WO2021197283A1

WO2021197283A1 - Synthetic peptide amide compound and its use in the field of medicine

Info

Publication number: WO2021197283A1
Application number: PCT/CN2021/083706
Authority: WO
Inventors: Xiaoping Fu; Guoqing ZHONG; Haibo Zhou; Hai HU; Xi Hu; Jian Gao; Yuanbo LI; Yu Yuan
Original assignee: Chengdu Sintanovo Biotechnology Co., Ltd.
Priority date: 2020-04-03
Filing date: 2021-03-30
Publication date: 2021-10-07
Also published as: CN113493490A; CN113493490B

Abstract

The invention discloses a synthetic peptide amide compound, which belongs to the field of medicine, and specifically discloses a synthetic peptide amide compound containing a boronic acid group and a preparation method thereof. The invention also discloses use of the synthetic peptide amide compound in the manufacture of a medicament for preventing or treating various diseases associated with κ-opioid receptors.

Description

SYNTHETIC PEPTIDE AMIDE COMPOUND AND ITS USE IN THE FIELD OF MEDICINE

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Chinese Patent Application No. 202010258951.4, filed on April 03, 2020 and titled with “SYNTHETIC PEPTIDE AMIDE COMPOUND AND ITS USE IN THE FIELD OF MEDICINE” , and the disclosure of which is hereby incorporated by reference.

FIELD

The present invention relates to the field of medicine, in particular to a kind of synthetic peptide amide compounds, their preparation method thereof and their application in the field of medicine.

BACKGROUND

Opioid receptors are a major type of G protein-coupled receptors, which are the binding targets of endogenous opioid peptides and opioids. The activation of opioid receptors has a regulatory effect on the immunity of the nervous system and the endocrine system. It is currently the strongest and commonly used central analgesic. Endogenous opioid peptides are opioid active substances naturally produced in mammals. The currently known endogenous opioid peptides can be roughly divided into enkephalins, endorphins, dynorphins and neorphins. There are corresponding opioid receptors in the central nervous system, namely μ, δ and κ receptors. The μ receptor has the strongest analgesic activity, and the strongest addiction, which is the main cause of side effects. The δ receptor is less addictive, and its analgesic effect is not obvious. μ opioid receptor agonists such as morphine are the main drugs for clinical relief of severe pain, and are the most used powerful analgesic in the world. They are the most effective drugs for treating chronic arthritis, inflammatory neuralgia, postoperative pain, and moderate to severe pain caused by various cancers. However, systemic administration of traditional μ opioid analgesics can cause side effects, such as respiratory depression, drug addiction, constipation, nausea, confusion, and tolerance. Piperidines (pethidine, fentanyl, etc. ) are also μ opioid receptor agonists, which have the same pharmacological effects as morphine and the same clinical application as morphine. However, pethidine has less sedative and anesthetic effects, and has weaker respiratory depression than morphine, and has less adverse rections than morphine. Other common μ opioid receptor agonists include aminoketones (methadone, dextropropoxyphene) , cyclohexane derivatives (tramadol) , and aminotetralins (dazocine) . There are still many μ opioid receptor agonists in preclinical and clinical stages.

The κ-opioid receptor (KOR) consists of 380 amino acids, and dynorphin is its endogenous ligand. It is expressed in sensory neurons, dorsal root ganglion cells and the terminals of primary afferent neurons, and is related to major physiological activities such as pain, neuroendocrine, emotional behavior and cognition. κ-opioid receptor agonists do not cause respiratory depression and constipation, and are less addictive. Peripheral administration of opioid receptor agonists does not have any analgesic effect under normal conditions of the body. When there is inflammation or tissue damage, the function of peripheral opioid receptors is enhanced, and it exerts an analgesic effect after the administration of an opioid receptor agonist. In addition, the body is not easily tolerated by κ-opioid receptor agonists.

Patent WO2013184794 discloses a novel polypeptide κ-opioid receptor agonist. A tetrapeptide with D configuration amino acids is contained in the molecular structure, and has shown strong long-acting analgesic activity and less addiction in clinical trials. The clinical indications that have been initiated include: acute pain, uremic pruritus, pain after abdominal surgery, osteoarthritis, sciatic and musculoskeletal diseases, rheumatic diseases, postoperative pain, pruritus, chronic kidney disease and the like. Such peptide drugs have a brand-new mechanism of action, providing an improved treatment method for moderate to severe pain. However, clinical Phase III trials have shown that it can cause some side effects such as hypernatremia. Thus, it is still attractive to obtain new κ opioid receptor agonists with better activity, fewer side effects, and better druggability.

In summary, as drugs, κ opioid receptor agonists have the potential to treat drug addiction and have very good application prospects in the field of medicine. In order to achieve a better therapeutic effect to meet market demand, the inventors wish to develop a more efficient and low-toxic KOR agonist. The present invention provides a new kind of κ opioid receptor agonist compounds containing boronic acid structural fragments. Experimental tests have shown that this type of compounds have a very good therapeutic effect.

SUMMARY

In order to solve the above technical problems, the present invention provides a kind of synthetic peptide amide compounds. The synthetic peptide amide compounds, as a κ opioid receptor agonist, have better analgesic activity and fewer side effects. The invention also provides use of the synthetic peptide amide compounds in the field of medicine.

The present invention is carried out through the following technical solutions:

Provided is a kind of synthetic peptide amide compounds, having a structure as shown in general formula (I) :

or tautomers, mesomers, racemates, enantiomers, diastereomers or mixtures thereof, isotope derivatives, solvates, or metabolites thereof, prodrugs or pharmaceutically acceptable salt or ester thereof;

wherein n is any integer from 0 to 3;

R ¹, R ² are selected from hydrogen, alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, phthaloyl, p-toluenesulfonyl, o-nitrobenzenesulfonyl, p-nitrobenzenesulfonyl, t-butyloxycarboryl, benzyloxycarbonyl, 9-fluorenylmethyloxycarbonyl, allyloxycarbonyl, trimethylsilylethyloxycarbonyl, C1-C8 alkoxycarbonyl, C1-C8 acyl, trifluoroacetyl, arylformyl, trityl, benzyl, 2, 4-dimethoxybenzyl and p-methoxybenzyl, wherein the alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, or heteroarylalkyl is optionally substituted by one or more substituents selected from alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxy, ester group, boronic acid (borate) group, acylamino, mercapto, amidino and ureido, and the heterocycloalkyl or heteroaryl contains 1 to 3 heteroatoms selected from N, O, and S;

R ³, R ⁴, R ⁵, R ^a, R ^c, R ^e, and R ^g are each independently selected from hydrogen, halogen and C1-C10 alkyl;

