2, -(CH2) m P(O)(OH)2, -SO3H, and their deprotonated species, partially deprotonated species, and protonated species (if applicable), where m is 1 or 2, or their partially or completely deprotonated analogs, where R is H, an alkyl group (e.g., methyl, trifluoromethyl, etc.), an aryl group (e.g., a phenyl group, or a sulfonate-substituted phenyl group), an alkylcarboxylate group, an alkylcarboxylic acid group, etc.

[0038] The Fe(III) complex may have bound water and hydroxide ligands, or it may not have bound water and hydroxide ligands.

[0039] In certain embodiments, an Fe(III) cation, which may be a high-spin Fe(III) cation, is complexed with a macrocyclic compound. In certain other embodiments, the Fe(III) cation is not complexed with a macrocyclic compound. Fe(III), which may be a high-spin Fe(III) cation, may be complexed with a macrocyclic compound as shown herein.

[0040] As previously mentioned, some pendant donors, such as alcohols and phenolic pendant groups, can be deprotonated when complexed with Fe(III). Their corresponding phenolate ions or oxides (e.g., alkoxides or phenoxides) are within the scope of this disclosure.

[0041] Non-limiting examples of coordinating pendant groups (e.g., additional pendant groups when two are already hydroxylpropyl) include oxygen or nitrogen donors that form five- or six-membered chelates (e.g., derivatives of amides, carboxylates, phosphinates, phosphonates, alcohols, phenols, or aminophenols). Some of these groups deprotonate when bonded to Fe(III).

[0042] A macrocyclic complex containing one or more non-coordinating auxiliary pendant groups may have an open coordination site (i.e., open coordination). A macrocyclic complex containing one or more coordinating auxiliary pendant groups may not have an open coordination site (i.e., closed coordination).

[0043] In various embodiments, Z1, Z2, and Z3 are each independently selected from the following: [ka] [ka] [ka] and their protonated, deprotonated, and partially deprotonated species (where applicable).

[0044] In one embodiment, the subject disclosure provides a macrocyclic compound having the structures and definitions set forth in Schemes II-III, wherein if the macrocyclic compound has structure I, then any or all of the following provisos apply: when Z1 and Z2 are structure 1, Z3 is not structure 1; when Z1 and Z2 are structure 1', Z3 is not structure 1'; when Z1 and Z2 are structure 2, Z3 is not structure 2; when Q1 and Q2 are H; when Z1 is H, Z2 is not structure 2.

[0045] In certain embodiments, the Fe(III) cation (which may be a high-spin Fe(III) cation) is complexed with a macrocyclic compound. In certain other embodiments, the Fe(III) cation is not complexed with a macrocyclic compound. Fe(III) (which may be a high-spin Fe(III) cation) may be complexed with a macrocyclic compound as shown herein.

[0046] As previously mentioned, some pendant donors, such as alcohols and phenolic pendants, may deprotonate upon complexation with Fe(III). Their corresponding phenolate ions or oxides (e.g., alkoxides or phenoxides) are within the scope of this disclosure.

[0047] In one embodiment, the present disclosure provides an Fe(III) complex comprising Fe(III) complexed with a polymer having the structure shown in Schemes II to III, as defined in Schemes II to III.

[0048] In another embodiment, the subject disclosure provides Fe(III) complexes comprising Fe(III) complexed with a polymer having the structures shown in Schemes II-III, as defined in Schemes II-III, where, if the polymer has structure I, any or all of the following provisos apply: when Z1 and Z2 are structure 1, Z3 is not structure 1; when Z1 and Z2 are structure 1', Z3 is not structure 1'; when Z1 and Z2 are structure 2, Z3 is not structure 2.

[0049] Generally, only one O donor atom coordinates to a metal ion, but certain types of pendants may have two or more O donor atoms (e.g., substituted alkylphenol pendants). The polyol may be an alkyl polyol, an aryl polyol, or a combination thereof.

[0050] Macrocyclic compounds can have various pendant groups or combinations of pendant groups. If there are two or more pendant donors, they may be the same or different.

[0051] In various examples, the macrocyclic core has three nitrogen atoms. In various examples, there are two carbon atoms separating the nitrogen atoms in the macrocyclic core. One or more carbon atoms in the macrocyclic core may be unsubstituted (e.g., -CH2-) or substituted (e.g., -CHR-, or -CRR'-, where R and R' are alkyl or aryl groups (e.g., benzyl groups) as described herein).

[0052] The pendant group can be covalently attached to the macrocyclic core (for example, via nitrogen). For example, the pendant group is covalently attached to the TACN(I) macrocyclic core.

[0053] Examples of macro-ring bodies in this disclosure include, but are not limited to, the following. [ka] [ka] And their protonated and deprotonated analogs.

[0054] Examples of chelated macrocyclic compounds include, but are not limited to, the following: [ka] [ka] [ka] and their protonated species, partially deprotonated species, and deprotonated species (if applicable).

[0055] Examples of Fe(III) complexes without intrinsic water, such as Fe(L6B), or examples of Fe(III) complexes with intrinsic water, such as Fe(L1B): [ka] In various examples, other hydroxyl groups of the following groups may coordinate to high-spin Fe(III): [ka]

[0056] Macrocyclic compounds can be macrocyclic ligands. The macrocyclic ligands described herein stabilize the trivalent iron (Fe(III)) state. The coordination geometry is designed for the preferred Fe(III) bond compared to Fe(II) to maintain the oxidized state of Fe(III) (e.g., under biologically appropriate conditions). Stabilization of the Fe(III) state also plays a role in suppressing the generation of reactive oxygen species that result from the reduction of the complex to the Fe(II) state.

[0057] It is desirable that the Fe(III) center is more stable than Fe(II) and does not react with biological reducing agents to generate reactive oxygen species (ROS). Such a redox-inert (under biological conditions) Fe(III) center has a low redox potential with respect to NHE. Examples of macrocyclic complexes of the present invention having a macrocyclic core and a pendant group that produce a stabilized Fe(III) include, but are not limited to, a 1,4,9-triazacyclononane macrocyclic core and an alcohol pendant group (which is deprotonated when Fe(III) is bonded).

[0058] In various examples, the macrocyclic compounds or compounds of the present disclosure are reduced to a reduction potential (E) of less than 0 mV (vs. normal hydrogen electrode (NHE)) in an aqueous solution at a biologically appropriate pH (e.g., pH 6.5–7.5 or 7.2–7.4, including all 0.1 pH values ​​and ranges in between). oIn various other examples, the macrocyclic compounds or compounds of the present disclosure exhibit a reduction potential (E) of at least 300mV, at least 250mV, at least 200mV, at least 150mV, at least 100mV, or at least 50mV, or at least 0mV, or at least -100, at least -150, at least -200, at least -300, at least -400, at least -500, or at least -600mV (vs. standard hydrogen electrode (NHE)) in an aqueous solution at a biologically appropriate pH (e.g., 6.5–7.5 or 7.2–7.4 pH (including all 0.1 pH values ​​and ranges in between). o In various other examples, the macrocyclic compounds or compounds of the present disclosure exhibit a reduction potential (E) less than 0 to -600 mV (vs. standard hydrogen electrode (NHE)) in aqueous solutions of a biologically appropriate pH (e.g., pH 6.5 to 7.5 or 7.2 to 7.4, including all 0.1 pH values ​​and ranges in between). o ) indicates.

[0059] The reduction of the T1 relaxation time of water protons by iron(III) complexes (T1 relaxation) is facilitated by both in-sphere and out-sphere water interactions, and by proton exchange via water ligands or hydroxyalkyl pendants. Therefore, in various examples, the macrocyclic complexes and compounds of the present disclosure include one or more pendant donor groups that can hydrogen-bond to water via heteroatoms such as oxygen or nitrogen. A non-limiting example of such pendant donor groups is a pendant alcohol group that deprotonates to an alkoxide group. Furthermore, in various examples, the macrocyclic compounds and compounds of the present disclosure include open coordination sites that can bond water. These water ligands may ionize at neutral pH to form hydroxide ligands, as demonstrated, for example, by pH-potentiometric titration.

[0060] The coordination chemistry of Fe(III) is coordination number dependent. The macrocyclic compounds of this disclosure have donor groups (also called macrocyclic donors) that may be part of the macrocyclic core, and donor groups (also called pendant donors) that may be part of substituents (e.g., pendant groups) on the macrocyclic core. When Fe(III) is complexed into the macrocyclic compounds of this disclosure, 4 to 6 donors are complexed into the metal ion center. In one embodiment, the macrocyclic core may have 2 to 3 donors and 2 to 3 pendant donors. In various embodiments, there are 2 macrocyclic donors and 3 pendant donors, 2 macrocyclic donors and 4 pendant donors, 3 macrocyclic donors and 2 pendant donors, 3 macrocyclic donors and 3 pendant donors, and 3 macrocyclic donors and 4 pendant donors.

[0061] Examples of suitable macro-annular cores with pendant donors include: [ka] [ka] [ka] [ka] [ka] Here, Fe(III) may be complexed in the core.

[0062] Examples of macrocyclic compounds (e.g., macrocyclic complexes) include, but are not limited to, the following: [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] and their deprotonated species, partially deprotonated species, and protonated species (if applicable).

[0063] In various embodiments, the macrocyclic compounds, macrocyclic complexes, or compounds of the Disclosure may be salts, partial salts, hydrates, polymorphs, or stereoisomers, or mixtures thereof. For example, the macrocyclic compounds, macrocyclic complexes, or compounds may exist as racemic mixtures, single enantiomers, single diastereomers, or mixtures of diastereomers. In certain embodiments, after complexation of a metal ion, the macrocyclic complex or compound may exist as a mixture of diastereomers and / or conformers (which can be determined by NMR). Diastereomers may arise from the conformation of the macrocyclic core and the orientation of substituents on the macrocyclic core.

[0064] The compounds of this disclosure may have intrinsic water or, instead, hydroxide ligands. In one embodiment, the compound has one intrinsic ligand (q) that contributes to relaxation, as shown in Formula 1.

number

[0065] Equation 1 shows that the relaxation capacity is influenced by contributions from bound water (innersphere, IS) and second-sphere (SS) water (outersphere). Equation 2 predicts that a larger number of bound water molecules and a faster ligand exchange rate constant (shorter bound water lifetime (τm)) are advantageous. Of note is the parameter r1, used to characterize the relaxation capacity, with units of mM. -1 s -1 And, T 1obs (s -1 This is obtained from a plot of ()-vs-contrast agent concentration. The number and residence time are not clearly defined, but a similar relationship exists for secondary sphere water as well.

[0066] The ratio of T1 to T2 relaxation abilities (R1 / R2) of the macrocyclic complex or compound of the Disclosure is preferably close to 1 (unity). By definition, the transverse relaxation ability, R2, is always greater than the longitudinal relaxation ability, R1. In various examples, the Fe(III) contrast agents of the Disclosure preferably have a low R2 such that the R1 / R2 ratio is close to 1. In various examples, the macrocyclic complex or compound of the Disclosure has an R1 / R2 ratio of 0.5 to 0.2 or 0.8 to 0.6.

[0067] Iron(III) complexes may have desirable interactions with water molecules that can promote the relaxation of water protons. While not intended to be bound by any particular theory, exchange between intrinsic water and bulk water is considered a key mechanism for proton relaxation. However, interactions with secondary spheric water may also contribute. Proton exchange of pendants with OH protons derived from hydroxyalkyl groups provides an additional mechanism.

[0068] This suggests that optimizing the interaction between the Fe(III) complex and water molecules is important for increasing the proton relaxation of water. While not intended to be theoretically bound, the exchange of intrinsic water and bulk water is considered the dominant mechanism for proton relaxation in Gd(III) complexes. However, Fe(III) is a much smaller metal ion than Gd(III) (0.78 Å vs 1.25 Å, respectively). The shorter MH distance of bound water in Fe(III) compared to Gd(III) suggests that the relative efficiencies of the second sphere and exosphere-to-intrinsic sphere contributions may differ between these two metal ion complexes.

[0069] Related paramagnetic relaxation of water (1 / T 1m There are three mechanisms that contribute to longitudinal relaxation: scalar (contact) contribution, dipole-dipole contribution, and Curie spin relaxation. Of these, the most important in the longitudinal relaxation considered here is the dipole-dipole contribution (1 / T1DD). For electric field strengths of 1.5T or higher, 1 / T1DD is defined as shown in Equation 3 (where S is the spin quantum number, ω H r is the Larmor frequency of protons. MH γ is the distance between the metal ion and the proton. H is the proton gyromagnetic ratio, ge is the electron g factor, μ B This is the Bohr magneton, μ o (where is the permittivity of vacuum). Of note, the 1 / T1DD term increases as the total spin (S) increases (higher relaxation ability), which is more favorable to Gd(III) than to Fe(III). However, the distance from the paramagnetic Fe(III) center to the water proton (r MH ) is short, especially 1 / r 6 Considering the dependence, Fe(III) proton relaxation is favorable.

number

[0070] The correlation time (τc) of the dipole relaxation mechanism is equal to the lifetime of bound water (1 / τm ), rotational motion of contrast agent (1 / τR ), and longitudinal relaxation of unpaired electrons (1 / T 1eIt is affected by various processes, including ). While all three of these processes can contribute, their importance depends on the magnetic field strength. Much of the literature focuses on the importance of these processes at low magnetic field strengths (<1 T). Under such conditions, rotational processes or electron relaxation times may be limiting, and τm is 10 ns (k ex =10 8 s -1 It should be within a narrow range close to ). However, simulations have shown that at higher magnetic field strengths (≧1.5 T), the optimal τm should have a wider range (1~100 ns), and the rotational motion should be intermediate between that of small molecules and proteins. An important parameter is the electron relaxation time, T. 1e This is the case for Fe(III) T 1e The long duration is thought to be due to the complex having high symmetry, minimal zero-field splitting, and slow relaxation of the electronic state. Furthermore, the coordination sphere needs to prioritize high-spin (S=5 / 2) rather than low-spin (S=1 / 2).

