Compounds constituting C20-modified salinomycin derivatives, methods for obtaining them, compositions containing them, uses of the above compounds, and methods for obtaining intermediate products

Abstract

The present invention relates to a compound represented by general formula (2): [C117] The present invention relates to compounds comprising C20-N-acyl derivatives of salinomycin having the general formula (2) and salts thereof, the compounds having the general formula (2) and salts thereof, for use as pharmaceutical agents, particularly anticancer agents.

Description

Technical Field

[0001] The present invention relates to individually modified salinomycin derivatives modified at the C-20 position, methods for obtaining them, compositions containing them, and their use as medicaments, in particular as anticancer agents. The present invention also relates to a method for obtaining an intermediate product in a method for obtaining a salinomycin derivative modified at the C-20 position.

Background Art

[0002] One of the most widely used methods for identifying new cancer drugs is the chemical modification of natural compounds that have demonstrated high biological activity. Salinomycin is a natural polyether ionophore antibiotic isolated from Streptomyces albus and commonly used in veterinary medicine, having the formula (1):

Chemical formula

[0003] Salinomycin is known for its high antibacterial activity, but its anticancer activity is also known. In in vitro and in vivo tests, salinomycin has shown effectiveness against a variety of cancer cells, including drug-resistant cells and cancer stem cells. The biological mechanism of action of salinomycin relates to the ability of this compound to selectively complex with metal cations, mainly sodium and potassium cations, and then transport them across biological membranes. This results in an imbalance of cations in the cell, changes the intracellular pH, and ultimately leads to cell death. The high anticancer activity of salinomycin also relates to the effects of the above compound on various molecular targets and signaling pathways, including AMPK, MAPK, VEGF, or Wnt / β-catenin. Salinomycin has been successfully used in a small patient group with advanced head, neck, breast, and ovarian cancers. Salinomycin therapy has resulted in the suppression of cancer progression without acute side effects, thus demonstrating the high therapeutic potential of this compound.

[0004] European Patent Application Publication No. 3191493 and scientific publication [Mai et al., Nature Chemistry, 9, 2017, 1025-1033] disclose amine derivatives obtained at the C-20 position of salinomycin. In in vitro studies, some compounds exhibited higher anticancer activity and selectivity against CD24 cancer stem cells and the ability to suppress tumor spheroid formation compared to the original salinomycin. The use of the C-20 amine derivatives of salinomycin also resulted in a decrease in tumor volume and weight in mice transplanted with human MCF-7 breast cancer. The high anticancer activity of the above derivatives is related to their ability to induce ferroptosis, i.e., programmed cell death that depends on iron cation content. The findings disclosed in European Patent Application Publication No. 3191493 and scientific publication [Mai et al., Nature Chemistry, 9, 2017, 1025-1033] only refer to in vivo studies conducted in mice. The mouse body is significantly different from the human body, which makes it impossible to simply replace the results of these studies as the actual therapeutic ability of the obtained salinomycin derivatives.

[0005] Also, in the scientific publication [Li et al., European Journal of Medicinal Chemistry, 148, 2018, 279 - 290], the authors disclosed N - amide and N - carbamate (urethane) derivatives of C20 - epi - salinomycin having the opposite absolute configuration (S absolute configuration instead of R) at the C - 20 asymmetric carbon. The in vitro anticancer activities of the above - mentioned compounds were tested against a series of cancer cell lines: 4T1 (mouse breast cancer), A549 (human lung adenocarcinoma), HL - 60 (human promyelocytic leukemia), HeLa (human cervical cancer), MCF - 7 (human breast cancer), SMMC - 7721 (human liver cancer), and SW480 (human colorectal adenocarcinoma). The data disclosed in the scientific publication [Li et al., European Journal of Medicinal Chemistry, 148, 2018, 279 - 290] demonstrate that most of the obtained C20 - epi - salinomycin derivatives exhibit high anticancer activity compared to the starting compound. Studies conducted on the normal BEAS - 2B cell line (human bronchial epithelial cells) further revealed that C20 - epi - salinomycin with the highest anticancer activity is further characterized by a high selectivity of action that can be several times higher than that exhibited by unchemically modified salinomycin. The information disclosed in the scientific publication [Li et al., European Journal of Medicinal Chemistry, 148, 2018, 279 - 290] is limited to in vitro studies only, which means that the "in vivo" effects (in vivo studies) of the above - mentioned compounds are still unknown. The ability of the obtained C20 - epi - salinomycin derivatives to overcome cancer cell drug resistance is also unknown.