R ^b, R ^d, R ^f, and R ^h are each selected from the following groups:

hydrogen, halogen, C1-C10 alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxyl, ester group, boronic acid (borate) group, acylamino, mercapto, amidino and ureido, wherein the alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl or alkynyl can be substituted by one or more substituents selected from alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxy, ester group, sulfonyl, sulfinyl, phosphoryl, phosphinyl, phosphate (phosphite) , boronic acid (borate) group, acylamino, mercapto, amidino and ureido, and the heterocycloalkyl or heteroaryl contains 1 to 3 heteroatoms selected from N, O, and S;

is an optionally substituted 3- to 8-membered heterocyclic moiety, wherein Y is selected from C, N, O and S; the heterocyclic moiety is selected from aromatic heterocyclic ring, non-aromatic heterocyclic ring, and corresponding bridged-ring, fused-ring and spiro-ring, which can be substituted by one or more substituents selected from hydroxyl, amino, C1-C10 alkyl, alkoxy, alkenyl, alkynyl, ester group, acylamino, halogen, nitro, cyano, and mercapto,

W is selected from C1-C10 alkylamino, cycloalkylamino, aromatic and non-aromatic heterocyclylamino, arylamino, arylalkylamino, aromatic and non-aromatic heterocyclylalkylamino, 3-8-membered aromatic heterocyclic ring and non-aromatic heterocyclic ring, and bridged-ring, fused-ring and spiro-ring containing the heterocyclic ring; the aromatic heterocyclic ring or non-aromatic heterocyclic ring, bridged-ring, fused-ring or spiro-ring contains 1 to 3 heteroatoms optionally selected from N, O, and S, and contains at least 1 N atom;

wherein 1 N atom in W is directly connected to the carbonyl on the left side of the structural formula to form an amide bond;

B (OR ⁶) ₂ is directly connected to the atom on the heterocyclic ring in W, or is connected to the atom on the substituent of the heterocyclic ring;

B (OR ⁶) ₂ is selected from any of the following structures, and a part of atoms in two R ⁶ groups are connected to form a cyclic substituent:

In general formula (I) , R ¹ together with one or more atoms of R ², R ^a, and R ^b forms a ring having any of the following structures:

In general formula (I) , R ^b, R ^d, R ^f, and R ^h are independently selected from C1-C10 alkyl and the following structures:

the C1-C10 alkyl or the above-mentioned structure is optionally substituted by one or more substituents selected from halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, amino, hydroxyl, cyano, nitro, acylamino, ester group, sulfonyl, sulfinyl, phosphoryl, phosphinyl, sulfonate (sulfinate) , phosphate (phosphite) , boronic acid (borate) group, 3-10 membered heterocyclyl, C1-C10 cycloalkyl, C6-C14 aryl, and C5-C15 heteroaryl;

A and E are independently selected from NH, O, S and Se; and

n ₁, n ₂, n ₃, n ₄, and n ₅ are selected from any integer from 0 to 8.

moiety is selected from any of the following structures:

wherein m, m ₁, m ₂, m ₃ and m ₄ are any integers from 0 to 6.

Preferably, the invention provides a kind of synthetic peptide amide compounds having a structure as shown in general formula (II) :

wherein W is -W ₁-W ₂-; W ₁ is a 3-8-membered aromatic or non-aromatic nitrogen-containing heterocyclic group, or bridged-ring, fused-ring or spiro-ring containing the nitrogen-containing heterocyclic group, and N is connected to carbonyl; W ₂ is selected from C1-C10 alkyl, C1-C10 alkylamino, vinyl and ethynyl;

or W is -NH-W ₃-, and NH is connected to carbonyl; W ₃ is selected from C1-C10 alkyl, C3-C10 cycloalkyl, C6-C10 aryl, 3-8 membered aromatic or non-aromatic heterocyclic group, arylalkyl, and heterocyclylalkyl.

The scope of R ⁶ is the same as above, and will not be repeated here.

Preferably, general formula (II) includes but is not limited to compounds of the following structures, or tautomers, mesomers, racemates, enantiomers, diastereomers or mixtures thereof, isotope derivatives, solvates, or metabolites thereof, prodrugs or pharmaceutically acceptable salt or ester thereof;

Compound 1: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) pyrrolin-3-yl) boronic acid

Compound 2: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-4-yl) boronic acid

Compound 3: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -2, 5-dihydro-1H-pyrrol-3-yl) boronic acid

Compound 4: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -1, 2, 3, 6-tetrahydropyridin-4-yl) boronic acid

Compound 5: (2- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) ethyl) boronic acid

Compound 6: (4- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) cyclohexyl) boronic acid

Compound 7: (4- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) phenyl) boronic acid

Compound 8: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) 1, 2, 3, 6-tetrahydropyridin-3-yl) boronic acid

Compound 9: (7- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -7-azaspiro [3.5] non-2-yl) boronic acid

Compound 10: (3- ( (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) methyl) phenyl) boronic acid

Compound 11: ( (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-4-ylidene) methyl) boronic acid

Compound 12: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-3-yl) boronic acid

In another aspect, the present invention provides a pharmaceutical composition comprising the compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs or pharmaceutically acceptable salts or esters thereof, and one or more pharmaceutically acceptable carriers and/or excipients.

Specifically, the present invention provides a pharmaceutical composition comprising the above-mentioned synthetic peptide amide compound, and a pharmaceutically acceptable carrier, excipient, diluent, adjuvant, medium, or a combination thereof.

In another aspect, the present invention provides use of the compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs or pharmaceutically acceptable salts or esters thereof, or the pharmaceutical composition comprising the compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs, or pharmaceutically acceptable salts or esters thereof in the preparation of a medicament for the prevention or treatment of various diseases or conditions associated with κ-opioid receptor in mammals.

In another aspect, the present invention provides a compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs or pharmaceutically acceptable salts or esters thereof, or a pharmaceutical composition comprising the compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs, or pharmaceutically acceptable salts or esters thereof, for use in the prevention or treatment of various diseases associated with κ-opioid receptor in mammals.

In another aspect, the present invention provides a method for preventing or treating diseases associated with κ-opioid receptor in mammals, comprising administering a therapeutically effective amount of a compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs, or pharmaceutically acceptable salts or esters thereof, or a pharmaceutical composition comprising the compound represented by general formula (I) or (II) or stereoisomers, solvates, metabolites, prodrugs, or pharmaceutically acceptable salts or esters thereof to mammals in need.

In a preferred embodiment of the present invention, the various diseases associated with κ-opioid receptor are selected from pain, inflammation, pruritus, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma.

In a preferred embodiment of the present invention, the pain is selected from neuropathic pain, somatic pain, visceral pain, skin pain, arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, dyspepsia, post-surgical pain, pain after medical treatment, headache, toothache, cervical pain, eye pain, otitis pain, chest pain, abdominal pain, low back and leg pain, gout, rheumatism, rheumatoid, cancer pain and pain associated with gastrointestinal dysfunction and the like.

As used herein, “alkyl” , when used alone or in combination with other groups, represents a saturated linear or branched group containing 1-12, preferably 1-8, more preferably 1-6 and even more preferably 1-4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, n-pentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, n-decyl, etc.