[0071] The macrocyclic compounds of the present disclosure are thermodynamically stable and / or kinetically inert to dissociation. In one embodiment, the macrocyclic compound is thermodynamically stable and kinetically inert to dissociation. In one embodiment, the kinetic inertness of the macrocyclic compounds of the present disclosure can be described using the rate constant of dissociation. In one embodiment, the macrocyclic donor and pendant donor do not significantly dissociate from the metal center for up to 24 hours at neutral pH in the presence of 1) 25 mM carbonate, 0.40 mM phosphate, 100 mM NaCl, pH 7.2; 2) pH 4, 100 mM NaCl (e.g., dissociation of less than 1%, less than 0.1%, or less than 0.01% is observed).

[0072] In one embodiment, Fe(III) is high-spin S=5 / 2. A paramagnetic spin state is required for effective T1 (longitudinal) relaxation. To maintain Fe(III) in a high-spin state, the ligand (or crystal) magnetic field splitting must not be too large. If the crystal field splitting is greater than the pair formation energy, it will be in a low-spin (S=1 / 2) state. Fe(III) can be easily maintained in a high-spin paramagnetic state by various ligand donor groups (particularly including anionic oxygen donors).

[0073] The Fe(III) complex may have an open coordination site for a water ligand, two alcohol pendants, and a third pendant. Auxiliary pendant groups such as aryl groups (e.g., benzyl and substituted benzyl groups, e.g., methoxy-benzyl, fused ring aryl groups, etc.) or alkyl groups (e.g., branched alkyl groups such as methyl, ethyl, or isopropyl) are particularly effective. The relaxation ability of a coordinationally saturated complex can be improved by adding larger auxiliary pendants to slow the rotational correlation time. The third pendant group may be used to close the coordination sphere around Fe(III), and anionic groups have their pK a By adjusting the value, proton exchange of hydroxylalkyl groups can be promoted.

[0074] The electron relaxation time for high-spin Fe(III) centers is sufficiently long (for example, 3 × 10⁻¹⁰ -11 (T) It is desirable that the correlation time constant expressed by Equation 4 does not become a limiting factor at magnetic field strengths of 1.5 Tesla or higher. This can be achieved, for example, by using macrocyclic ligands that provide high symmetry to the Fe(III) center. In high-spin Fe(III) complexes of axially strained complexes, (T 1e ) -1 is D 2 Since it is directly proportional to this, a small zero-field division coefficient (D) is desirable.

[0075] It is desirable that the Fe(III) complex remains in a trivalent oxidized state and is not reduced, for example, by peroxides, superoxides, ascorbic acid, or by the concentrations of glutathione present in the extracellular culture medium of cells (e.g., mammalian cells (e.g., human cells)). Typically, a redox potential less than 200 mV (<200 mV) relative to NHE is sufficient.

[0076] For use in the methods of this disclosure, the compounds described herein can be administered as pharmaceutical formulations. Accordingly, they can be provided in various compositions and can be combined with one or more pharmaceutically acceptable carriers. Some examples of pharmaceutically acceptable carriers are described in "Remington: The Science and Practice of Pharmacy (2012) 22nd Edition, Philadelphia, PA. Lippincott Williams & Wilkins." The compositions can be provided as liquids, solutions, or solids and can be combined with any suitable delivery form or vehicle, including, but not limited to, caplets, capsules, tablets, inhalants, and aerosols.

[0077] The composition may contain one or more standard pharmaceutically acceptable carriers. Non-limiting examples of compositions include solutions, suspensions, and emulsions. Non-limiting examples of diluents include distilled water for injection, physiological saline, vegetable oils, alcohols, and combinations thereof. Furthermore, the injectable preparation may contain stabilizers, solubilizers, suspending agents, emulsifiers, analgesics, buffers, preservatives, and the like. The composition may be formulated into a sterile solid preparation (e.g., by lyophilization), used after sterilization, or dissolved in sterile water for injection or other sterile diluents (one or more) immediately before use. Non-limiting examples of pharmaceutically acceptable carriers are described in "Remington: The Science and Practice of Pharmacy (2012) 22nd Edition, Philadelphia, PA. Lippincott Williams & Wilkins".

[0078] Acceptable carriers, excipients, or stabilizers are non-toxic to the recipient at the dose and concentration used and include, but are not limited to, the following: buffers such as phosphates, citrates, histidine, and other organic acids; antioxidants (including, but not limited to, ascorbic acid and methionine); preservatives (e.g., octadecyldimethylbenzylammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl, or benzyl alcohol; alkylparabens such as methylparaben or propylparaben; catechol; resorcinol; cyclohe Xanol; 3-pentanol; and m-cresol; low molecular weight (less than approximately 10 residues) polypeptides; proteins such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates such as glucose, mannose, or dextrin; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose, or sorbitol; salt-forming counterions such as sodium; metal complexes (e.g., Zn-protein complexes); and / or TWEEN TM PLURONICS TM , nonionic surfactants such as polyethylene glycol (PEG). In one embodiment, the pharmaceutical composition may include, but is not limited to, sucrose, polysorbate 20, NaCl, KCl, sodium acetate, sodium phosphate, arginine, lysine, trehalose, glycerol, and maltose, as buffering and stabilizer components.

[0079] Various methods known to those skilled in the art may be used to introduce the compositions of this disclosure into an organism. These methods include, but are not limited to, intravenous, intramuscular, intracranial, intrathecal, intradermal, subcutaneous, and oral routes. In several embodiments, the compositions are administered intravenously.

[0080] The required solubility of a complex depends on its contrast-producing effect. For Fe(III) T1 contrast agents with good relaxing ability, a concentration of 5 mM to 100 mM of the complex is required. However, solubility and / or relaxing ability can also be increased using other additives such as human serum albumin (HSA) or meglumine. Adding HSA (e.g., 35 mg / mL) to some Fe(III) complexes yields higher T1 relaxing ability. Solubility is generally measured in aqueous solution at a near-neutral pH (e.g., 6.5 to 7.5: including all 0.1 pH values ​​and ranges in between) in 100 mM NaCl containing 25 mM carbonate and 0.4 mM phosphate. The dose of the composition used inevitably depends on the needs of the individual to whom the composition of this disclosure is administered. These factors include, but are not limited to, the individual's body weight, age, sex, and medical history.

[0081] In one embodiment, the present disclosure provides imaging methods using macrocyclic complexes and compounds described herein. The imaging methods utilize magnetic resonance imaging. Non-limiting examples of such methods include magnetic resonance imaging (MRI).

[0082] Specifically, the macrocyclic compounds disclosed herein are complexed with Fe(III) and can be used as T1 MRI contrast agents. These complexes may have properties that change with pH. Such properties make these complexes useful for pH mapping (for example, to enable better treatment for diseases such as cancer, stroke, and heart disease).

[0083] The imaging methods of this disclosure can be used to image cells, tissues, organs, vascular systems (vascular structures), or parts thereof. The cells, tissues, organs, and vascular systems may be part of an individual. "Individual" means a human or a non-human animal (e.g., a cow, a pig, a mouse, a rat, a cat, a dog, or other farm animal, pet, or service animal). In one embodiment, this disclosure provides a method for obtaining an image of at least a part of a cell, tissue, organ, or vascular system, comprising the steps of contacting the cell, tissue, organ, or vascular system with a compound of this disclosure, and imaging at least a part of the cell, tissue, organ, or vascular system to obtain an image of the cell, tissue, organ, or vascular system. At least a part of the cell, tissue, or organ may be alive or dead. Similarly, the individual may be alive or dead.

[0084] This administration may be carried out by various delivery methods. The compound or composition may be administered systemically. As used herein, the term "systemically" includes parenteral administration, topical administration, oral administration, spray inhalation, rectal administration, nasal administration, and buccal administration. As used herein, the term "parenteral" includes subcutaneous administration, intravenous administration, intramuscular administration, intra-articular administration, intrasynovial administration, intrasternal administration, intrathecal administration, intrahepatic administration, intrafocal administration, and intracranial administration.

[0085] In one embodiment, a macrocyclic complex compound is used as an Fe(III)T1 MRI contrast agent. This contrast is generated by T1-weighted imaging, which provides positive contrast to the region where the iron complex accumulates. The complex is high-spin Fe(III) under biologically reducing conditions and has inosphere and / or exosphere water interactions that result in a reduction of the T1 relaxation time of bulk water protons.

[0086] The macrocyclic compounds disclosed herein can be prepared, for example, as described herein.

[0087] The following embodiments are provided to illustrate the present disclosure. They are not intended to limit the scope in any way. Those skilled in the art will recognize that routine modifications can be made to these embodiments, and these are intended to be within the scope of the present disclosure.

[0088] [Further explanation of this disclosure] In a particular embodiment, the macrocyclic compound has the following structure: [ka] Here, X1, X2, X 3、 And X4 is N; Y1, Y2, Y3 and Y4 are each independently either a pendant donor containing N (where N has a lone pair of electrons (e.g., amino, benzimidazole, imidazole, aniline, pyrazoyl, triazole, benzotriazole, etc.)) or a pendant donor containing O (where O has at least one lone pair of electrons, preferably two or three lone pairs of electrons (e.g., ketones, alcohols, alkoxides, carboxylic acids, amides, phenols or phenoxides, or deprotonated forms thereof, e.g., carboxylate ions, imidazolate ions, pyrazolate ions, or oxides containing alkoxides or phenoxides); m1, m2, m3, m4 is independently 0, 1, or 2; n1, n2, n3, and n4 are independently 1 or 2; R1, R2, and R3 are independently a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, where R1, R2, and R3 are unsubstituted by the pendant donor, where the alkyl segments of the alkyl-Y chain (alkyl-Y1, alkyl-Y2, alkyl-Y3, and / or alkyl-Y4) are independently substituted (e.g., structure a or structure b) or unsubstituted (structure c or structure d). For structures a-f, the pendant may have either an R or S configuration at the chiral carbon: [ka]

[0089] In some embodiments, the macro-ring can have a structure (Scheme IV): Scheme IV [ka] Hereinafter, R1 is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl; where, if the macrocyclic structure has structure I, Z1 is H or one of the pendant groups of scheme V, and Z2 and Z3 are each independently one of the pendant groups of scheme V; where, for structures I and II, Z1, Z2, and Z3 are each selected independently of each other as applicable. Hereafter, this paragraph will be referred to as "scheme IV".

[0090] A macrocyclic compound has at least one pendant donor on its macrocyclic core. For example, the pendant donor may have the following structure: Scheme IX [ka] Here, R is methyl, Q1 and Q2 are independently -H, -OCH3, -CO2H, or -CH2CO2G4, and G4 is H, C1~C 12 A linear or branched substituted or unsubstituted alkyl group, or a PEG group (-CH2CH2O-) n (n=1~12, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12), and Q3 is H, linear or branched C1~C 12 A substituted or unsubstituted alkyl group, or a PEG group (-CH2CH2O-) n(n = 1 to 12, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12), and Q4 and Q5 are each independently -H, -OCH3, -CO2H, or a substituted or unsubstituted alkyl group having a linear or branched structure, and A is a substituted or unsubstituted alkyl group having a linear or branched structure of C1 to C 12 which is a substituted or unsubstituted alkyl group having a linear or branched structure, or a substituted or unsubstituted aryl group, or a naturally occurring amino acid (e.g., glycine) or a synthetic amino acid or an analog thereof. For example, some pendant donors such as carboxylic acid, alcohol, imidazole, pyrazole, etc. may complex with Fe(III) or deprotonate at a specific pH value. Such protonated and deprotonated forms are within the scope of the present disclosure. For example, the pendant donor is a carboxylate ion, imidazolylate ion, pyrazolate ion, or an oxide (e.g., alkoxide or phenoxide).

[0091] In one embodiment, the present disclosure provides a macrocyclic compound having the structures and definitions described herein, based on the following scheme and with the following provisos: Scheme VIII:

Chemical formula

[0092] In one embodiment, the disclosure provides a macrocyclic compound having the structures and definitions defined in Schemes IV, VIII, and IX, wherein if the macrocyclic compound has structure I, then any or all of the following provisos apply: when Z1=Z2=structure 1, Z3≠structure 1; when Z1=Z2=structure 2, Z3≠structure 2; when Z1=Z2=structure 3, Z3≠structure 3; when Z1=Z2=structure 6, Z3≠structure 6 ;When Z1=Z2=structure 7, Z3≠structure 7;When Z1=Z2=structure 9, Z3≠structure 9;When Z1=Z2=structure 11, Z3≠structure 11;When Z1=Z2=structure 12, Z3≠structure 12;When Z1=Z2=structure 13, when Q1=Q2=H, Z3≠structure 13, when Q1=Q2=H;When Z1=Z2=structure 15, Z3≠structure 15;At most two of Z1, Z2, or Z3 = structure 16, i) Q4=Q5=t-butyl, ii) Q4=Q5=OCH 3、 iii) Q4=t-butyl and Q5=OCH3, or iv) Q4=OCH 3、 And when Q5 = t-butyl; when Z1 = H, Z2 ≠ structure 1; when Z1 = H, Z2 ≠ structure 7; when Z1 = H, Z2 ≠ structure 9; when Z1 = H, Z2 ≠ structure 13; when Z1 = Z2 = structure 1, Z3 ≠ structure 15; when Z1 = structure 1 and Z2 = H, Z3 ≠ structure 16, when Q = t-butyl; here, if the macrocyclic body has structure III, any or all of the following provisos apply: when Z1 = structure 1, Z2 ≠ structure 1; when Z1 = structure 17, Z2 ≠ structure 17.