Summary of the Invention

[0006] The anticancer activity of biologically active compounds containing salinomycin and its derivatives is closely correlated with the type of cell line used in the test. However, none of the salinomycin derivatives synthesized so far have found practical medical applications, which is due to, for example, insufficient detailed studies on low biological activity, low action selectivity, biological action mechanisms or pharmacokinetic and pharmacodynamic properties. Therefore, intensive efforts are being continued to obtain salinomycin derivatives with a high therapeutic index that can be applicable in oncology therapy.

[0007] Obtaining new salinomycin derivatives is accompanied by several synthetic problems that need to be solved. The intermediate products required to obtain salinomycin and its derivatives may be unstable in the reaction medium, especially in the presence of acidic and / or basic agents. Salinomycin and its derivatives are sensitive to high temperatures and may therefore undergo irreversible degradation. The presence of multiple functional groups presents further challenges regarding the selective modification of the salinomycin molecule, for example, any chemical and regioselective modification of one of the three hydroxyl groups present in its structure. Another problem is the exorbitant price of commercially available salinomycin, which significantly hinders the development of new efficient methods for the chemical modification of the compound.

[0008] Therefore, the present invention addresses the difficulties in the prior art regarding the preparation of salinomycin derivatives modified at the C-20 position while retaining the absolute configuration R of the asymmetric C-20 carbon atom (similar to the starting salinomycin). Accordingly, the subject matter of the present invention was to obtain new salinomycin derivatives modified at the C-20 position using the method described in the present invention. The above method involves obtaining intermediate products as a result of specific conversions involving selected reactions, reactants, and reagents, and reaction conditions that enable the acquisition of the above derivatives while retaining the absolute configuration R at the asymmetric carbon at the C-20 position in a relatively simple and efficient process.

[0009] A further subject of the present invention was to obtain new derivatives of salinomycin, a natural ionophore, modified at the C-20 position, in the acid form and its salts, which are usable in anti-cancer therapy. The subject of the present invention is also to provide such salinomycin derivatives modified at the C-20 carbon, which are active against cancer cells with a very advantageous selectivity.

[0010] Surprisingly, it has been found that the salinomycin derivatives described in the present invention have very good activity and selectivity against cancers selected from the group including neoplastic diseases, in particular melanoma, colon cancer, breast cancer, or mixed leukemia.

[0011] The present invention relates to the general formula (2):

Chemical formula

[0012] Preferably, these compounds have the following formula:

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0013] More preferably, the compound of the present invention has the following formula: [Chemical] [Chemical] [Chemical] [Chemical] [Chemical] [Chemical] [Chemical] has

[0014] Preferably, the compound has the following formula: [Chemical] has

[0015] Even more preferably, the compound has the following formula: [Chemical] has

[0016] The present invention also relates to a pharmaceutical composition comprising the compound defined above and at least one pharmaceutically acceptable excipient.

[0017] Another subject of the present invention is a method for obtaining an intermediate product for obtaining the compound defined above. The intermediate product is of the following formula (3):

Chemical formula

Chemical formula

Chemical formula

[0018] Another subject of the present invention is C20-aminosalinomycin having the formula (3):

Chemical formula

Chemical formula

Chemical formula

[0019] Preferably, the method for obtaining the above compound is as follows: a) In the first step, the chemoselective oxidation reaction of the C20-hydroxy group of salinomycin having the formula (1):

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chemical formula

[0020] The present invention also relates to a compound as defined above for use as a medicament. Preferably, the compound is for use as an anti-cancer agent. More preferably, the compound as defined above is useful for the treatment of conditions selected from the group including, but not limited to, leukemia such as acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma; non-small cell lung cancer including, but not limited to, lung epithelial cell carcinoma, lung adenocarcinoma, human lung squamous cell carcinoma; colorectal (colon) cancer including, but not limited to, colorectal adenocarcinoma, colon epithelial cell carcinoma; central nervous system tumors including, but not limited to, brain tumors such as glioma; melanoma including, but not limited to, malignant melanoma, epithelial melanoma, non-epithelial melanoma; ovarian cancer including, but not limited to, epithelial ovarian cancer, ovarian cystadenocarcinoma; renal cancer including, but not limited to, renal cell carcinoma; prostate cancer including, but not limited to, prostate adenocarcinoma; breast cancer including, but not limited to, breast cancer, inflammatory breast cancer, metastatic adenocarcinoma; gastric cancer; pancreatic cancer; sarcoma and endometrial cancer, and drug-resistant types thereof; cervical cancer; and bladder cancer.