As used herein, “alkenyl” , when used alone or in combination with other groups, represents a linear or branched group containing 2-12, preferably 2-8, more preferably 2-6 and even more preferably 2-4 carbon atoms and an unsaturated double bond, including linear or branched diene, for example: vinyl, allyl, 1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 5-heptenyl, 6-heptenyl, 1, 3-butadiene, 1, 3-pentadiene, 2-methyl-1, 3-butadiene, etc.

As used herein, “alkynyl” , when used alone or in combination with other groups, a linear or branched group containing 2-12, preferably 2-8, more preferably 2-6 and even more preferably 2-4 carbon atoms and an unsaturated triple bond, for example: ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, linear or branched diynes or triynes, such as 1, 3-butadiyne, etc., which may be further substituted with aryl.

As used herein, “cycloalkyl” , when used alone or in combination with other groups, represents a 3-7, preferably 3-6, and more preferably 3-5 membered carbocyclic group, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.

As used herein, “aryl” , when used alone or in combination with other groups, refers to an optionally substituted aromatic carbocyclic group containing 1, 2 or 3 rings, containing 6-14, preferably 6-10 carbon atoms, which are connected by a bond or in a fused way, for example: phenyl, biphenyl, naphthyl, tetrahydronaphthalene, dihydroindene, which can be further substituted by other aryl or aryl-containing substituents.

As used herein, “heterocyclic group” , when used alone or in combination with other groups, represents an optionally substituted a 3-7, preferably a 3-6 membered cyclic group containing more than one heteroatom, which is selected from N, S and O. This group includes saturated, partially saturated and aromatic unsaturated heterocyclic groups. Saturated heterocyclic groups are equivalent to the term “heterocycloalkyl” herein, when used alone or in combination with other groups, include the following examples: aziridinyl, azetidinyl, tetrahydrofuranyl, tetrahydrothienyl, oxazolidinyl, thiazolidinyl, benzothiazolyl, pyrrolidinyl, imidazolidinyl, piperidinyl, piperazinyl, thiazinyl, 2-oxopiperidinyl, 4-oxopiperidinyl, 2-oxopiperazinyl, 3-oxopiperazinyl, morpholinyl, thiomorpholinyl, 2-oxomorpholinyl, azepinyl, diazapinyl, oxapinyl, thiapinyl, etc., 1-3-oxanyl, etc. The partially saturated heterocyclic group is equivalent to the term “heterocyclenyl” herein, when used alone or in combination with other groups, includes the following examples: dihydrothienyl, dihydropyranyl, dihydrofuranyl, dihydrothiazolyl, etc. The aromatic unsaturated heterocyclic group is equivalent to the term “heteroaryl” herein, when used alone or in combination with other groups, can be a monocyclic ring, and can also be a bonded or fused polycyclic ring, which includes the following examples: thiazolyl, oxazolyl, imidazolyl, isoxazolyl, pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, thienyl, furyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolyl, quinolinyl, isoquinolinyl, quinoxalinyl, bipyridyl, acridinyl, phenanthridinyl, phenanthrolinyl, quinazolonyl, benzimidazolyl, benzofuranyl, benzothienyl, benzothiazolyl, benzoxazolyl, benzisoxazolyl, bipyridyl, biphenylpyridyl.

Herein, unless otherwise specified, “heteroalkyl” and “heterocyclic group” contain one or more heteroatoms, preferably 1-6, more preferably 1, 2, or 3. When the groups contain multiple heteroatoms, the multiple heteroatoms may be the same or different.

“Halogen” , when used alone or in combination with other groups, such as forming “haloalkyl” , “perhaloalkyl” , etc., refers to fluorine, chlorine, bromine or iodine. The term “haloalkyl” represents alkyl as defined above substituted by one or more halogens, including perhaloalkyl, such as fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl, difluoroethyl, trifluoromethyl, etc. The term “haloalkoxy” represents haloalkyl as defined above, which is directly connected to an oxygen atom, such as fluoromethoxy, chloromethoxy, fluoroethoxy, chloroethoxy, etc.

“Acyl” , when used alone or in combination with other groups, includes the following forms: -C (=O) H, -C (=O) -alkyl, -C (=O) -aryl, -C (=O) -aralkyl and -C (=O) -heteroaryl, such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, hexanoyl, heptanoyl, benzoyl, etc. The non-C (=O) - part in the acyl may be substituted with optional substituents, including but not limited to halogen, lower alkyl (C1-C4 alkyl) , aryl or aryl-containing substituents.

“Ester group” , when used alone or in combination with other groups, it represents the -COO- group, including: alkoxycarbonyl, such as methoxycarbonyl, ethoxycarbonyl, etc.; aryloxycarbonyl, such as phenoxycarbonyl, naphthoxycarbonyl, etc.; aralkyloxycarbonyl, such as benzyloxycarbonyl, phenethoxycarbonyl, naphthylmethoxycarbonyl; heterocyclyloxycarbonyl, wherein heterocyclyl is defined as above; the non-COO- part of the ester group may be further substituted with optional substituents.

As used herein, a compound or chemical moiety being described with “substituted” means that at least one hydrogen atom of the compound or chemical moiety is replaced by a second chemical moiety. Non-limiting examples of substituents are those present in the exemplary compounds and embodiments as disclosed herein, deuterium, fluorine, chlorine, bromine, iodine; hydroxyl, oxo; amino (primary, secondary, tertiary) , imino, nitro, nitroso; cyano, isocyano, alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, alkenyl, cycloalkenyl, alkynyl; lower alkoxy, aryloxy; mercapto, thioether; phosphine; carboxyl, sulfonato, phosphono; acyl, thiocarbonyl, sulfonyl; amide, sulfonamide; ketone; aldehyde; ester, sulfonate; haloalkyl (for example, difluoromethyl, trifluoromethyl) ; monocyclic or fused or non-fused polycyclic carbocycloalkyl (for example, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl ) ; or monocyclic or fused or non-fused polycyclic heterocycloalkyl (for example, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl or thiazinyl) ; or a monocyclic or fused or non-fused polycyclic carbocyclic or heterocyclic aryl (e.g., phenyl, naphthyl, thiazolyl, oxazolyl, imidazolyl, isoxazolyl, pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, thienyl, furyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolyl, quinolinyl, isoquinolinyl, quinoxalinyl, bipyridyl, acridinyl, phenanthridinyl, phenanthrolinyl, quinazolonyl, benzimidazolyl, benzofuranyl, benzothienyl, benzothiazolyl, benzoxazolyl, benzisoxazolyl) ; or aryl-lower alkyl; -CHO; -CO (alkyl) ; -CO (aryl) ; -CO ₂ (alkyl) ; -CO ₂ (aryl) ; -CONH ₂; -SO ₂NH ₂; -OCH ₂CONH ₂; -OCHF ₂; -OCF ₃; -CF ₃; -NH ₂; -NH (alkyl) ; -N (alkyl) ₂; -NH (aryl) ; -N (alkyl) (aryl) ; -N (aryl) ₂. In addition, when the substituent is oxygen, it means that two hydrogen atoms on the same or different carbons are substituted by the same oxygen atom to form a carbonyl or cyclic ether, such as ketone carbonyl, aldehyde carbonyl, ester carbonyl, amide carbonyl, ethylene oxide, etc. In addition, these parts can also be optionally substituted by fused ring structures or bridges (for example, -OCH ₂O-) . In the present invention, they can preferably be substituted by one, two, three, four, five or six substituents which are independently selected from halogen, alkyl, alkoxy, aryl, aryloxy, and -N (aryl) ₂, or substituted by perhalogen, such as trifluoromethyl, perfluorophenyl. When the substituents contain hydrogen, these substituents may be optionally further substituted by substituents selected from such groups.