[0093] In some embodiments, when the macrocyclic body of scheme IV is complexed with Fe(III), R1 does not coordinate to Fe(III).

[0094] In one embodiment, a macro-annular body defined according to scheme IV has at least one pendant donor on the macro-annular core. For example, the pendant donor may have the following structure (scheme V). Scheme V: [ka] Here, R2 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group (which may be an aryl group), or a substituted ether; R3 is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group; and R4 is a substituted alkyl group (e.g., substituted with a hydroxyl group or a carboxylate group), an unsubstituted alkyl group, or a substituted or unsubstituted aryl group. For example, some pendant donors, such as alcohols, phosphinic acids, phosphonic acids, or sulfonic acids, may be deprotonated when complexed with Fe(III) or at certain pH values. Such forms of protonation and deprotonation are within the scope of this disclosure. For example, the pendant donor may be an alkoxide, phosphinate, phosphonate, or sulfonate, as shown in Scheme VI. Scheme VI (Ionization Group): [ka]

[0095] In certain embodiments, the R1 group of the macrocyclic material in schemes I and II (which may be a coordinating auxiliary or a non-coordinating auxiliary) may have the structure according to scheme VII. Scheme VII [ka] Here, A and A' are, independently, substituted or unsubstituted C1-C with linear or branched structures. 12Q1 is an alkyl group or proton, where Q1 is an aryl group substituted with an anionic group (e.g., carboxylate, sulfonate, phosphonate, phosphate ester, or phosphinate), an alkyl group substituted with an anionic group (e.g., carboxylate, sulfonate, phosphonate, phosphate ester, or phosphinate), or an aralkyl group substituted with an anionic group (e.g., carboxylate, sulfonate, phosphonate, phosphate ester, or phosphinate); where at least one of A or A' is an alkyl group substituted with an anionic group (e.g., an amino acid, particularly glycine, serine, or aspartic acid).

[0096] In some embodiments, if the macrocyclic structure has the structure of scheme IV (I) and Z1 and Z2 are structure 6 of scheme V (where R3 is unsubstituted ethyl), then Z3 is not structure 6 of scheme V (where R3 is an unsubstituted ethyl group). In further embodiments, if the macrocyclic structure has the structure of scheme II (I) and Z1 and Z2 are structure 6 of scheme V (where R3 is unsubstituted or substituted ethyl), then Z3 is not structure 6 of scheme V (where R3 is an unsubstituted or substituted ethyl group). In additional embodiments, if the macrocyclic structure has the structure of scheme IV (I) and Z1 and Z2 are structure 6 of scheme V (where R3 is an unsubstituted alkyl), then Z3 is not structure 6 of scheme V (where R3 is an unsubstituted alkyl). In yet another embodiment, the macrocyclic body has structure (I) of scheme IV, and Z1 and Z2 have structure 6 of scheme V (where R3 is unsubstituted or substituted alkyl), but Z3 does not have structure 6 of scheme V (where R3 is unsubstituted or substituted alkyl).

[0097] In a particular embodiment, if the macro-ring has structure (I) of scheme IV, and Z1 and Z2 have structure 7 of scheme V, then Z3 does not have structure 7 of scheme V.

[0098] In certain embodiments, if the macrocyclic structure has the structure of scheme IV (I) and Z1 and Z2 have the structure of scheme V (where R3 is an alkyl with a terminal hydroxyl substitution), then Z3 does not have the structure of scheme V (where R3 is an alkyl with a terminal hydroxyl substitution). In further embodiments, if the macrocyclic structure has the structure of scheme IV (I) and Z1 and Z2 have the structure of scheme V (where R3 is a substituted alkyl), then Z3 does not have the structure of scheme V (where R3 is a substituted alkyl).

[0099] In some embodiments, if the macrocyclic structure has the structure of scheme IV (II), Z1 and Z2 are the structure of scheme V (8), and R4 is an alkyl with a terminal hydroxyl substitution, then R1 is not an alkyl with a terminal aryl group. In further embodiments, if the macrocyclic structure has the structure of scheme IV (II), Z1 and Z2 are the structure of scheme V (8), and R4 is an alkyl with a terminal hydroxyl substitution, then R1 is not a substituted alkyl.

[0100] In various examples, a macrocyclic core with a pendant donor does not have the following structure: [ka] [ka] [ka] [ka] [ka] [ka] Here, Fe(III) may be complexed with these compounds.

[0101] In various examples, the complexes of this disclosure do not have the following structure: [ka]

[0102] In various examples, the macrocyclic core has the following structure: [ka]

[0103] In certain embodiments, the complex used in the method of this disclosure may have the following structure: [ka]

[0104] U.S. Patent No. 11,261,208 and U.S. Patent Application No. 16 / 973,349 are incorporated herein by reference.

[0105] The following statements describe various examples of macrocyclic compounds, macrocyclic complexes, compounds, and compositions of the present disclosure, as well as their uses: Statement 1. A macrocyclic compound of the present disclosure comprising a macrocyclic core (for example, a macrocyclic core comprising nine skeletal atoms, three of which are nitrogen atoms, at least two carbon atoms separating the nitrogen atoms, and one or more pendant groups of the present disclosure, wherein the one or more pendant groups are substituents on the macrocyclic core (for example, covalently bonded to the macrocyclic core) having the following structure: Scheme III: [ka] and their protonated, partially deprotonated, or fully deprotonated species (if applicable) Here, Q3, Q4, and Q5 are each independently anionic groups, or -H, -NR2, -NO2, -CN, -(CH2) mNR2, OH, OR, -CH2P(O)(OH)2, -(CH2) m Selected from P(O)(OH)2, -SO3H, and their deprotonated species, where m is 1 or 2. Here, R can be H, an alkyl group (e.g., methyl, trifluoromethyl, etc.), an aryl group (e.g., a phenyl group, or a phenyl group substituted with a sulfonate, etc.), an alkylcarboxylate group, an alkylcarboxylic acid group, etc. The compound has two of 1, 1', 2, 3, 4, 8, or 10, or a combination thereof. Statement 2. A macrocyclic complex comprising a macrocyclic core that is a macrocyclic compound of the present disclosure (e.g., the macrocyclic compound described in Statement 1) and / or a high-spin Fe(III) cation complexed to at least one pendant group substituent of the macrocyclic compound, or a salt, partial salt, hydrate, polymorph, or stereoisomer thereof, wherein the macrocyclic compound may exhibit a negative redox potential (e.g., a redox potential of less than 200 in an aqueous solution (e.g., water) at a biologically appropriate pH (e.g., 6.5–7.5 or 7.2–7.4) (vs. standard hydrogen electrode (NHE))). Statement 3. The macrocyclic compound or complex according to statement 1 or 2, wherein at least one or all of one or more pendant groups are covalently bonded to N on a macrocyclic core. Statement 4. The macrocyclic complex according to statement 2 or 3, wherein the macrocyclic complex has at least one open coordination site. In various examples, the macrocyclic complex is coordinationally saturated and has no water-binding sites. Statement 5. The macrocyclic complex according to any one of statements 2 to 4, wherein the macrocyclic complex has at least one water or at least one hydroxide complexed with a high-spin Fe(III) cation. Statement 6. A macrocyclic compound or macrocyclic complex according to any one of statements 1 to 5, wherein at least one of the pendant groups is substituted at the benzyl position or with any carbon of an alkyl group linked to a heteroatom of the pendant group. Statement 7. A macrocyclic compound or macrocyclic complex according to any one of statements 1 to 6, wherein the macrocyclic core is a TACN group. Statement 8. The macrocyclic complex according to any one of statements 2 to 4, wherein the macrocyclic complex comprises a TACN group and at least one (e.g., one or two) anionic pendant groups. Statement 9. The macrocyclic complex as described in Statement 8, wherein the anionic pendant is individually selected from alkoxide pendants, phenoxide pendants, phosphinate pendants, phosphonate pendants, and combinations thereof. In various examples, there are two hydroxyalkyl pendant groups or two phenoxide pendant groups. Statement 10. The macrocyclic complex according to statement 8 or 9, further comprising a coordinating pendant group or a non-coordinating pendant group. Statement 11. A macrocyclic compound or macrocyclic complex according to any one of statements 1 to 10, wherein the macrocyclic core has one of the following structures: [ka] Here, X1, X2, and X3 are N; Y1, Y2, or Y3 are each independently O-containing pendant donors, where O has at least one lone pair of electrons, preferably two or three lone pairs (e.g., ketones, alcohols, alkoxides, carboxylic acids, amides, phenols or phenoxides, or deprotonated forms of the aforementioned, e.g., carboxylate ions, or oxides (including alkoxides or phenoxides); m1, m2, or m3 are each independently 0, 1, or 2; n1, n2, or n3 is independently 1 or 2; R1 is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl group, where R1 is not substituted by the pendant donor, where the alkyl segments of the alkyl-Y chain (alkyl-Y1, alkyl-Y2, and / or alkyl-Y3) are independently substituted (e.g., structure a or structure b) or unsubstituted. In structure a or b, the pendant may have either an R or S configuration at the chiral carbon: Scheme I [ka] Statement 12. The macrocyclic compound or complex described in any one of statements 2 to 11, wherein the macrocyclic core has the following structure: Scheme II [ka] Here, R1 is a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, where R1 is not substituted by a pendant donor; and if the macrocyclic core has structure I, Z1 is H or one of the pendant groups of scheme III, and Z2 and Z3 are each independently a pendant group (e.g., one of the pendant groups of scheme III); and if the macrocyclic compound has structure II, Z1 and Z2 are each independently a pendant group (e.g., one of the pendant groups of scheme III). Statement 13. A macrocyclic complex according to any one of statements 2 to 12, wherein the macrocyclic core having a pendant donor has the following structure (to which Fe(III) may be complexed): [ka] [ka] [ka] [ka] Or, their deprotonated or partially deprotonated species, or their analogs, Alternatively, macrocyclic complexes have the following structure: [ka] [ka] [ka] Or, their deprotonated or partially deprotonated species, or their analogues. Statement 15. A composition comprising one or more macrocyclic compounds and / or one or more macrocyclic complexes of the present disclosure (e.g., one or more macrocyclic compounds described in Statement 1 and / or one or more macrocyclic complexes described in any one of Statements 2 to 14), and a pharmaceutically acceptable carrier. Statement 16. The composition according to Statement 15, further comprising human serum albumin and / or meglumine. Statement 17. A method for obtaining an image of at least a part of a cell, an organ, a vascular system, or a tissue, comprising: Contacting the cell, organ, vascular system, or tissue with one or more macrocyclic compounds and / or one or more macrocyclic complexes of the present disclosure (e.g., one or more macrocyclic compounds described in Statement 1 and / or one or more macrocyclic complexes described in any one of Statements 2 to 14), and / or one or more compositions of the present disclosure (e.g., the composition described in any one of Statements 15 to 16), and Imaging at least a part of the cell, organ, vascular system, or tissue to obtain an image of a part of the cell, organ, vascular system, or tissue (where the image is obtained using magnetic resonance). The method comprising the above steps. Statement 18. The method according to Statement 17, wherein the cell, organ, vascular system, or tissue is part of an individual. Statement 19. The method according to Statement 17 or 18, wherein the image is obtained using magnetic resonance imaging (MRI). Statement 20. The method according to any one of Statements 17 to 19, wherein the macrocyclic compound(s) and / or compound(s) is / are T1 agent(s). Statement 21. A macrocyclic core containing 9 skeletal atoms, wherein 3 atoms in the macrocyclic core are N atoms, at least 2 carbon atoms separate the N atoms, and one or more of the following pendant groups are substituents on the macrocyclic core: Scheme III

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0106] The following embodiments are provided to illustrate the present disclosure. The embodiments are not intended to limit the scope in any way. [Example 1]

[0107] The following examples describe methods for using the compounds of this disclosure.

[0108] The following complexes exhibit desirable solubility, at approximately 1.5 mM at 1.4 Tesla, 33°C, and neutral pH. -1 s -1 It demonstrated r1 relaxation ability and was tolerable when injected into mice at 50 umol / kg. MRI scans showed desirable T1-weighted contrast (4.7 Tesla): [ka] [Example 2]

[0109] The following examples illustrate the details of the synthesis of macrocyclic complexes and compounds of the present disclosure. [ka]

[0110] TOP(R=H) or TOP-Me(R=OCH) 3 ) synthesis 1,4,7-Triazacyclononane (1.0 g, 7.74 mmol) was dissolved in 40.0 mL of MeOH and stirred in a 100 mL round-bottom flask under Ar(g) conditions. Acetic acid (0.222 mL, 3.87 mmol) was added to the solution, followed by an aldehyde (0.421 mL, 3.87 mmol of salicylaldehyde, or 0.493 mL, 3.87 mmol of 5-methoxysalicylic acid). The reaction was stirred for 4–6 hours until imine formation was complete (monitored by TLC / ESI-MS). Then, solid sodium borohydride (0.366 g, 9.68 mmol) was slowly added to the solution. After 1 hour, the reaction was quenched with 40.0 mL of H2O. The MeOH was then removed under vacuum, and the pH of the aqueous solution was raised to 10 using 1 M NaOH solution. The crude product was extracted with chloroform (3 × 80 mL), and the combined organic layer was dried over anhydrous sodium sulfate and then dried under vacuum. The crude product was used without purification. The crude product was dissolved in 20.0 mL of ethyl OH and stirred in a 25 mL round-bottom flask. (s)-(-)propylene oxide (0.812 mL, 11.61 mmol) was added to the solution, and the reaction was monitored using ESI-MS until completion. The product was purified with silica resin (100% ethyl acetate → 8:2:1 ethyl acetate:methanol:10% ammonium hydroxide aqueous solution) and isolated as an oily substance. [R=H, brown oil, 559 mg, R=OCH3, 28.4 mg] ESI-MS(m / z): R = H, 352.42 (100), 410.38 (5). R=OCH3, 382.91 (100), 440.62 (10). [ka]

[0111] Synthesis of Fe(TOP) or Fe(TOP-Me) as described above TACN phenol ligand (0.142 mmol -R=H, 0.05 g, R=OCH3, 0.054 g) was dissolved in 4.0 mL of EtOH and heated to 70°C. Iron(II) chloride tetrahydrate (0.142 mmol, 0.029 g) dissolved in 1.0 mL of EtOH was slowly added to the ligand solution. Alternatively, FeCl3 was added to form an iron complex. After completion (monitored by ESI-MS), the solution was cooled to room temperature and reduced in volume to 2.0 mL, and then diethyl ether was slowly added until the iron complex precipitated (approximately 10.0 mL). The complex was filtered, washed with diethyl ether, and dried under vacuum. The iron complex was isolated as a purple solid. Yield approximately 50% (approximately 0.034 g). ESI-MS(m / z): R=H, 478.23 (100), R=OCH3, 508.26 (100).μ eff = 6.16 ± 0.3.