The meanings of the abbreviations of the materials used in the present invention were shown in Table 1:

The present invention designs and synthesizes a series of new polypeptide derivatives containing boric acid structural fragments. Boron-containing compounds have subtle characteristics and can reversibly interact with protein targets. Polypeptide derivatives obtained by binding boronic acid groups to polypeptides, as a κ opioid receptor agonist drug, have better analgesic activity; and because the boronic acid group has unique characteristics of large polarity and water solubility, the brain permeability will be lower, so there are fewer side effects.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described here are used to provide a further understanding of the embodiments of the present invention. The drawings constitute a part of the application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:

Figure 1 shows the synthesis scheme of target compound 1;

Figure 2 shows the synthesis scheme of target compound 6.

DETAILED DESCRIPTION

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with examples. The exemplary embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

Example 1 Synthesis of compound 1: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) pyrrolin-3-yl) boronic acid

As shown in Figure 1, the synthesis of compound 1 can be prepared by the following process steps: Step 1: Synthesis of intermediate 1-1

2-CTC Resin (degree of substitution was 0.993mmol/g, 2.012g) was swelled using DCM (20 mL) at room temperature for 15 min, and the solvent was removed. The mixed solution of 4- (tert-butoxycarbonylamino) -1-fluorenylmethoxycarbonylpiperidine-4-carboxylic acid (1.118 g, 2.4 mmol) and DIEA (0.516 g, 4.0 mmol) in DCM (15 mL) was added to the swollen resin and the mixture was reacted at room temperature for 2 h; then methanol (2 mL) and DIEA (1 mL) were added to continue the reaction for 0.5 h. The solvent was removed until dryness and the resulting mixture was washed with DCM (30 mL) for three times, and finally washed with DMF (30 mL) for three times, and the resin was directly put into the next reaction.

Step 2: Synthesis of intermediate 1-2

Piperidine/DMF (V/V=1/4, 20 mL) was added to the product obtained in step 1, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness. Piperidine/DMF (V/V= 1/4, 20 mL) was added again, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness, and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral; Fmoc-D-Lys (Boc) -OH (1.820g, 4.0 mmol) , HOBT (0.543 g, 4.0 mmol) and HBTU (1.521 g, 4.0 mmol) were added to DMF (20 mL) under ice bath conditions for activation for 10 min, and then DIEA (0.780 g, 6 mmol) was added and the mixture was reacted for 5 min. Finally, the activation solution was added to the resin and the mixture was reacted at room temperature for 2 h. The resin was treated with 5% ninhydrin solution (heated at 100℃ for 10 min) and the color did not change. The solution was removed until dryness and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral. After removing solvent until dryness, the resulting mixture was directly used in the next reaction.

Step 3: Synthesis of intermediate 1-3

Piperidine/DMF (V/V=1/4, 20 mL) was added to the product obtained in step 2, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness. Piperidine/DMF (V/V= 1/4, 20 mL) was added again, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness, and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral; Fmoc-D-Leu-OH (1.809g, 4.0 mmol) , HOBT (0.543 g, 4.0 mmol) and HBTU (1.521 g, 4.0 mmol) were added to DMF (20 mL) under ice bath conditions for activation for 10 min, and then DIEA (0.780 g, 6 mmol) was added and the mixture was reacted for 5 min. Finally, the activation solution was added to the resin and the mixture was reacted at room temperature for 2 h. The resin was treated with 5% ninhydrin solution (heated at 100℃ for 10 min) and the color did not change. The solution was removed until dryness and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral. After removing solvent until dryness, the resulting mixture was directly used in the next reaction.

Step 4: Synthesis of intermediate 1-4

Piperidine/DMF (V/V=1/4, 20 mL) was added to the product obtained in step 3, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness. Piperidine/DMF (V/V= 1/4, 20 mL) was added again, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness, and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral; Fmoc-D-Phe-OH (1.547 g, 4.0 mmol) , HOBT (0.543 g, 4.0 mmol) and HBTU (1.521 g, 4.0 mmol) were added to DMF (20 mL) under ice bath conditions for activation for 10 min, and then DIEA (0.780 g, 6 mmol) was added and the mixture was reacted for 5 min. Finally, the activation solution was added to the resin and the mixture was reacted at room temperature for 2 h. The resin was treated with 5% ninhydrin solution (heated at 100℃ for 10 min) and the color did not change. The solution was removed until dryness and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral. After removing solvent until dryness, the resulting mixture was directly used in the next reaction.

Step 5: Synthesis of intermediate 1-5

Piperidine/DMF (V/V=1/4, 20 mL) was added to the product obtained in step 4, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness. Piperidine/DMF (V/V= 1/4, 20 mL) was added again, and the mixture was reacted for 10 min at room temperature, and then removed of solvent until dryness, and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral; Boc-D-Phe-OH (1.547 g, 4.0 mmol) , HOBT (0.543 g, 4.0 mmol) and HBTU (1.521 g, 4.0 mmol) were added to DMF (20 mL) under ice bath conditions for activation for 10 min, and then DIEA (0.780 g, 6 mmol) was added and the mixture was reacted for 5 min. Finally, the activation solution was added to the resin and the mixture was reacted at room temperature for 2 h. The resin was treated with 5% ninhydrin solution (heated at 100℃ for 10 min) and the color did not change. The solution was removed until dryness and washed with DMF (30 mL) for 5 times. After the last washing, the pH of the waste liquid was tested to be neutral. After removing solvent until dryness, the resulting mixture was directly used in the next reaction.

Step 6: Synthesis of intermediate 1

1-5 (4.20 g) was added to trifluoroethanol/DCM (50 mL, V=/V=1/4) at room temperature, and the mixture was reacted for 2 h at room temperature. The resulting mixture was filtered with suction, and washed twice with DCM (30 mL) , and the organic phase was concentrated to about 5 mL. The concentrated solution was added dropwise to 100 mL of methyl tert-butyl ether and the mixture was stirred and settled to obtain intermediate 1 (2.103 g, purity 92.3%) .

ESI-MS (m/z) : 980.6 (M+H ⁺)

Step 7: Synthesis of intermediate 2

TFA (2 mL) was added dropwise to a solution of 1-N-tert-butoxycarbonylpyrrole-4-boronic acid pinacol ester (0.350 g, 1.1 mmol) in DCM (4 mL) , and the mixture was stirred at room temperature for 0.5 h. TLC showed that the reaction was completed. The mixture was concentrated under reduced pressure to obtain a transparent oil (trifluoroacetate of intermediate 2) , which was directly used for the next reaction.