[0112] The L12 pendant was synthesized and prepared according to methods known in the art. [ka]

[0113] L12 Synthesis Dissolve DACO (1,4-bis(2-hydroxypropyl)-1,4,7-triazacyclononane) in 2-3 mL of pyridine and heat to 40°C. Add pendant precursor (ii) in 2-3 mL of pyridine to the heated DACO solution. Stir the reaction mixture at 40°C for 2-3 days. After the reaction is complete, remove the solvent under reduced pressure and dissolve in diethyl ether. Purify the product using a silica gel column with a diethyl ether:methanol gradient. Elute the product with 95% diethyl ether and 5% methanol. Mass spectrum m / z = 561 [ka]

[0114] Dissolve the product purified in the previous step in a 50% pyridine aqueous solution and heat to 70°C. Stir the reaction mixture for 1-2 days, or until the ethyl protecting group is completely removed. m / z = 533.8 [ka]

[0115] Synthesis of Fe(L12) Dissolve the deprotection ligand in 2-3 mL of ethanol and heat to 60°C. Slowly add 1 equivalent of iron(II) bromide in 2-3 mL of ethanol. Once the iron salt has been added, stir the solution at 60°C for 8 hours. [ka]

[0116] L13 Synthesis Quoted from literature [ka]

[0117] Dissolve DACO and precursor (iii) in a small amount of chloroform and add to acetonitrile. Stir the solution overnight at room temperature. Remove the solvent under reduced pressure and purify using a silica gel column. Elute the protected product with 99% DCM 1% methanol. [ka]

[0118] Dissolve the purified product in the minimum amount of methylene chloride. Add 7 equivalents of bromotrimethylsilane and reflux the solution for 18 hours. [ka]

[0119] Dissolve the deprotection ligand (L13) in 2-3 mL of ethanol and heat to 60°C. Slowly add 1 equivalent of iron(II) bromide in 2-3 mL of ethanol. After the addition of the iron salt is complete, stir the solution at 60°C for 8 hours. [ka] [Example 3]

[0120] The following examples illustrate the details of the synthesis of macrocyclic complexes and compounds of the present disclosure. [ka] [Example 4]

[0121] The following examples illustrate the details of the synthesis of macrocyclic complexes and compounds of the present disclosure.

[0122] Synthesis of Fe(III)-coordinated 2,2'-((1,4,7-triazonane-1,4-diyl)bis(methylene))diphenol. [ka] 1,4,7-Triazacyclononane (7.8 mmol) was dissolved in acetonitrile (35 mL) and placed on a stirring plate. Salicylaldehyde (19.2 mmol, 2.45 equivalents) was dissolved in another 35 mL of acetonitrile and placed in an addition funnel. The salicylaldehyde solution was added dropwise to 1,4,7-triazacyclononane (one drop approximately every 25 seconds). After the addition was complete, the mixture was stirred at room temperature for 18 hours. After 18 hours, sodium borohydride (39.1 mmol, 5 equivalents) was slowly added. As sodium borohydride was added, the product formed as a white solid and precipitated from the solution. This solid was recovered by vacuum filtration and recrystallized by heating from a mixture of methanol and acetonitrile to obtain a white solid. MS-ESI + 342.7 (M+H + , 100%). 1¹H NMR (300 MHz, D2O): 2.94 (4H, CH2, TACN), 3.27 (8H, CH2, TACN), 3.92 (CH2, N-CH2-phenol), 6.81 (4H, CH, phenol), 7.16 (CH, phenol). [ka] 2,2'-((1,4,7-triazacyclononane-1,4-diyl)bis(methylene))diphenol (0.3 mmol) was dissolved in 5 mL of methanol and stirred at 70°C. Iron(II) bromide (0.3 mmol) was dissolved in 5 mL of methanol. After the ligand solution reached 70°C, the iron solution was added dropwise. The mixture was stirred overnight, and then its volume was reduced to 2-3 mL using a rotary evaporator. When this solution was added dropwise to a stirred solution of diethyl ether, a reddish-purple solid was formed, which was collected and washed with diethyl ether. MS-ESI + 395.20 (M+H + , 100%). μ eff = 5.96 (Evans method)

[0123] Synthesis of (S)-2,2'-((7-(2-hydroxypropyl)-1,4,7-triazonan-1,4-diyl)bis(methylene))diphenol, to which Fe(III) is chelated. [ka] 2,2'-((1,4,7-triazacyclononane-1,4-diyl)bis(methylene))diphenol was synthesized as described above. The first ligand (0.1 mmol) was dissolved in 10 mL of methanol, and S-(-)propylene oxide (0.21 mmol, 2 equivalents) was added. The mixture was stirred at room temperature for 24 hours, after which the solvent and excess propylene oxide were removed using a rotary evaporator. (S)-2,2'-((7-2-hydroxypropyl)-1,4,7-triazacyclononane-1,4-diyl)bis(methylene))diphenol was purified using a silica gel column (using a gradient of hexane and ethyl acetate, followed by a gradient of ethyl acetate and methanol). Impurities were removed in the hexane and ethyl acetate gradient, and a clean product was eluted (with 90% ethyl acetate and 10% methanol). MS-ESI + 400.67 (M+H + , 100%), 422.50 (M+Na + , 35%). [ka] (S)-2,2'-((7-2-hydroxypropyl)-1,4,7-triazacyclononane-1,4-diyl)bis(methylene))diphenol (0.1 mmol) was dissolved in 5 mL of ethanol and stirred at 80°C. Iron(III) chloride (0.15 mmol, 1.5 equivalents) was dissolved in 5 mL of ethanol and added dropwise to the ligand solution. The mixture was stirred at 80°C for 24 hours, and then reduced to 3 mL. Diethyl ether was slowly added to the remaining solution while stirring to precipitate the iron complex. The complex was recovered by centrifugation, washed with ether until the supernatant was clear, and the solid was dried in a vacuum line. MS-ESI + 453.83 (M+H + , 100%) [Example 5]

[0124] The following examples illustrate the details of the synthesis of macrocyclic complexes and compounds of the present disclosure.

[0125] Synthesis of 3-formyl-4-hydroxybenzenesulfonate sodium salt [ka] Salicylaldehyde (5.38 mL, 50.0 mmol) and aniline (4.61 mL, 50.0 mmol) were stirred at 50°C for 4 hours. The solution was then placed in a chemical freezer until a yellow solid precipitate formed. The precipitate was filtered, washed with cold ethanol, and then recrystallized in hot ethanol to obtain salicylaniline as yellow needle-shaped crystals in quantitative yield. ESI-MS (m / z): [MH] + =198.20 (100)

[0126] Salicylaniline (3.50 g, 17.8 mmol) was dissolved in 10.0 mL of concentrated sulfuric acid and heated at 105-110°C for approximately 3 hours. After completion, the solution was carefully poured into 100 mL of ice water to form a brown precipitate. The solution was then heated to a boil and filtered by gravity. The filtrate was cooled in an ice bath until a brown solid precipitated. The precipitate was filtered and washed to produce 4-hydroxy-3-[(phenylimino)methyl]benzenesulfonic acid as a brown solid. Yield: 2.53 g (51%). ESI-MS (m / z): [MH] + =278.24 (100)

[0127] 4-hydroxy-3-[(phenylimino)methyl]-benzenesulfonic acid (2.53 g, 9.12 mmol) was dissolved in 17.0 mL and stirred in a 50 mL Erlenmeyer flask. Sodium carbonate (1.02 g, 9.62 mmol) was slowly added over 30 minutes. The solution was then boiled vigorously for 2 hours, during which time any lost water was replenished. The solution was cooled to room temperature. Then, 10.2 mL of glacial acetic acid was added to the solution, followed by the same amount of EtOH (~30.0 mL). The solution was cooled in a chemical freezer for several hours to produce fine beige crystals. These crystals were filtered and washed with cold EtOH to obtain 3-formyl-4-hydroxybenzenesulfonate sodium salt as a yellowish-brown crystalline solid. Yield 1.51 g (73%) ESI-MS (m / z) Negative Mode: [M] -1 =201.17 (100)

[0128] Synthesis of 3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzenesulfonate sodium salt. [ka] TACN (0.500 g, 3.87 mmol) was dissolved in 25.0 mL of MeOH and stirred in a 50 mL round-bottom flask. 3-formyl-4-hydroxybenzenesulfonate sodium salt (0.867 g, 3.87 mmol), dissolved in 10.0 mL of MeOH, was slowly added over 1 hour using a 10.0 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.366 g, 9.68 mmol) was slowly added, and the solution was reacted for 1 hour. The solvent was removed under pressure, and the crude product was passed through a small plug of basic alumina using a 90:10 DCM / MeOH solution as the eluent. The crude product was isolated as a yellow oily substance. The crude 3-((1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzenesulfonate sodium salt was used without further purification. ESI-MS (m / z): [MH] + =316.37 (100), [M-Na] + =338.31 (30)

[0129] Crude 3-((1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzenesulfonate sodium salt (0.328 g, 0.970 mmol) was dissolved in 10 mL of a 50:50 EtOH / water mixture and stirred in a 20 mL scintillation vial. Next, (S)-(-)-propylene oxide (349 μL, 4.84 mmol) was added and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude 3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzenesulfonate sodium salt was obtained by column chromatography using basic alumina, DCM / MeOH (100:0 to 80:20, 0:100 flash). ESI-MS (m / z): [M] - =430.31 (100)

[0130] Synthesis of (S)-3,3'-((7-(2-hydroxypropyl)-1,4,7-triazonan-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt [ka] TACN (0.500 g, 3.87 mmol) was dissolved in 25.0 mL of MeOH and stirred in a 50 mL round-bottom flask. 3-formyl-4-hydroxybenzenesulfonic acid sodium salt (1.73 g, 7.74 mmol), dissolved in 10.0 mL of MeOH, was slowly added over 1 hour using a 10.0 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.732 g, 19.4 mmol) was slowly added, and the solution was reacted for 1 hour. The solvent was removed under pressure, and the crude product was passed through a small plug of basic alumina using a 90:10 DCM / MeOH solution as the eluent. The crude product was isolated as a yellow oily substance. Crude 3,3'-((1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt was used without further purification. ESI-MS (m / z): [MH]- = 500.19 (100)

[0131] Crude 3,3'-((1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt (0.529 g, 0.970 mmol) was dissolved in 10 mL of a 50:50 EtOH / water mixture and stirred in a 20 mL scintillation vial. Next, (S)-(-)-propylene oxide was added (175 μL, 2.43 mmol) and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude (S)-3,3'-((7-(2-hydroxypropyl)-1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt was obtained by column chromatography using basic alumina, DCM / MeOH (100:0 to 80:20, 0:100 flash). ESI-MS (m / z): [MH] - = 558.25 (100)

[0132] Synthesis of 3,3'-((7-methyl-1,4,7-triazonan-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt [ka] TACN (0.500 g, 3.87 mmol) was dissolved in 25.0 mL of MeOH and stirred in a 50 mL round-bottom flask. 3-formyl-4-hydroxybenzenesulfonic acid sodium salt (1.73 g, 7.74 mmol), dissolved in 10.0 mL of MeOH, was slowly added over 1 hour using a 10.0 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.732 g, 19.4 mmol) was slowly added, and the solution was reacted for 1 hour. The solvent was removed under pressure, and the crude product was passed through a small plug of basic alumina using a 90:10 DCM / MeOH solution as the eluent. The crude product was isolated as a yellow oily substance. Crude 3,3'-((1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt was used without further purification. ESI-MS (m / z) negative mode: [MH] - = 500.19 (100)

[0133] Crude 3,3'-((1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt (0.529 g, 0.97 mmol) was dissolved in 10 mL of DMF and heated to approximately 60°C with stirring in a 20 mL scintillation vial. Then, iodomethane (68.0 μL, 1.07 mmol) was added and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude 3,3'-((7-methyl-1,4,7-triazonane-1,4-diyl)bis(methylene))bis(4-hydroxybenzenesulfonic acid) disodium salt was obtained by column chromatography using basic alumina and DCM / MeOH (100:0 to 80:20, 0:100 flash). ESI-MS (m / z): [MH] - = 514.21 (100)

[0134] Synthesis of 3,3',3''-((1,4,7-triazonane-1,4,7-triyl)tris(methylene))tris(4-hydroxybenzenesulfonic acid) trisodium salt (L1), [Fe(L1)Na3] [ka] TACN (0.250 g, 1.94 mmol) was dissolved in 25.0 mL of MeOH and stirred in a 100 mL round-bottom flask. 3-formyl-4-hydroxybenzenesulfonate sodium salt (2.60 g, 11.6 mmol), dissolved in 20.0 mL of MeOH, was slowly added over 1 hour using a 25 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.550 g, 14.6 mmol) was slowly added, and the solution was reacted for 1 hour. The solvent was removed under vacuum, and the crude product was dissolved in 10 mL of MeOH. The solution was heated to a boil and cooled to room temperature. The solution was stored overnight (approximately 12 hours) in a chemical freezer. The formed precipitate was filtered and washed with cold EtOH to obtain 3,3',3''-((1,4,7-triazonane-1,4,7-triyl)tris(methylene))tris(4-hydroxybenzenesulfonic acid) trisodium salt as a white solid. Yield 0.512 g (approximately 35%). ESI-MS (m / z): [MH] 2- =343.00 (100%)

[0135] 3,3',3''-((1,4,7-triazonane-1,4,7-triyl)tris(methylene))tris(4-hydroxybenzenesulfonic acid) trisodium salt (0.206 g, 0.273 mmol) was dissolved in 5 mL of water and stirred in a 20 mL scintillation vial at approximately 60°C. Anhydrous ferrous chloride (0.035 g, 0.273 mmol) dissolved in 5 mL of water was gradually added to the stirred solution. The reaction was monitored by ESI-MS and completed after approximately 2 hours. The solvent was removed under vacuum, and the crude oily substance was dissolved in 2 mL of MeOH. Upon addition of diethyl ether, a dark reddish-brown solid precipitated, which was filtered, washed with cold EtOH, and dried under vacuum. Subsequent precipitation and washing yielded [Fe(L1)Na3] as a reddish-brown solid. Yield 0.140 g (approximately 63%). ESI-MS (m / z): [M] 3- =245.82 (100)

[0136] Synthesis of diethyl(3-formyl-4-hydroxybenzyl)phosphonate [ka] Paraformaldehyde (1.58 g, 50.0 mmol) was dissolved in 12 M HCl (60 mL) and stirred in a 100 mL round-bottom flask. Once all the paraformaldehyde was dissolved, salicylaldehyde (5.38 mL, 50.0 mmol) was slowly added using a 10 mL addition funnel. The solution was stirred for 3 days, and the resulting pink precipitate was filtered and washed with water until the filtrate was clear. The slightly pink solid was dissolved in diethyl ether, dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. The crude product was recrystallized from heated hexane to obtain a white solid. 5-(chloromethyl)-2-hydroxybenzaldehyde was used directly in the next reaction without further purification.

[0137] 5-(chloromethyl)-2-hydroxybenzaldehyde (2.25 g, 13.2 mmol) was added to a 10 mL round-bottom flask equipped with a stirring bar. Triethyl phosphite (2.54 mL, 14.5 mmol) was added very slowly to the round-bottom flask, taking care not to let the reaction mixture overflow. After all of the triethyl phosphite had been added, a condenser was attached to the flask and the reaction was heated to approximately 90°C overnight (approximately 12 hours). The condenser was then replaced with a vacuum distillation apparatus to remove liquid impurities. (3-formyl-4-hydroxybenzyl)phosphonate was purified by column chromatography and silica hexane / siRNA (90:10~0:100) to obtain an off-white oily substance. Yield 3.31 g (approximately 92%). ESI-MS (m / z): [MH] + =273.65 (100)

[0138] Synthesis of (3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonic acid (TPP), [Fe(TPP)Cl] [ka] TACN (1.23 g, 9.25 mmol) was dissolved in 25 mL of MeOH and stirred in a 50 mL round-bottom flask. (3-formyl-4-hydroxybenzyl)phosphonate (2.52 g, 9.25 mmol) in 10 mL of MeOH was slowly added to the round-bottom flask using a 10 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.875 g, 23.1 mmol) was slowly added, and the solution was stirred for 1 hour. The solvent was removed under pressure, and the crude product was purified by column chromatography, basic alumina, and CHCl3 / MeOH (99:1~0:100). Diethyl (3-((1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonate was isolated as a yellow oily substance. Yield 2.14 g (approximately 60%). ESI-MS (m / z): [MH] + =386.64 (100)

[0139] Diethyl (3-((1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonate (1.07 g, 2.78 mmol) was dissolved in 18 mL of a 50:50 EtOH / water mixture and stirred in a 20 mL scintillation vial. Next, (S)-(-)-propylene oxide (1.00 mL, 13.9 mmol) was added and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude diethyl (3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonate was obtained by column chromatography using basic alumina, DCM / MeOH (100:0~80:20, 0:100 flash). ESI-MS (m / z): [MH] + =502.77 (100), [(M-2H) / 2] + =252.47 (35)

[0140] Diethyl (3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonate (0.255 g, 0.508 mmol) was dissolved in 10 mL of DCE in a 25 mL round-bottom flask. With stirring, TMS-Br (678 μL, 5.08 mmol) was slowly added over approximately 10 minutes. A condenser was attached and the solution was refluxed overnight (approximately 12 hours). The reaction was then quenched with 10 mL of water. The water was collected and the DCE was washed with water (3 × 25 mL). The aqueous layers were combined and the solvent was removed under vacuum. The crude product was washed with cold EtOH to obtain (3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonic acid as a white solid. Yield: 0.075g (approximately 33%) ESI-MS (m / z): [MH] + =446.61 (100)

[0141] (3-((4,7-bis((S)-2-hydroxypropyl)-1,4,7-triazonan-1-yl)methyl)-4-hydroxybenzyl)phosphonic acid (L2) (0.031 g, 0.070 mmol) was dissolved in 2 mL of EtOH and heated to 60°C with stirring in a 1 DRAM vial. Next, anhydrous ferrous chloride (0.009 g, 0.070 mmol) was dissolved in 1 mL of EtOH and slowly added to the solution. The solution was stirred overnight (approximately 12 hours). The solvent was removed under vacuum, and the crude oily substance was dissolved in 1 mL of MeOH. The iron complex [Fe(L2)Cl] was precipitated from the solution using diethyl ether to obtain a dark purple solid. Yield: 0.024 g (approximately 65%). ESI-MS (m / z): [M] + =499.24 (100)

[0142] Synthesis of (2S,2'S)-1,1'-(7-((3-hydroxypyridine-4-yl)methyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L3), [Fe(L3)Cl] [ka] TACN (0.500 g, 3.87 mmol) was dissolved in 25 mL of MeOH and stirred in a 50 mL round-bottom flask. 3-hydroxy-4-pyridinecarboxaldehyde (0.491 g, 3.87 mmol) in 10 mL of MeOH was slowly added to the round-bottom flask using a 10 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.366 g, 9.68 mmol) was slowly added, and the solution was stirred for 1 hour. The solvent was removed under pressure, and the crude product was purified by column chromatography using basic alumina, DCM / MeOH (100:0~80:20, 0:100 flash). Crude 4-((1,4,7-triazonan-1-yl)methyl)pyridine-3-ol was isolated as an orange-yellow oily substance. The crude purified product was used in subsequent reactions without further purification. ESI-MS (m / z): [MH] + =237.50 (100)

[0143] Crude 4-((1,4,7-triazonan-1-yl)methyl)pyridine-3-ol (0.295 g, 1.25 mmol) was dissolved in 10 mL of 80:20 EtOH / water mixture and stirred in a 20 mL scintillation vial. Next, (S)-(-)-propylene oxide (451 μL, 6.25 mmol) was added and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude (2S,2'S)-1,1'-(7-((3-hydroxypyridine-4-yl)methyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L3) was obtained by column chromatography using basic alumina, DCM / MeOH (100:0~80:20, 0:100 flash). The crude product was isolated as a yellow oily substance. ESI-MS (m / z): [MH] + =353.34 (100)

[0144] (2S,2'S)-1,1'-(7-((3-hydroxypyridine-4-yl)methyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L3) (0.038 g, 0.108 mmol) was dissolved in 2 mL of EtOH and heated to 60°C with stirring in a 1 DRAM vial. Next, anhydrous ferrous chloride (0.014 g, 0.108 mmol) was dissolved in 1 mL of EtOH and slowly added to the solution. The solution was stirred overnight (approximately 12 hours). The solvent was removed under vacuum and the crude oily substance was dissolved in 1 mL of MeOH. The iron complex [Fe(L3)Cl] was precipitated from the solution using diethyl ether to obtain an orange solid. ESI-MS (m / z): [M] + = 406.76 (100). Longitudinal relaxation capacity (33℃, 1.4 T, 100 mM NaCl, 10 mM HEPES, pH 7) is 1.3 ± 0.1 mM -1 s -1 .

[0145] Synthesis of (2S,2'S)-1,1'-(7-(2-hydroxy-5-methoxybenzyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L4),[Fe(L4)Cl] [ka] TACN (0.500 g, 3.87 mmol) was dissolved in 25 mL of MeOH and stirred in a 50 mL round-bottom flask. 2-hydroxy-5-methoxybenzaldehyde (493 μL, 3.87 mmol) in 10 mL of MeOH was slowly added to the round-bottom flask using a 10 mL addition funnel. The solution was stirred overnight (approximately 12 hours). Then, sodium borohydride (0.366 g, 9.68 mmol) was slowly added, and the solution was stirred for 1 hour. The solvent was removed under pressure, and the crude product was purified by column chromatography using basic alumina, DCM / MeOH (100:0~80:20, 0:100 flash). Crude 2-((1,4,7-triazonan-1-yl)methyl)-4-methoxyphenol was isolated as a yellow oily substance. The crude purified product was used in subsequent reactions without further purification. ESI-MS (m / z): [MH] + =266.66 (100)

[0146] Crude 2-((1,4,7-triazonan-1-yl)methyl)-4-methoxyphenol (0.371 g, 1.40 mmol) was dissolved in 10 mL of 80:20 EtOH / water mixture and stirred in a 20 mL scintillation vial. Next, (S)-(-)-propylene oxide (488 μL, 6.98 mmol) was added and the mixture was reacted overnight (approximately 12 hours). The solvent was removed under vacuum, and crude (2S,2'S)-1,1'-(7-(2-hydroxy-5-methoxybenzyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L4) was obtained by column chromatography using basic alumina, DCM / MeOH (100:0~80:20, 0:100 flash). The crude product was isolated as a yellow oily substance. ESI-MS (m / z): [MH] + =382.93 (100)

[0147] (2S,2'S)-1,1'-(7-(2-hydroxy-5-methoxybenzyl)-1,4,7-triazonan-1,4-diyl)bis(propan-2-ol)(L4) (0.028 g, 0.074 mmol) was dissolved in 2 mL of EtOH and heated to 60°C with stirring in a 1 DRAM vial. Then, iron(II) chloride tetrahydrate (0.015 g, 0.074 mmol) was dissolved in 1 mL of EtOH and slowly added to the solution. The solution was stirred overnight (approximately 12 hours). The solvent was removed under vacuum and the crude oily substance was dissolved in 1 mL of MeOH. The iron complex [Fe(L4)Cl] was precipitated from the solution using diethyl ether to obtain an orange solid. ESI-MS (m / z): [M] + =436.36 (100)

[0148] Synthesis of (2R,2'R,2''R)-3,3',3''-(1,4,7-triazonane-1,4,7-triyl)tris(2-hydroxypropanoate)trilithium salt (L5) [ka] TACN (0.100 g, 0.773 mmol) was dissolved in 10 mL of t-butanol and stirred in a 20 mL scintillation vial. (R)-methylglycidate (332 μL, 7.73 mmol) was added, and the solution was stirred overnight (approximately 12 hours). The solvent was removed under pressure to obtain crude trimethyl 3,3',3''-(1,4,7-triazonane-1,4,7-triyl)(2R,2'R,2''R)-tris(2-hydroxypropanoate) as a red oily substance. The crude product was used in subsequent reactions without further purification. ESI-MS (m / z): [MH] + =436.82 (100)

[0149] 3,3',3''-(1,4,7-triazonane-1,4,7-triyl)(2R,2'R,2''R)-tris(2-hydroxypropanoate) (crude oily substance from the previous step) was stirred overnight (approximately 12 hours) in a 4 mL solution of MeOH:2M LiOH. The solvent was removed under pressure to obtain crude (2R,2'R,2''R)-3,3',3''-(1,4,7-triazonane-1,4,7-triyl)tris(2-hydroxypropanoate) (L5) as a reddish-brown solid. The crude product was used in subsequent reactions without further purification. ESI-MS (m / z): [M-2H] - =392.33

[0150] (2R,2'R,2''R)-3,3',3''-(1,4,7-triazonane-1,4,7-triyl)tris(2-hydroxypropanoate)(L5) (0.195 g, 0.473 mmol) was dissolved in 5 mL of water and stirred in a 20 mL scintillation vial. The solution was heated to approximately 60°C. Anhydrous ferrous chloride (0.060 g, 0.473 mmol) was dissolved in 5 mL of water and slowly added to the solution. The solution was stirred overnight (approximately 12 hours). The solvent was removed under pressure to obtain crude [Fe(L5)Cl] as a reddish-brown solid. ESI-MS (m / z): [M-Cl] - =481.18 (100) [Example 6]

[0151] This embodiment describes the synthesis of the macrocyclic body of the present disclosure.