Step 8: Synthesis of intermediate 3

A solution of intermediate 1 (0.980 g, 1.0 mmol) , HOBT (0.203 g, 1.5 mmol) , HBTU (0.569 g, 1.58 mmol) , DIEA (0.388 g, 3.0 mmol) in DCM (20 mL) was stirred at room temperature for 0.5 h, and then a crude product of the above intermediate 2 was added. The mixture was reacted at room temperature for 2 hours. The reaction solution was washed with saturated ammonium chloride solution, water and saturated brine respectively, and dried over anhydrous sodium sulfate. After filtration and concentration, the crude product was purified by Prep-HPLC to obtain 450 mg of target compound 3, with a purity of 93.5%.

ESI-MS (m/z) : 1159.7 (M+H ⁺)

Step 9: Synthesis of compound 1

TFA (5 mL) was added dropwise to the solution of intermediate 3 in DCM (10 mL) and the mixture was stirred at room temperature for 1 h. After concentration to dryness, the crude product was purified by Prep-HPLC to obtain 213 mg of trifluoroacetate of target compound 1, with a purity of 98%.

ESI-MS (m/z) : 777.5 (M+H ⁺)

¹H NMR (400 MHz, DMSO-d ₆+D ₂O) : δ 7.47–6.86 (m, 10H) , 4.80–4.50 (m, 2H) , 4.27 (d, J = 33.7 Hz, 2H) , 3.59 (s, 3H) , 3.32 (d, J = 53.1 Hz, 4H) , 3.06–2.83 (m, 3H) , 2.81–2.64 (m, 3H) , 2.42 –1.69 (m, 6H) , 1.67–1.09 (m, 11H) , 0.89-0.83 (m, 6H) .

Example 2 Synthesis of compound 2: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-4-yl) boronic acid

Compound 2 was prepared as described in Example 1, except that the raw material of borate was 1-N-tert-butoxycarbonylpiperidine-4-boronic acid pinacol ester.

ESI-MS (m/z) : 791.5 (M+H ⁺) ;

1H NMR (400 MHz, DMSO-d ₆+D ₂O) : δ 7.35–7.11 (m, 10H) , 4.61-4.58 (m, 2H) , 4.16 (d, J = 130.5 Hz, 3H) , 3.41 (d, J=11.4 Hz, 1H) , 3.06-2.90 (m, 5H) , 2.86–2.64 (m, 4H) , 2.44-2.31 (m, 1H) , 2.29-1.91 (m, 2H) , 1.82 (d, J = 14.2 Hz, 2H) , 1.76–0.93 (m, 16H) , 0.88-0.83 (m, 6H) .

Example 3 Synthesis of compound 3: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -2, 5-dihydro-1H- pyrrol-3-yl) boronic acid

Compound 3 was prepared as described in Example 1, except that the raw material of borate was 1-tert-butoxycarbonyl-2, 5-dihydro-1H-pyrrole-3-boronic acid pinacol ester.

ESI-MS (m/z) : 775.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆) δ 8.79-8.77 (m, 1H) , 8.51 (s, 2H) , 8.33-8.29 (m, 1H) , 8.03 (s, 3H) , 7.78-7.71 (m, 4H) , δ 7.34–7.14 (m, 10H) , 6.33 (s, 1H) , 4.73–4.55 (m, 2H) , 4.37-4.27 (m, 2H) , 4.25–3.94 (m, 3H) , 3.64–3.33 (m, 3H) , 3.12-2.89 (m, 4H) , 2.83–2.68 (m, 3H) , 2.17-2.06 (m, 3H) , 1.89-1.77 (m, 2H) , 1.66–1.21 (m, 9H) , 0.89-0.85 (m, 6H) .

Example 4 Synthesis of compound 4: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -1, 2, 3, 6-tetrahydropyridin-4-yl) boronic acid

Compound 4 was prepared as described in Example 1, except that the raw material of borate was N-Boc-1, 2, 5, 6-tetrahydropyridine-4-boronic acid pinacol ester.

ESI-MS (m/z) : 789.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆) δ 7.34–7.14 (m, 10H) , 6.33 (s, 1H) , 4.75 – 4.55 (m, 2H) , 4.50-4.23 (m, 2H) , 4.23 – 3.88 (m, 4H) , 3.63 – 3.33 (m, 3H) , 3.12-2.89 (m, 4H) , 2.83 – 2.69 (m, 3H) , 2.44 –1.96 (m, 4H) , 1.89-1.77 (m, 2H) , 1.66 – 1.21 (m, 9H) , 0.89-0.85 (m, 6H) .

Example 5 Synthesis of compound 5: (2- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) ethyl) boronic acid

Compound 5 was prepared as described in Example 1, except that the raw material of borate was 2- (Boc-amino) ethyl borate pinacol ester.

ESI-MS (m/z) : 751.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆+D ₂O) : δ 7.38 – 7.08 (m, 10H) , 4.77 – 4.53 (m, 2H) , 4.31 (s, 1H) , 3.97 (d, J = 5.3 Hz, 1H) , 3.80 – 3.35 (m, 3H) , 3.27 – 2.88 (m, 6H) , 2.83 – 2.65 (m, 3H) , 2.17 –1.95 (m, 2H) , 1.75 (s, 2H) , 1.66 – 1.36 (m, 7H) , 1.28 (d, J = 7.8 Hz, 2H) , 0.89-0.82 (m, 8H) .

Example 6 Synthesis of compound 6: (4- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) cyclohexyl) boronic acid

Step 1: Synthesis of intermediate 4-1

DIC (0.133 g, 1.05 mmol) , DMAP (0.012 g, 0.1 mmol) , N-hydroxyphthalimide (0.202 g, 1.2 mmol) were added to a solution of 4- (tert-butoxycarbonylamino) cyclohexane carboxylic acid (0.243 g, 1.0 mmol) in DCM (8 mL) at room temperature and the mixture was stirred at room temperature for 2 h. The reaction solution was diluted with 20 mL DCM and respectively washed with 1N HCl and water twice. The obtained mixture was dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a white solid 4-1 (0.545 g) , which was directly used in the next reaction.

ESI-MS (m/z) : 389.2 (M+H ⁺)

Step 2: Synthesis of intermediate 4-2

Reaction flask A: Under the protection of nitrogen at 0℃, MeLi (1.6M, 2 mL, 3eq) was slowly added to a solution of bis (pinacolato) diboron (0.838 g, 3.3 mmol) in anhydrous THF (4 mL) . After addition, the mixture was continued to be stirred at 0℃ for 0.5 h, and then at room temperature for 0.5 h.