[0152] Synthesis of 1-benzyl(2-sulfonate),4,7-bis(2-hydroxypropyl)1,4,7-triazacyclononane [ka] Add 198 mg of 1,4,7-triazacyclononane (TACN, 1.55 mmol) to 10 mL of ethanol and stir. At the same time, dissolve 2-sulfabenzaldehyde sodium salt in 14 mL of methanol and add it dropwise to the reaction mixture. Reflux the reaction mixture for 2 hours until it turns pale yellow. Stop heating the reaction mixture and cool it while stirring. Place the crude raw material into a column and analyze it in negative mode [MH]. + +Na + A fraction showing m / z of 321 was pooled and reacted with 3.6 equivalents of s-(-)-propylene oxide in water. After one week, the data showed that the bis(2-hydroxypropyl) ligand (m / z=246 [M+H + Since it showed an abundance of [ ], the crude product was dried and redissolved in 1,2-dichloroethane containing 1 equivalent of 2-sulfabenzaldehyde sodium salt (0.197 g) and 1 equivalent of glacial acetic acid (54 μL). After stirring for 1 hour, 1.2 equivalents of triacetoxyborohydride sodium (240 mg) were added, and product formation began within 1 hour. After 2 days, the reaction was quenched with 20 mL of 1 M NaOH to separate dichloroethane from the aqueous component. The aqueous component was washed with dichloromethane (30 mL), and the organic matter was dried. The organic oily substance was then subjected to silica column chromatography using an aqueous solution of ethyl acetate:methanol:10% ammonium hydroxide. A yellow oily substance was isolated by column chromatography. Mass spectrometry (ESI): m / z=416 [M+H + ], 438 [M+Na + ]

[0153] Iron coordination to 1-benzyl(2-sulfonate) and 4,7-bis(2-hydroxypropyl)1,4,7-triazacyclononane [ka] The crude ligand (assuming 44.6 mg, 0.102 mmol sulfonic acid) was stirred in 2 mL of ethanol. Next, 31.7 mg of iron(II) chloride tetrahydrate (0.159 mmol) was dissolved in 1 mL of ethanol. This iron solution was added to the stirred ligand solution and stirred under heating. The solid was precipitated with diethyl ether and then dried in a SpeedVac to isolate it. MS, ESI: 469.8 [Fe(L-2H + ) + ]

[0154] Preparation of 1-formyl,4,7-bis(2-hydroxypropyl)1,4,7-triazaciconane [ka] The synthesis of 1-formyl-1,4,7-triazacyclononane has already been reported (Creaser, P. et al. Aust. J. Chem. 2003, 56, 61-64). 0.9925 g of this substance is mixed with 993 μL of 98% s-(-)-propylene oxide in 10 mL of methanol (overnight). The next day, the crude product is dried and analyzed on a silica column using siRNA:MeOH (0-60%MeOH). The isolated product is dried to yield 1.433 g of an oily substance with M / Z = 274 [M+H + It has ].

[0155] Preparation of 1,4-bis(2-hydroxypropyl)-1,4,7-triazacyclononane [ka] Dissolve the product from the previous step in 30 mL of 92% ethanol and 5 mL of water (containing 2.5 g of NaOH), and stir at 75-80°C. After 4 days, stop heating the reaction mixture, let it cool, add 20 mL of water, and wash with chloroform (100 mL, 3 times). Dry the organic wash with sodium sulfate, filter, and then dry until it becomes an oily substance (1.156 g). Mass spectrometry, +ve mode, m / z=246 [M+H + ]

[0156] Preparation of 1-(benzyl-2-sulfonate)-4,7-bis(hydroxypropyl)-1,4,7-triazacyclononane [ka] The crude product was dissolved in 12 mL of methanol to recover approximately 50 mg of oily substance (0.204 mmol), and 500 μL was drawn up and diluted to 5 mL with methanol. 88 mg of 2-sulfabenzaldehyde sodium salt (0.423 mmol) was added to this solution and the mixture was reacted on a hot plate for 2 hours under near reflux. After 2 hours, the reaction mixture was cooled, and 31 mg of sodium borohydride (0.819 mmol) was added and the mixture was stirred for 1 hour. The reaction was then quenched with 3 M HCl until the bubbles stopped, and the solution was basicized with 10 M NaOH. The solution was further diluted with 5 mL of water. The product was extracted with dichloromethane and dried. The organic oily substance was purified with silica (using an 8:2:1 → 3:2:1 Â:MeOH:10% ammonium hydroxide aqueous solution) to obtain a yellow oily substance. Mass spec M / Z (+ve mode)=416.3 [M - +2H + ], 438.3 [M - +H + +Na + ] [Example 7]

[0157] This embodiment describes the synthesis of the macrocyclic body of the present disclosure.

[0158] Addition of phenacyl bromide and reduction to alcohol [ka] i) N,N-dimethylformamide, dimethylformamide, toluene ii) a) Phenacyl bromide, THF b) 1:1 HBr:MeOH, reflux, then add HBr to the precipitate iii) MeOH, 0℃, NaBH4 Crude protected TACN ligand (7.05 mmol) was dissolved in 15 mL of tetrahydrofuran, filtered to remove insoluble matter, and then stirred in a round-bottom flask. Next, phenacyl bromide (1.447 g, 7.27 mmol) was dissolved in 20 mL of THF and added over 45 minutes via an addition funnel. During this time, solid formation began, and the reaction product turned milky white. The mixture was stirred overnight, and the next day the solid was filtered to obtain a beige solid, which was washed with 60 mL of diethyl ether. Next, this substance was dissolved in 100 mL of 1:1 MeOH:HBr solution and refluxed for 6 hours. After that, the reaction product was cooled to room temperature, and then another 50 mL of HBr was added. The reaction product was left to stand in a freezer overnight. The resulting solid was filtered and collected, washed with diethyl ether, and 6.64 g of HBr salt was obtained.

[0159] Dissolve 2.36 g of this solid in 25 mL of water, neutralize with 0.35 g of NaOH, and then add the pellet to raise the pH of the solution to 10 or higher. Wash the resulting solution with chloroform (3 × 30 mL). Combine the organic layer, dry with sodium sulfate, filter, and then dry with a rotary evaporator. Mass of oily substance: 0.5661. Mass spectrometry: m / z = 248 [M + H + ] Next, this oily substance is stirred in 25 mL of methanol in a round-bottom flask placed in an ice bath (<10°C). 1.88 g of sodium borohydride (NaBH4, 49.7 mmol) is slowly added to the cold solution while stirring. After stirring the reaction mixture in the ice bath for 10 minutes, the ice bath is removed and the mixture is stirred at room temperature for 3 hours. When the reaction is complete, as determined from the mass spectrometer data (M / Z = 250[M+H]), the reaction is measured. +The solution was neutralized with hydrochloric acid (HCl) to quench any remaining boron hydride. Then, sodium hydroxide pellets (8 pellets) were added to raise the pH of the solution to above 10, and the product was recovered by water-organic extraction (chloroform, 3 x 50 mL). The organic layer was pooled, dried over sodium sulfate, filtered, and then passed through a rotary evaporator to obtain an oily substance (up to 0.3431 g in a round-bottom flask). This oily substance was used in the next step without further purification.

[0160] Addition of a hydroxypropyl group [ka] Dissolve the crude product (0.3431 g) isolated in the previous step in 15 mL of methanol, and add 2.4 equivalents of 98% s-(-)-propylene oxide (236 μL) by pipette. The following day, add another 300 μL of s-(-)-propylene oxide to complete the reaction. Dry the reaction product on the third day. Purify the ligand by column chromatography of basic alumina (0-5% MeOH in dichloromethane). Mass spectrometry: M / Z = 366. [M+H + ]

[0161] Metallation of ligands (L) by iron. [ka] The ligand (0.0433 g, 0.1186 mmol) was dissolved in a minimal amount of ethanol. One equivalent of anhydrous ferrous chloride (0.015 g) was dissolved in ethanol and added to the ligand. The solution was heated with stirring, and the product was precipitated and isolated with diethyl ether. MS: 419 [Fe(L-2H + ) + ] When the complex was measured by 1.4T benchtop NMR at 33°C and pH 7.2, r1 = 1.6m M -1 s -1 This was obtained.

[0162] Synthesis of bis(glycidate)phenyl alcohol TACN [ka] 0.578 g of phenyl alcohol TACN in 15 mL of tert-butanol is mixed with 1.26 mL of R-methylglycidate. The reaction mixture is stirred overnight. The next day, mass spectrometry revealed the main peak of the product (M / Z, ESI=454[M+H]). + ]). The main peak remained for the substance insoluble in ethyl acetate (after 6 consecutive washes with ethyl acetate). 670 mg of the substance was isolated. This was used in the next step.

[0163] Glycidate deprotection [ka] The product from the previous step was dissolved in 18 mL of methanol and added to 18 mL of 2 M LiOH solution. The reaction was set to 50°C and stirred overnight. The next day, the conversion to the product was confirmed by mass spectrometry. (M / Z, ESI + Mode: 426.3 [M+H + ], Negative mode: 424.2 [MH + ].) [Example 8]

[0164] This embodiment describes the synthesis of macrocyclic compounds of the present disclosure.

[0165] [ka] TACN (0.2449 g, 1.90 mmol) was added to a 50 mL round-bottom flask and dissolved in ethanol. Next, 0.6765 g (6.24 mmol) of 1,1,1-trifluoro-2,3-epoxypropane was added to the flask and stirred overnight at room temperature. The solvent was removed by rotary evaporation to obtain a pale yellow oily substance. ESI-MS m / z: 466.32 (100%) [M+H + ] + . 1H NMR (400MHz, CDCl3, 25℃): δ 1.22 (t), 2.46-2.99 (m), 3.69 (q), 4.04 (s).

[0166] [ka] An ethanol solution of the "TAFO" ligand (0.1335 g, 0.287 mmol) was mixed with an equimolar ethanol solution of FeCl2·4H2O (0.0582 g), and the mixture was stirred overnight at room temperature. After 24 hours, 0.0241 g of FeCl2·4H2O was added to the reaction mixture. After completion, ethyl ether was added to the reaction mixture to precipitate the complex as a yellow solid, which was then washed twice with ethyl ether. ESI-MS m / z: 519.36 (100%) [M+H + ] +

[0167] [ka] 0.0486 g (0.483 mmol) of the "NitroBzTACN" ligand was added to a scintillation vial and dissolved in ethanol. Next, 0.1624 g (1.45 mmol) of 1,1,1-trifluoro-2,3-epoxypropane was added and the mixture was stirred overnight at room temperature. After 24 hours, 0.1624 g of 1,1,1-trifluoro-2,3-epoxypropane was added and the reaction mixture was stirred overnight at room temperature. The solvent was removed by rotary evaporation to obtain a pale yellow oily substance. ESI-MS m / z: 489.40 (100%) [M+H + ] +

[0168] [ka] 70.1 mg (0.144 mmol) of the "NitroBzTAFO" ligand was added to a scintillation vial and dissolved in ethanol. An ethanol solution of FeCl2·4H2O (0.0316 g, 5% molar excess) was added and the mixture was stirred overnight at room temperature. After 24 hours, 0.0377 g of FeCl2·4H2O was added to the reaction mixture and the mixture was stirred overnight. After the reaction was complete, ethyl ether was added to the reaction mixture to precipitate the complex as a yellow solid, and the mixture was washed twice with ethyl ether. ESI-MS m / z: 542.40 (100%) [M-Cl - ] + [Example 9]

[0169] This embodiment describes the synthesis of the macrocyclic body of the present disclosure. [ka]

[0170] General procedure

[0171] The ligand is prepared as mono- or disubstituted 1,4,7-triazacyclononane before adding the polyhydroxylated substance. Next, the crude ligand is heated and stirred in alcohol with 1.2 to 3.6 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane. The reaction is completed within 2 to 24 hours. The ligand is purified by column chromatography or the solid is isolated by filtration. Next, the protected ligand is deprotected by refluxing in water with a diluted concentrated aqueous acid (hydrobromic acid or hydrochloric acid) or by mixing in alcohol (methanol or ethanol) at room temperature. The liberated polyhydroxylated ligand is purified by neutralization and extraction or by column chromatography. Finally, the ligands are stirred in ethanol, and the iron complex is prepared by either 1) adding an ethanol solution of anhydrous ferrous salt (which forms a ferric complex upon oxidation; for ligands without a coordinating group) or 2) adding an ethanol solution of ferric salt (FeCl3) (for ligands with a coordinating group, such as L6A). The substance is stirred until complete conversion to the metal complex is observed by mass spectrometry.

[0172] Determination of longitudinal relaxation time (T1) and relaxation rate (R1)

[0173] Serial dilutions of the iron complex were prepared from a stock solution containing 5–10 mM of the complex (with or without 2 equivalents of meglumine) in 100 mM NaCl and 10–20 mM HEPES buffer (pH 7.2). These three concentrations and a blank were tested using a Nanalysis 60Pro NMR (set to operate at a magnet temperature of 33°C (locked with deuterated solvent)). After calibrating the instrument to the solvent, the proton spectra of the samples were collected and processed to focus on the water signal. Next, the experiment was performed multiple times with a single sample, focusing on i) the appearance of the water signal in the final scan, ii) the number of data points on the plateau of the peak integral curve over time, and iii) whether the relaxation time did not change with increasing the delay time (in seconds as measured by the instrument). The obtained concentrations were then expressed as concentration (x-axis) versus the reciprocal of relaxation time (1 / T1, s). -1The results are plotted on a graph. The slope of the regression line is then interpolated as the relaxation rate R1 of the complex under these conditions.

[0174] synthesis

[0175] Both benzyl TACN and benzoate TACN have been synthesized previously. [ka]

[0176] Synthesis of the above L1A ligand

[0177] Step 1. Manufacturing procedure for bis(tri(hydroxy)butyl)-protected benzyl TACN (official name: (5S,6R)-6-(4-benzyl-7-((5R,6R)-6-hydroxy-2,2-dimethyl-1,3-dioxepan-5-yl)-1,4,7-triazonan-1-yl)-2,2-dimethyl-1,3-dioxepan-5-ol)

[0178] Benzyl TACN is dissolved in water and basicized to pH 10. The ligand is then extracted with chloroform, the organic solution is dried over sodium sulfate, filtered, and evaporated to obtain an oily substance. The oily substance is weighed to determine the number of moles of the starting material. 675 mg of the substance is heated (70°C) and stirred in 6 mL of anhydrous ethanol. To the stirred solution, 2.2-3.6 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane are added using a pipette (1.44 mL). The reaction mixture is heated and stirred overnight in a flask fitted with a water condenser. The next day, the target peak (508 m / z ratio, M+H) is obtained by mass spectrometry. +Since the product obtained was , the reaction was stopped and the solution was dried to obtain an oily substance. Next, this oily substance was dissolved in an organic solvent and loaded onto a silica column (approximately 15-20x relative to the mass of the crude material), and passed through the column. First, to remove excess unreacted epoxide, 4-4.5 column volumes (CV) of hexane:ethyl acetate (4:1) were passed through, followed by 1 CV of hexane:ethyl acetate (1:4). Next, 3 CV of ethyl acetate:methanol:10% ammonium hydroxide aqueous solution (8:2:1) were passed through the column to elute the product. This product has a retention factor of 0.35-0.5 in the 8:2:1 solution.

[0179] Step 2. Deprotecting the epoxide generates a hydroxyl group.

[0180] The ligand is stirred in a 3% acid (HBr or HCl) solution in alcohol (methanol or ethanol) and shaken for approximately 3-5 minutes. This solution is analyzed by mass spectrometer to confirm the deprotection of the group (m / z: 428 M+H + The ligand solution is allowed to stand overnight to form a solid. If no solid precipitates, the solution is worked up to purify the product. The acidic solution is neutralized with sodium hydroxide solution, and this solution is concentrated using a rotary evaporator. The resulting solid is extracted with anhydrous ethanol, the ethanol solution is transferred to a flask, and dried to obtain an oily substance.

[0181] Examples of deprotection and purification by neutralization

[0182] 800 mg of the protected ligand was stirred in an acidic alcohol solution (4% HCl in EtOH). Mass spectrometry analysis revealed the target product (m / z 428, M+H). + After the result was shown, the solution was basicized with potassium hydroxide and the solvent was removed under vacuum. Then, the coarse salt was washed with anhydrous ethanol and placed in a centrifuge tube. The sample was spun down to separate and recover the solution from the unwanted sodium chloride. This liquid was placed in a weighed vial, dried, and placed under vacuum. The final mass of the substance in the vial (used for metallization) was 418 mg. [ka]

[0183] L2A synthesis

[0184] Step 1. Reductive amination of methyl(2-sulfonate)TACN

[0185] 152.8 mg of 1,4,7-triazacyclononane is stirred in a two-necked round-bottom flask containing 40 mL of 1,2-dichloroethane. Next, 1 equivalent of sodium 2-sulfabenzaldehyde (208.16 g / mol FW, 246.2 mg white powder) is added to the flask, and 1 equivalent of glacial acetic acid (0.068 mL, 68 μL) is added by pipette. The reaction is stirred overnight. The next day, approximately 3.0 equivalents of sodium tri(acetoxy)borohydride (211.94 g / mol, white powder, 760 mg) is added to the flask to first produce a clear solution (until turbidity returns after 20 minutes). After stirring the reaction mixture for a further 2 days, the reaction mixture is filtered, the solid is collected and analyzed by mass spectrometry (ESI-MS = 300 m / z, [M]). - +2H + ], M - This represents the sulfonic acid anion derivative of the product. The crude product is washed with 10 mL of 92% ethanol to remove the acetate, and the solid is used in the next synthesis step without further purification.

[0186] Step 2. 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane is added to obtain 2-((4-((5R,6R)-6-hydroxy-2,2-dimethyl-1,3-dioxepand-5-yl)-7-((5R,6S)-6-hydroxy-2,2-dimethyl-1,3-dioxepand-5-yl)-1,4,7-triazonan-1-yl)methyl)benzenesulfonate.

[0187] 204.7 mg of TACN sulfonic acid material (FW = 299 g / mol, 0.685 mmol) obtained from the previous step was stirred in a 1:1 methanol:water (MeOH:H2O, 10 mL). One pellet of NaOH was added to basicize the solution. Next, 2.2 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane were added (197 μL). The reaction mixture was stirred overnight and heated between 58 and 64°C. The next day, the reaction mixture was cooled to room temperature and the product was analyzed by mass spectrometry. The main product was m / z 610[M+Na + ], then, m / z 588[M+H + ] (M is a neutral ligand). The reaction mixture was washed with ethyl acetate (30 mL Â, then 20 mL), the organic layer was dried together over sodium sulfate, and filtered. Next, this material was run on a column (8 g silica, CV approximately 22 mL), and the crude product was eluted first with 100% Â (approximately 2.5 column volumes), then with an Â:MeOH:10% ammonium hydroxide aqueous solution in an 8:2:1 ratio (approximately 3.1 column volumes), and finally with a 2 column volume Â:MeOH:10% ammonium acetate aqueous solution (3:2:1). (Rf product in 8:2:1 acetone:MeOH:10% ammonium hydroxide aqueous solution, 0.3-0.4)

[0188] Step 3. Deprotection is performed to produce a 1,2,4-trihydroxylbutane pendant, and the ligand: 2-((4,7-bis((2R,3S)-1,3,4-trihydroxybutan-2-yl)-1,4,7-triazonan-1-yl)methyl)benzenesulfonate.

[0189] The purified substance (estimated at 160.8 mg of ammonium L3A precursor, 0.266 mmol) is dissolved in a 1:2 mixture of hydrobromic acid (HBr) and acetic acid (AcOH) (500 μL of HBr, 1 mL of AcOH), shaken for 3 minutes, and then placed in a freezer. If no precipitate forms, 1-2 mL of 92% ethanol is added, and the reaction mixture is allowed to stand in a hood. The reaction mixture is dried to form an oily substance, and the crude substance is purified by redissolving it in water. The reaction mixture is then dissolved in 3.5 g of Dowex 50WX4 cation exchange resin (H + Chromatography is performed using a chromatograph. The substance is loaded onto a resin, 30 mL of water is passed through it, and the product is eluted with a 5% aqueous ammonium hydroxide solution. After adding ammonium to the column, the product is eluted. The crude product is dried in a weighed vial and left under vacuum overnight. The final mass of the product is 110.3 mg (0.210 mmol, yield 79% for the ammonium salt of the product). m / z: 508 [M+H + ], 530 [M+Na + Here, M is a neutral ligand. [ka]

[0190] L3A ligand synthesis

[0191] Step 1. Addition of protected tri(hydroxy)butyl group. The protected 4-((1,4,7-triazacyclononan-1-yl)methyl)benzoic acid hydrobromide ethyl salt product (3.195 g) is deprotected by stirring in 45 mL of 1 M NaOH, and the reactant is solubilized by adding a small amount of methanol. The reactant is stirred at 60-70°C for 2 days. The reactant is then dried and redissolved in a small amount of ethanol (7 mL). Next, 3.6 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane are added (3.98 mL), and the mixture is stirred under heating. The reactant solidifies within a few hours, yielding an off-white solid. The reaction mixture is filtered to separate the solid from the liquid. The mass spectrum of the solid matches the product (m / z ratio 552 = M + H +This was then used in the next reaction step.

[0192] Step 2. Formation of tri(hydroxy)butyl pendant by deprotection

[0193] The above solid substance is dissolved in 30 mL of 5.6 M HCl solution (14 mL HCl / 16 mL water), stirred overnight under a condenser, and the temperature is set to 70°C. The next morning, the solution is analyzed by mass spectrometry, and the main product is shown (ESI-MS m / z 472 [M+H + ]). Neutralize and purify the crude ligand. Load the crude solid onto a silica column and elute using a methanol gradient of ethyl acetate with 1% formic acid added as the eluent. The product elutes between 50-100% methanol. To remove unwanted formic acid byproducts, pass the ligand through a Dowex 50WX4 ion exchange resin. Wash the loaded column with water first, then elute the ligand with a 5% NH4OH aqueous solution. Redissolve the substance in water:ethanol and let it stand overnight. The next day, dry the compound under vacuum to produce an oily substance. [ka]

[0194] L6A ligand synthesis

[0195] Step 1. Addition of protective alcohol to the product: (5S,6R)-6-(4-((5R,6R)-6-hydroxy-2,2-dimethyl-1,3-dioxepane-5-yl)-7-(2-hydroxybenzyl)-1,4,7-triazonan-1-yl)-2,2-dimethyl-1,3-dioxepane-5-ol Crude reductive amination of 500 mg of 1,4,7-triazacyclononane in methanol using salicylaldehyde is performed by stirring for 2 hours under heating (55°C thermometer) with 2.2 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane (1.11 mL), after which 1 pellet of sodium hydroxide is added. The reaction mixture is stirred over the weekend, and mass spectrometry reveals 525(M+H) as the major product.+ It is confirmed that the following is observed. The solid precipitate is filtered and discarded, and the methanol solution is dried by half. The solution is diluted with 10 mL of water and washed with dichloromethane (15, 20, 15 mL). The organic layer is pooled, washed with sodium sulfate, and dried until it becomes an oily substance. When this substance is purified by column chromatography (100% ethyl acetate - 3:2:1 Â:MeOH:10% ammonium hydroxide aqueous solution), the desired product is found to be Â:MeOH:NH4OH (10%) between 6:3:1 and 3:2:1. aq ) can be obtained from this.

[0196] Step 2. Alcohol deprotection The column fractions of the product were washed together (10 mL H2O:10 mL dichloromethane), the organic layer was dried over sodium sulfate, filtered, and then evaporated in a round-bottom flask. The orange oily substance obtained from the organic matter was shaken for 5 minutes with 1 mL of concentrated hydrochloric acid diluted to 10 mL with methanol. After 5 minutes, 10 mL of water was added, and the reaction mixture was washed with 75 mL of chloroform (25 mL x 3). The organic layer was discarded, and the aqueous layer was neutralized with 10 M NaOH. This substance was washed again with 75 mL of CHCl3, and the organic layer was discarded again. The aqueous solution was dried, and the salt residue was washed with 30 mL of anhydrous ethanol. The solution was filtered and dried to obtain approximately 400 mg of solid. ESI-MS m / z: 444.7 (M+H + ) [ka]

[0197] L1B ligand synthesis

[0198] Steps 1 and 2. Preparation of TACN (1-benzyl-4-formyl-1,4,7-triazaciclonane)

[0199] In a round-bottom flask, 0.999 g of 1,4,7-triazacyclononane and 1.1 equivalents of N,N-dimethylformamide dimethylacetal (1.165 mL) are stirred in toluene (15 mL). The reaction mixture is stirred at room temperature for 24 hours. The solution is then decanted into another round-bottom flask and dried using a rotary evaporator. A crude oily substance (1.0142 g of material, 94% yield) is obtained and stirred in 15 mL of tetrahydrofuran (THF, sieved and dried). 1 equivalent of benzyl bromide (877 μL) is added dropwise to another 20 mL of THF over 25 minutes. The reaction mixture is sealed and stirred to rapidly form a white product. The next day, the solid is collected by vacuum filtration and washed with a small amount of diethyl ether. The solid is placed in a clean round-bottom flask, dissolved in approximately 12 mL of distilled water, and stirred at 76°C for 48-72 hours. Subsequently, the crude raw material is dried to produce an oily substance. Mass spectrometry (ESI-MS) m / z:248 (M+H + ) And we assumed a conversion rate of 100% from benzyl addition.

[0200] Step 3. Alcohol 1 is added to obtain (S)-4-benzyl-7-(2-hydroxypropyl)-1,4,7-triazonane-1-carbaldehyde. The substance obtained from the previous step is dissolved in 20 mL of 92% ethanol, and 1.2 equivalents of S-(-)-propylene oxide (624 μL) are added to the stirred reaction mixture along with 5 mL of 1 M NaOH solution to induce product formation. The reaction mixture is stirred overnight, and the next day it is analyzed by mass spectrometry (m / z=306, M+H + This substance is used without further purification.

[0201] Step 4. Aldehyde removal The substance obtained from step 3 is stirred under heat for 6 hours with 20 mL of 48% HBr added to the reactants to remove the aldehyde and decompose the remaining propylene oxide. Then, another 20 mL of acid is added to the reaction flask and left to stand overnight in a freezer. The next day, the solution is made basic with 20 g of NaOH, and the crude product is washed twice with 50 mL of dichloromethane. The organic layer is collected, dried over sodium sulfate, and dried in a rotary evaporator to produce an oily substance (m / z 278, M+H + (and impurities at 336 m / z). The crude reaction product is used in the next step (1.723 g).

[0202] Step 5. Addition of protective tri(hydroxy)butyl To this crude substance, 0.85 equivalents of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane were added (0.85 equivalents from the initial 7.296 mmol in the previous step, 810 μL), and this was added to the ligand while stirring in heated methanol (65°C). The following day, analysis by mass spectrometry confirmed the conversion to the product. Next, the ligand was purified using two columns. The ligand was dissolved in 92% ethanol, then in 100% siRNA at column volume (CV), then in 1 CV of siRNA:MeOH:10%NH4OH aqueous solution (9:1:1), 2 CV of 8:2:1, and finally in 1 CV of siRNA:MeOH:NH4OH (aq) The solution was passed through a column using a (3:2:1) ratio. The fractions showing the product by mass spectrometry were combined, dried, and run on basic alumina using a gradient of 0-15% MeOH in DCM. The product was the major product of the two recovered fractions, which was recovered with minimal impurities and dried to an oily substance (to be used in the next step), yielding 320.9 mg of oily substance. m / z 422 [M+H + ], a yield of 9.8% calculated from the departure TACN.