Reaction flask B: 4-1 (0.189 g) and magnesium bromide diethyl ether complex (0.258 g, 1.0 eq) were dissolved in anhydrous THF (4 mL) under nitrogen protection at 0℃, and then nickel chloride hexahydrate (0.024 g, 0.1eq) , 4, 4'-dimethoxy-2, 2'-bipyridine (0.028 g, 0.13 eq) and anhydrous THF (4 mL) were added with stirring for 0.5 h until the reaction system turned pale green.

The solution in reaction flask A was one-time added to reaction flask B at 0℃, and the reaction system turns brown. The mixture was stirred at 0℃ for 1 h, and then warmed to room temperature and stirred for 1 h. The reaction mixture was added to 20 mL of saturated ammonium chloride solution, and the mixture was stirred for 10 min. 25 mL of ethyl acetate was added for extraction, and the aqueous phase was extracted with 15 mL of ethyl acetate; the combined organic phase was washed with saturated sodium chloride solution twice, dried over anhydrous sodium sulfate, filtered and concentrated to obtain 0.750 g crude product; the crude product was purified by column chromatography to obtain 0.150 g of transparent oily substance.

ESI-MS (m/z) : 326.2 (M+H ⁺)

Step 3: Synthesis of intermediate 4

4-2 (0.047 g, 0.145 mmol) was added to DCM (2 mL) , and then TFA (1 mL) was added. The mixture was stirred at room temperature for 0.5 h and then concentrated to dryness to obtain transparent oily substance (trifluoroacetate of intermediate 4) , which was directly used in the next reaction.

ESI-MS (m/z) : 226.2 (M+H ⁺)

Step 4: Synthesis of intermediate 5

A solution of intermediate 1 (0.100 g, 0.132 mmol) , HOBT (0.027 g, 0.198 mmol) , HBTU (0.75 g, 0.198 mmol) , DIEA (0.055 g, 0.396 mmol) in DCM (7 mL) was stirred at room temperature for 0.5 h, and then a crude product of the above intermediate 2 was added. The mixture was reacted at room temperature for 2 hours. The reaction solution was washed with saturated ammonium chloride solution, water and saturated brine respectively, and dried over anhydrous sodium sulfate. After filtration and concentration, the crude product was purified by Prep-HPLC to obtain 30 mg of compound 5.

ESI-MS (m/z) : 1187.7 (M+H ⁺)

Step 5: Synthesis of intermediate 6

TFA (2 mL) was added dropwise to the solution of compound 5 in DCM (4 mL) and the mixture was stirred at room temperature for 1 h. After concentration to dryness, the crude product was purified by Prep-HPLC to obtain 11 mg of trifluoroacetate of compound 6, with a purity of 98%.

ESI-MS (m/z) : 805.5 (M+H ⁺)

1H NMR (400 MHz, MeOD) δ 7.39 – 7.24 (m, 10H) , 4.88-4.73 (m, 1H) , 4.44-4.40 m, 2H) , 4.11-4.10 (m, 2H) , 3.83-3.81 (m, 1H) , 3.76 – 3.59 (m, 1H) , 3.59 – 3.43 (m, 1H) , 3.31 – 3.06 (m, 3H) , 3.04 – 2.89 (m, 4H) , 2.49-2.25 (m, 2H) , 1.96-1.91 (m, 3H) , 1.84 – 1.61 (m, 10H) , 1.57-1.44 (m, 3H) , 1.36 – 1.22 (m, 2H) , 1.02-0.96 (m, 6H) .

Example 7 Synthesis of compound 7: (4- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) phenyl) boronic acid

Compound 7 was prepared as described in Example 1, except that the raw material of borate was 4-aminophenylboronic acid pinacol ester.

ESI-MS (m/z) : 799.3 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆+D ₂O) : δ 7.90-7.65 (m, 4H) , 7.35–7.10 (m, 10H) , 4.51-4.48 (m, 2H) , 4.12 (d, J = 130.5 Hz, 3H) , 3.33 (d, J=11.2 Hz, 1H) , 3.00-2.29 (m, 5H) , 2.85–2.60 (m, 4H) , 2.44-2.32 (m, 1H) , 2.27-1.92 (m, 2H) , 1.80 (d, J = 14.1 Hz, 2H) , 1.73–0.90 (m, 16H) , 0.88-0.83 (m, 6H) .

Example 8 Synthesis of compound 8: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) 1, 2, 3, 6-tetrahydropyridin-3-yl) boronic acid

Compound 8 was prepared as described in Example 1, except that the raw material of borate was 1-tert-butoxycarbonyl-3, 6-dihydro-2H-pyridine-5-boronic acid pinacol ester.

ESI-MS (m/z) : 789.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆) δ 8.86 – 8.72 (m, 1H) , 8.49 (s, 3H) , 8.03 (s, 3H) , 7.80 (s, 4H) , 7.37 – 7.19 (m, 10H) , 6.55 (s, 1H) , 4.76 – 4.61 (m, 2H) , 4.46 – 3.91 (m, 10H) , 3.54 – 3.35 (m, 2H) , 3.19 –2.91 (m, 4H) , 2.83 – 2.75 (m, 2H) , 2.31-2.16 (m, 2H) , 1.97 – 1.76 (m, 2H) , 1.70 – 1.50 (m, 5H) , 1.50 – 1.42 (m, 2H) , 1.39 – 1.26 (m, 2H) , 0.96 – 0.78 (m, 6H) .

Example 9 Synthesis of compound 9: (7- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) -7-azaspiro [3.5] non-2-yl) boronic acid

Compound 9 was prepared as described in Example 6, except that the raw material of carboxylic acid was 7- (tert-butoxycarbonyl) -7-azaspiro [3.5] nonane-2-carboxylic acid.

ESI-MS (m/z) : 831.3 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆+D ₂O) : δ 7.90-7.65 (m, 4H) , 7.35–7.10 (m, 10H) , 4.51-4.48 (m, 2H) , 4.12 (d, J = 130.5 Hz, 3H) , 3.33 (d, J=11.2 Hz, 1H) , 3.00-2.29 (m, 5H) , 2.85–2.60 (m, 4H) , 2.44-2.32 (m, 1H) , 2.27-1.92 (m, 2H) , 1.80 (d, J = 14.1 Hz, 2H) , 1.73–0.90 (m, 16H) , 1.66-1.54 (m, 4H) , 0.88-0.83 (m, 6H) .

Example 10 Synthesis of compound 10: (3- ( (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acylamino) methyl) phenyl) boronic acid

Compound 10 was prepared as described in Example 1, except that the raw material of borate was tert-butyl 3- (4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) benzyl carbamate.

ESI-MS (m/z) : 813.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆+D ₂O) δ 9.05 – 8.70 (m, 2H) , 8.60 – 8.43 (m, 3H) , 8.20-8.01 (M, 5H) , 7.69 (s, 2H) , 7.37 – 7.17 (m, 12H) , 4.77 – 4.60 (m, 2H) , 4.46 – 4.12 (m, 4H) , 4.07 – 3.99 (m, 1H) , 3.802-3.79 (m, 2H) , 3.12-3.05 (m, 3H) , 2.95-2.90 (m, 1H) , 2.86 – 2.70 (m, 3H) , 2.20-2.12 (m, 2H) , 1.84-1.81 (m, 2H) , 1.71 – 1.42 (m, 7H) , 1.38 – 1.26 (m, 2H) , 0.96 – 0.79 (m, 6H) .