[0203] Step 6. Deprotection of tri(hydroxy)butyl pendant The protective ligand obtained in Step 5 is shaken in 3% HCl in EtOH (4 mL of HCl in 129 mL of 92% EtOH) and set aside. The next day, the solution is neutralized by adding 5.1 M aqueous sodium hydroxide solution dropwise and monitored with a pH meter. When the pH meter shows approximately 7.7, the substance is dried, redissolved in 50 mL of H2O, and washed with 80 mL of dichloromethane to remove unwanted by-products. The aqueous substance is retained and dried under vacuum. This substance is redissolved in chloroform:methanol and flowed through a silica column with 0-100% methanol (in CHCl3). The product is eluted from 20% to approximately 50% methanol. The fraction of interest is collected and the solvent is removed. The obtained solid is washed with 92% ethanol and collected in a weighed vial to obtain 130.4 mg of the product. The product is vacuum dried and analyzed. (m / z ratio: 382=M+H) + )

[0204] General procedure for complexation: Stir the ligand in 2 mL of anhydrous ethanol and heat gently. Next, add less than 1 equivalent of iron (ferrous chloride or ferrous bromide) to the reactant by adding the salt dissolved in anhydrous ethanol. Slowly add the iron solution to the stirring ligand solution using a pipette and observe the formation of the complex by monitoring with a mass spectrometer. After about 1 day, add the remaining equivalent of iron salt and continue stirring until the amount of free ligand is observed to be less than 10% by mass spectrometry. If necessary, the ligand can be deprotonated by adding an ethanolic sodium hydroxide solution to induce the formation of the iron complex. The formation of the iron complex is identified by ESI-MS. ([M + ], L1A=481, L2A=561, L3A=525, L6A=497 ([ML]+H + ) L1B=435) [Example 10]

[0205] This embodiment describes the synthesis of the macrocyclic material of the present disclosure. In the following, L represents the neutral ligand in the mass spectral analysis.

[0206] Metallization of TOB half, Fe(TOB half): [ka] First, 30 mg of the above ligand (FW = 381.5 g / mol, 0.079 mmol) was dissolved in 2 mL of ethanol. This ligand solution was centrifuged to remove insoluble matter and then heated and stirred. Next, 8 mg of anhydrous ferrous chloride (FW = 126.75, 0.063 mmol) was dissolved in an additional 1.5 mL of ethanol and added to the ligand while stirring using a pipette. The following day, 260 μL of stock solution of ferrous chloride (0.06 M) was added to the solution to bring the total amount of iron to 0.085 mmol or 1.08 equivalents. The product was triturated with ether, isolated, and then dried to obtain a yellow solid. Mass spectrometry: 435.9[Fe(L-2H + )] + At 33°C, the proton relaxation ability of the compound was analyzed using 1.4T Benchtop NMR, and the r1 value was 1.7 mM. -1 s -1 Here, L is a neutral ligand.

[0207] Metallization of TOB2, Fe(TOB2): [ka] 36.3 mg of TOB2 oily substance (FW = 427 g / mol; 0.085 mmol) was dissolved in 3 mL of ethanol and stirred on a hot plate. Next, 17 mg of iron(II) chloride tetrahydrate (FW: 198.81; 0.085 mmol) was added. The reaction mixture was stirred overnight in heated ethanol. The next day, an additional 15 mg (0.075 mmol) was added to 1 mL of ethanol and stirred overnight. The following day, heating of the solution was stopped and a solid product was formed. This solid was triturated with diethyl ether. A yellow solid was obtained. ESI-MS: 481.5 [Fe(L-2H + ) + ]

[0208] Metallization of sulbot2, Fe(sulbot2): [ka] 30.2 mg of sulbot2 ligand (NH4) in 2 mL of ethanol + Salt was added from Dowex resin in the previous step. [NH4(L)] (FW = 524.6 g / mol, 0.058 mmol) was stirred and the mixture was set to heat and stir. Next, 10.8 mg of iron(II) chloride tetrahydrate (FW 198.81, 0.054 mmol) was dissolved in 2 mL of ethanol and added dropwise to the ligand while stirring. The next day, heating of the reaction mixture was stopped and it was stirred for a further 2 days. The solution was then collected and the white precipitate was removed by spin-down using a centrifuge. The solution was then triturated with diethyl ether, and the solid showing the target product was isolated by mass spectrometry (20.2 mg). MS: 561.4 [Fe(L-2H + ) + ] About 25% 583.3 [Fe(L-3H + )+Na + ] and 12% 508.6 [L+H + ]

[0209] Metallization of TOBA2, Fe(TOBA2): [ka] A 24 mg mass of ligand L3A (FW = 471.5 g / mol; 0.51 mmol) was dissolved in 2 mL of ethanol, and a minimum amount of water was added to solubilize the substance. Next, 1.5 equivalents of iron(II) chloride tetrahydrate (FW 198.81 g / mol, 15 mg) were added, and the mixture was heated and stirred. The precipitated yellow solid was collected, washed with diethyl ether, and dried. Mass spectrometry analysis confirmed the formation of the product. m / z = 525.3 [Fe(L-2H + ) + ]

[0210] Metallization of phenolTOB2, Fe(phenolTOB2): [ka] 35.6 mg of ligand (Fw = 443 g / mol; 0.0803 mmol) was dissolved in 3 mL of ethanol and stirred. Equimolar amounts of anhydrous ferric chloride (FW 162.204 g / mol, 13 mg) were added, and the reaction mixture was stirred under heating. While stirring the reaction mixture, 11 mg of potassium carbonate (FW 138.21 g, 0.0803 mmol) was added to make it basic. Once the conversion to the product was confirmed by mass spectrometry, the reaction was cooled to room temperature, and the compound was isolated by precipitation with diethyl ether. MS ESI m / z=497.7 [Fe(L-2H + ) + ] The complex was analyzed for proton water relaxation by 1.4T benchtop NMR (33°C, pH 7.0), and r1 = 1.2 ± 0.2 mM. -1 s -1 I obtained it.

[0211] While this disclosure has been described with reference to one or more specific embodiments, it will be understood that other embodiments of this disclosure are possible without departing from the scope of this disclosure.

Claims

1. It is a macrocyclic complex, - A large ring core having the following structure 【Chemistry 1】 Here R 1 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, wherein the substituted or unsubstituted alkyl group is not a methyl group. Z 1 , Z 2 , and Z 3 It is independently selected from one or more of the following pendant bases: 【Chemistry 2】 and their protonated species, partially deprotonated species, or deprotonated species, Here, Q 3 , Q 4 and Q 5 are each independently an anionic group or -H, -NR 2 , -NO 2 , -CN, -(CH 2 ) m NR 2 , OH, OR, -P(O)OH 2 , -(CH 2 ) m PO(OH) 2 , -SO 3 H, and are selected from their deprotonated species, where m is 1 or 2 and R is an alkyl group, CF 3 group, aryl group, alkyl carboxylate, or alkyl carboxylic acid; and, The macrocyclic complex has two of 1, 1', 2, 3, 4, 8, and 10, or a combination thereof, and not all pendant groups are the same, and • A high-spin Fe(III) cation, where the high-spin Fe(III) cation is complexed with the macrocyclic core of the macrocyclic compound and / or with at least one pendant group substituent. This includes, however, i) If two of the pendant bases are structures 1, 1', 2, 3, or any combination thereof, the third pendant base is not 1, 1', 2, or 3; ii) If two of the pendant bases are structures 1, 1', 2, 3, 8, 14, or any combination thereof, the third pendant base is not 1, 1', 2, 3, 8, or 14; iii) If two of the pendant groups are structures 1, 1', 2, 3, 10, or any combination thereof, and R of structure 1 and / or structure 1' is phenyl, then R 1 is not a substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl group; iv) The macrocyclic core does not have the following structure: 【Transformation 3】 【Chemistry 4】 【Transformation 5】 【Transformation 6】 【Transformation 7】 And, v) The macrocyclic complex does not have the following structure: 【Transformation 8】 【Chemistry 9】

2. The macrocyclic complex according to claim 1, wherein at least one or all of the pendant groups are covalently bonded to N on the macrocyclic core.

3. The macrocyclic complex according to claim 1, wherein the macrocyclic complex has at least one water or at least one hydroxide complexed with a high-spin Fe(III) cation.

4. Z 1 , Z 2 , and Z 3 However, the macrocyclic complex according to claim 1, independently selected from the following: 【Chemistry 10】 【Chemistry 11】 and their protonated, deprotonated, and partially deprotonated species (where applicable).

5. The macrocyclic complex according to claim 1, wherein the macrocyclic core has the following structure, and high-spin Fe(III) is complexed therein: 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 Or, their protonated, deprotonated, or partially deprotonated forms (if applicable).

6. The macrocyclic complex according to claim 1, wherein the macrocyclic complex has the following structure: 【Chemistry 16】 【Chemistry 17】 [Chemistry 18] 【Chemistry 19】 【Chemistry 20】 【Chemistry 21】 【Chemistry 22】 【Chemistry 23】 【Chemistry 24】 Or, their deprotonated species, partially deprotonated species, or protonated species (if applicable).

7. A composition comprising one or more macrocyclic complexes as described in claim 1.

8. The composition according to claim 7, further comprising human serum albumin and / or meglumine.

9. A method for obtaining images of cells, organs, vascular systems, and at least a portion of tissues: Contacting cells, organs, vascular systems, or tissues with one or more macrocyclic complexes according to claim 1, To image cells, organs, vascular systems, or at least a portion of tissue to obtain an image of cells, organs, vascular systems, or a portion of tissue. The method includes, where the image is obtained using magnetic resonance.

10. The method according to claim 9, wherein the cells, organs, vascular system, or tissues are part of an individual.

11. The method according to claim 9, wherein the aforementioned image is obtained using magnetic resonance imaging (MRI).

12. The macrocyclic complex is T 1 The method according to claim 9, which is an agent.

13. A macrocyclic complex having the following structure: 【Chemistry 25】 Here, the tri(hydroxy)butyl group and -(CH 2 ) n The R group is a pendant group, and each R is independently selected from the following: alkyl groups; aryl groups; heteroaryl groups; alkyl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; aryl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; heteroaryl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; and H; or salts, partial salts, hydrates, polymorphs, or stereoisomers thereof; n is 1, 2, or 3. Here, a high-spin Fe(III) cation is complexed with the macrocyclic core and / or at least one pendant group substituent of the macrocyclic compound. Macrocyclic complex.

14. The macrocyclic complex according to claim 13, further comprising a coordinating pendant group or a non-coordinating pendant group.

15. The macrocyclic complex according to claim 13, wherein at least one of the pendant groups is substituted at the benzyl position or with a carbon atom of an alkyl group connected to a heteroatom of the pendant group.

16. The pendant base is 【Chemistry 26】 And, selected from those protonated species, partially deprotonated species, and deprotonated species (if applicable), Q 3 Q 4 and Q 5 However, each is independently an anionic group, or -H, -NR 2 , -NO 2 -CN, -(CH 2 ) m NR 2 OH, OR, -CH 2 PO(OH) 2 ,-(CH 2 ) m P(O)(OH) 2 , -SO 3 H, and selected from their deprotonated species, partially deprotonated species, and protonated species (if applicable), The macrocyclic complex according to claim 13.

17. The macrocyclic complex according to claim 13, having at least one open coordination site.

18. The macrocyclic complex according to claim 13, having at least one water or at least one hydroxide complexed with a high-spin Fe(III) cation.

19. The macrocyclic complex according to claim 13 having the following structure: 【Chemistry 27】 【Chemistry 28】 Or, a protonated or deprotonated analog thereof, High-spin Fe(III) atoms are complexed.

20. The macrocyclic complex according to claim 13 having the following structure: 【Chemistry 29】 【Transformation 30】 【Chemistry 31】 Or, their protonated species, partially deprotonated species, or deprotonated species.

21. The macrocyclic complex according to claim 20 having the following structure: 【Chemistry 32】

22. A composition comprising one or more macrocyclic complexes according to claim 13 and a pharmaceutically acceptable carrier.

23. The composition according to claim 22, further comprising human serum albumin and / or meglumine.

24. A method for obtaining images of cells, organs, vascular systems, and at least a portion of tissues: Contacting cells, organs, vascular systems, or tissues with one or more macrocyclic complexes according to claim 13, To image cells, organs, vascular systems, or at least a portion of tissue to obtain an image of cells, organs, vascular systems, or a portion of tissue. The method includes, where the image is obtained using magnetic resonance.

25. The method according to claim 24, wherein the cells, organs, vascular system, or tissues are part of an individual.

26. The method according to claim 24, wherein the image is obtained using magnetic resonance imaging (MRI).

27. The macrocyclic complex is T 1 The method according to claim 24, which is an agent.

28. Macrocyclic compounds having the following structure: 【Transformation 33】 Here, the tri(hydroxy)butyl group and -(CH 2 ) n The R group is a pendant group, and each R is independently selected from the following: alkyl groups; aryl groups; heteroaryl groups; alkyl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; aryl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; heteroaryl groups comprising one or more -OH groups, one or more sulfonic acid groups, one or more carboxylic acid groups, one or more phosphonic acid groups, one or more alkyl groups, or a combination thereof; and H; or salts, partial salts, hydrates, polymorphs, or stereoisomers thereof; Here, n is 1, 2, or 3.

29. The macrocyclic compound according to claim 28, further comprising a coordinating pendant group or a non-coordinating pendant group.

30. The macrocyclic compound according to claim 28, wherein at least one of the pendant groups is substituted at the benzyl position or with any carbon of an alkyl group connected to a heteroatom of the pendant group.

31. The macrocyclic compound according to claim 28, wherein the pendant group is selected from the following: 【Transformation 34】 and their protonated species, partially deprotonated species, deprotonated species (if applicable), Q 3 Q 4、 and Q 5 Each of these is independently an anionic group, or -, -H, -NR 2 , -NO 2 -CN, -(CH 2 ) m NR 2 OH, OR, -CH 2 PO(OH) 2 ,-(CH 2 ) m P(O)(OH) 2 , -SO 3 H, and its deprotonated species, partially deprotonated species, and protonated species (if applicable) are selected.

32. The macrocyclic compound according to claim 28, having at least one open coordination site.

33. The macrocyclic compound according to claim 28 having the following structure: 【Chemistry 35】 【Transformation 36】 Or, their protonated species, partially deprotonated species, or deprotonated species.

Images