Example 11 Synthesis of compound 11: ( (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-4-ylidene) methyl) boronic acid

Compound 11 was prepared as described in Example 1, except that the raw material of borate was tert-butyl 4- [ (4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) methylene] pyridine-1-formate.

ESI-MS (m/z) : 803.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆+D ₂O) 8.83 – 8.70 (m, 1H) , 8.51 (s, 2H) , 8.42 – 8.30 (m, 1H) , 8.25 (s, 1H) , 8.02 (s, 3H) , 7.74 (s, 4H) , 7.36 – 7.12 (m, 10H) , 5.12 (s, 1H) , 4.77 – 4.56 (m, 2H) , 4.43 – 4.24 (m, 2H) , 4.21 – 3.90 (m, 2H) , 3.64 – 3.33 (m, 5H) , 3.16 – 2.85 (m, 4H) , 2.84 – 2.65 (m, 3H) , 2.38 –2.00 (m, 4H) , 1.97 – 1.77 (m, 2H) , 1.66 – 1.22 (m, 9H) , 0.96 – 0.73 (m, 6H) .

Example 12 Synthesis of compound 12: (1- (1- (D-Phe-D-Phe-D-Leu-D-Lys) -4-aminopiperidine-4-acyl) piperidin-3-yl) boronic acid

Compound 12 was prepared as described in Example 1, except that the raw material of borate was 1-N-tert-butoxycarbonylpiperidine-3-boronic acid pinacol ester.

ESI-MS (m/z) : 791.5 (M+H ⁺)

1H NMR (400 MHz, DMSO-d ₆) δ 8.85 – 8.71 (m, 1H) , 8.56 – 8.36 (m, 3H) , 8.34 – 8.25 (m, 1H) , 8.23 – 8.13 (m, 1H) , 8.03 (s, 3H) , 7.88 – 7.55 (m, 4H) , 7.37 – 7.16 (m, 10H) , 4.77 – 4.57 (m, 2H) , 4.46 – 4.16 (m, 2H) , 4.12 – 3.84 (m, 3H) , 3.51 – 3.30 (m, 1H) , 3.18 – 2.86 (m, 5H) , 2.83 – 2.56 (m, 4H) , 2.41 – 1.98 (m, 2H) , 1.94 – 1.71 (m, 3H) , 1.69 – 1.06 (m, 12H) , 0.92 – 0.84 (m, 6H) .

Biological evaluation of some polypeptide derivatives prepared in the above examples was carried out.

1. Agonistic activity and selectivity of the κ-opioid receptors

Forskolin can stimulate the release of cAMP from HEK293 cells with high expression of human κ(or μ, or δ) -opioid receptors. The κ-opioid receptor agonists can inhibit the release of cAMP from the HEK293 cells with high expression of human κ-opioid receptors stimulated by Forskolin, but do not affect the release of cAMP from the HEK293 cells with high expression of human μ (or δ) -opioid receptors stimulated by Forskolin. The efficacy of the compounds of the invention as κ-opioid receptor agonists was determined by measuring the ability of the compounds of Examples to inhibit adenylate cyclase activity.

Cell culture: The HEK293 cell line highly expressing human κ (or μ, or δ) -opioid receptor were cultured in DMEM medium containing 10% FBS.

Stimulation: the test compound was 4-fold diluted in a gradient manner to obtain 10 concentrations, and 50 nl of each was transferred to a 384-well plate, and then 10 nl Forskolin was added; the cells were digested, re-suspended, and counted; and then 10 μl of cell suspension (5×10 ⁵ cell/mL) was added, and the cells were mixed gently, and incubated at 23℃ for 60 minutes.

Detection: cAMP Assay Kit (Cisbio) was used, cAMPD2 and Anti-cAMP conjugate were added, and the resultant mixture was incubated for 1 h at room temperature. The plate was read using envision (Perkin Elmer) and EC ₅₀ was obtained by means of fitting with a four-parameter equation.

Experimental results: As shown in Table 1, the agonistic activities (EC ₅₀) of all the tested compounds are below the nM level, and they have excellent selectivity for the κ-opioid receptor.

Table 1 Agonistic activity and selectivity of the compounds on κ-opioid receptors (EC ₅₀)

2. Inhibition of cytochrome P ₄₅₀ oxidase

The human liver microsomes (0.253mg/mL protein) containing cytochrome P ₄₅₀, test compounds (0.05-50μM) , CYPs substrates (10μM p-acetaminophen, 5μM diclofenac, 30μM mephenytoin, 5μM dextromethorphan hydrobromide, 2μM midazolam) , 1.0 mM NADP were incubated at 37℃ for 10 minutes. Naphthoflavone, sulfaphenazole, N-3-benzylnivan, quinidine, and ketoconazole were used as reference inhibitors. The results are shown in Table 2. The IC ₅₀ of the test compounds on five common P ₄₅₀ enzyme subtypes are all greater than 50 μM.

Table 2 Inhibitory activity (IC ₅₀) of the compounds on cytochrome P ₄₅₀ CYP isoenzyme

3. Membrane permeability of the compounds

The Caco-2 cell line is a human colon adenocarcinoma cell line that differentiates in culture and is used to model the epithelial lining of the human small intestine. Compounds of the present invention were tested in a membrane permeability assay using Caco-2 cell membrane layer in a standard assay. The apparent permeability coefficient (Papp) can be determined in the apical-to-basolateral (A-B) direction across cell monolayers cultured on 96-well polycarbonate membrane filters. The compound was maintained at pH 7.4 on the acceptor side at a concentration of 5 μM, and the test plate was gently shaken and incubated at 37℃ for 120 minutes. Samples were taken at time zero from the donor side and at the end of the incubation period from both the donor and acceptor sides. Samples were analyzed by HPLC-MS/MS. The Papp value (expressed as 10 ⁶ cm/sec) was then calculated based on the appearance rate of compound on the recipient side. Papp can be calculated by the following equation:

Papp = (VA× [drug] _acceptor) / (Area×Time× [drug] _{initial, donor})wherein Papp is the apparent permeability; VA is the volume of the acceptor side, Area is the surface area of the membrane, [drug] _{initial, donor} is the concentration on the donor side at time zero, [drug] _acceptor is the concentration of the compounds on the recipient side at the end of the incubation period, Time is the total incubation time.

Table 3 Membrane permeability of the compounds

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A kind of synthetic peptide amide compounds, having a structure as shown in general formula (I) :

or tautomers, mesomers, racemates, enantiomers, diastereomers or mixtures thereof, isotope derivatives, solvates, or metabolites thereof, prodrugs or pharmaceutically acceptable salt or ester thereof;

wherein n is any integer from 0 to 3;

R ¹, R ² are selected from hydrogen, alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, phthaloyl, p-toluenesulfonyl, o-nitrobenzenesulfonyl, p-nitrobenzenesulfonyl, benzyloxycarbonyl, 9-fluorenylmethyloxycarbonyl, allyloxycarbonyl, trimethylsilylethyloxycarbonyl, C1-C8 alkoxycarbonyl, C1-C8 acyl, trifluoroacetyl, arylformyl, trityl, benzyl, 2, 4-dimethoxybenzyl and p-methoxybenzyl, wherein the alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, or heteroarylalkyl is optionally substituted by one or more substituents selected from alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxy, ester group, boronic acid (borate) group, acylamino, mercapto, amidino and ureido, and the heterocycloalkyl or heteroaryl contains 1 to 3 heteroatoms selected from N, O, and S;

R ³, R ⁴, R ⁵, R ^a, R ^c, R ^e, and R ^g are each independently selected from hydrogen, halogen and C1-C10 alkyl;

R ^b, R ^d, R ^f, and R ^h are each selected from the following groups:

hydrogen, halogen, C1-C10 alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxyl, ester group, boronic acid (borate) group, acylamino, mercapto, amidino and ureido, wherein the alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl or alkynyl is substituted by one or more substituents selected from alkyl, alkoxy, haloalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkenyl, alkynyl, hydroxyl, amino, nitro, cyano, carboxy, ester group, sulfonyl, sulfinyl, phosphoryl, phosphinyl, sulfonate (sulfinate) , phosphate (phosphite) , boronic acid (borate) group, acylamino, mercapto, amidino and ureido, and the heterocycloalkyl or heteroaryl contains 1 to 3 heteroatoms selected from N, O, and S;

is an optionally substituted 3- to 8-membered heterocyclic group, wherein Y is selected from C, N, O and S; the heterocyclic group is selected from aromatic heterocyclic ring, non-aromatic heterocyclic ring, and bridged-ring, fused-ring and spiro-ring comprising the heterocyclic ring; wherein the aromatic heterocyclic ring, non-aromatic heterocyclic ring, bridged-ring, fused-ring or spiro-ring is optionally substituted by one or more substituents selected from hydroxyl, amino, C1-C10 alkyl, alkoxy, alkenyl, alkynyl, ester group, acylamino, halogen, nitro, cyano, and mercapto,

W is selected from C1-C10 alkylamino, cycloalkylamino, aromatic and non-aromatic heterocyclylamino, arylamino, arylalkylamino, aromatic and non-aromatic heterocyclylalkylamino, 3-8-membered aromatic heterocyclic ring and non-aromatic heterocyclic ring, and bridged-ring, fused-ring and spiro-ring containing the heterocyclic ring; the aromatic heterocyclic ring or non-aromatic heterocyclic ring, bridged-ring, fused-ring or spiro-ring contains 1 to 3 heteroatoms optionally selected from N, O, and S, and contain at least 1 N atom;

wherein 1 N atom in W is directly connected to the carbonyl on the left side of the structural formula to form an amide bond;

B (OR ⁶) ₂ is directly connected to the atom on the heterocyclic ring in W, or is connected to the atom on the substituent of the heterocyclic ring;

B (OR ⁶) ₂ is selected from any of the following structures, and a part of atoms in two R ⁶ groups are connected to form a cyclic substituent:
The synthetic peptide amide compounds according to claim 1, wherein in general formula (I) , R ¹ together with one or more atoms of R ², R ^a, and R ^b forms a ring having any of the following structures:
The synthetic peptide amide compounds according to claim 1, wherein in general formula (I) , R ^b, R ^d, R ^f, and R ^h are independently selected from C1-C10 alkyl and the following structures:

the C1-C10 alkyl or the above-mentioned structure is optionally substituted by one or more substituents selected from halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, amino, hydroxyl, cyano, nitro, acylamino, ester group, sulfonyl, sulfinyl, phosphoryl, phosphinyl, sulfonate (sulfinate) , phosphate (phosphite) , boronic acid (borate) group, 3-10 membered heterocyclyl, C1-C10 cycloalkyl, C6-C14 aryl, and C5-C15 heteroaryl;

A and E are independently selected from NH, O, S and Se; and

n ₁, n ₂, n ₃, n ₄, and n ₅ are selected from any integer from 0 to 8.
The synthetic peptide amide compounds according to claim 1, wherein the synthetic peptide amide compounds have a structure as shown in general formula (II) :

or tautomers, mesomers, racemates, enantiomers, diastereomers or mixtures thereof, isotope derivatives, solvates, or metabolites thereof, prodrugs or pharmaceutically acceptable salt or ester thereof;

wherein W is -W ₁-W ₂-; W ₁ is a 3-8-membered aromatic or non-aromatic nitrogen-containing heterocyclic group, or bridged-ring, fused-ring or spiro-ring containing the nitrogen-containing heterocyclic group, and N is connected to carbonyl; W ₂ is selected from C1-C10 alkyl, C1-C10 alkylamino, vinyl and ethynyl;

or W is -NH-W ₃-, and NH is connected to carbonyl; W ₃ is selected from C1-C10 alkyl, C3-C10 cycloalkyl, C6-C10 aryl, 3-8 membered aromatic and non-aromatic heterocyclic group, arylalkyl, and heterocyclylalkyl.
The synthetic peptide amide compounds according to any one of claims 1-4, wherein
is selected from any of the following structures:

wherein m, m ₁, m ₂, m ₃ and m ₄ are any integers from 0 to 6.
The synthetic peptide amide compounds according to claim 1, wherein the synthetic peptide amide compounds have any of the following structures:

or tautomers, mesomers, racemates, enantiomers, diastereomers or mixtures thereof, isotope derivatives, solvates, or metabolites thereof, prodrugs or pharmaceutically acceptable salt or ester thereof.
A pharmaceutical composition comprising the synthetic peptide amide compounds according to any one of claims 1-6, and a pharmaceutically acceptable carrier, excipient, diluent, adjuvant, medium or a combination thereof.
Use of the synthetic peptide amide compounds according to any one of claims 1-6 or the pharmaceutical composition according to claim 7 in the field of medicine.
The use according to claim 8, wherein the use is for preventing or treating diseases associated with κ-opioid receptor in mammals.
The use according to claim 9, wherein the diseases associated with κ-opioid receptor are selected from pain, inflammation, pruritus, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma; wherein the pain is selected from neuropathic pain, somatic pain, visceral pain, skin pain, arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, dyspepsia, post-surgical pain, pain after medical treatment, headache, toothache, cervical pain, eye pain, otitis pain, chest pain, abdominal pain, low back and leg pain, gout, rheumatism, rheumatoid, cancer pain and pain associated with gastrointestinal dysfunction.
A method for preventing or treating diseases associated with κ-opioid receptor in mammals, comprising administering a therapeutically effective amount of the synthetic peptide amide compounds according to any one of claims 1-6 or the pharmaceutical composition according to claim 7 to mammals in need.