[0021] More preferably, the compound is for use in the treatment of conditions selected from the group of melanoma, colorectal cancer, breast cancer, and mixed leukemia.

Embodiments for Carrying Out the Invention

[0022] Preferred embodiments of the present invention are disclosed in the following detailed description and the appended claims. Various embodiments of the present invention are defined in more detail herein. Any one or more of such defined aspects can be combined with any other one or more aspects, unless a separate description makes it clear otherwise. In particular, any feature shown as advantageous or preferred can be combined with any other one or more features shown as advantageous or preferred.

[0023] References to "embodiments" or "aspects" of the invention throughout this specification are to be understood to mean that a particular feature, structure, or characteristic described in connection with such an embodiment is included in at least one embodiment of the invention. Thus, instances of the terms "embodiment", "aspect", or "variant" in various places in this specification may or may not refer to the same embodiment. Further, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments as would be apparent to one of ordinary skill in the art in the technical field of this disclosure. Additionally, some aspects of the invention described herein may include some features that are not different from those included in other embodiments, but as would be apparent to one of ordinary skill in the art, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. Any of the claimed embodiments can be used in any combination.

[0024] Most generally, the invention is of the general formula (2):

Chemical formula

[0025] The compounds described in the present invention have the absolute configuration R at the asymmetric C-20 carbon. The absolute configuration of the asymmetric C-20 carbon of the novel derivative is the same as that of the asymmetric C-20 carbon of the starting salinomycin. Therefore, the preparation of the novel salinomycin derivatives described in the present invention realizes the retention of the configuration of the asymmetric C-20 carbon of salinomycin.

[0026] The X moiety in the compounds described in the present invention can be R, O-R, or NH-R. Preferably, X represents R. In that case, the salinomycin derivative can be referred to as an N-amide derivative. More preferably, R represents O-R. In that case, the salinomycin derivative can be referred to as an N-carbamate (urethane) derivative. Even more preferably, R can represent NH-R. In that case, the salinomycin derivative can be referred to as a urea derivative. For all types of novel salinomycin derivatives listed in the specification, the R substituent is as defined in detail below without limitation. It will be apparent to those skilled in the art that other R substituents similar to those listed below and even those listed as specific groups are also within the scope of the present invention.

[0027] In a preferred embodiment of the present invention, the R substituent in the general formula (2) defining the compound according to the present invention is a linear or branched alkyl group containing 1 to 10 carbons. Preferably, the R substituent is a linear alkyl group. More preferably, R is a branched alkyl group. Preferably, the alkyl group contains 1 to 10 carbons, more preferably 1 to 5 carbons, and even more preferably 1 to 3 carbons. Preferably, R is a methyl, ethyl, n-butyl, isopropyl, neopentyl residue.

[0028] In another preferred embodiment of the present invention, the R substituent in the general formula (2) defining the compound according to the present invention is a linear or branched alkyl group containing 1 to 10 carbons, which is substituted with 1 to 5 halogens that may be present on the same carbon or different carbons at any position of the carbon chain. "Halogen" refers to fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), particularly an atom of chlorine. Preferably, the R substituent is a linear alkyl group. More preferably, R is a branched alkyl group. Preferably, the alkyl group contains 1 to 10 carbons, more preferably 1 to 5 carbons, and even more preferably 1 to 3 carbons. Preferably, R is an alkyl monohalide. More preferably, R is an alkyl dihalide or an alkyl trihalide. Preferably, R is a chloromethyl, 3-chloropropyl, 2,2,2-trichloroethyl moiety.

[0029] In another preferred embodiment, the R substituent in the general formula (2) defining the compound according to the present invention is a linear alkyl group containing 2 to 10 carbons, which contains an ether moiety (-O-) at any position of the carbon chain. Preferably, the R substituent is a linear alkyl group. More preferably, R is a branched alkyl group. Preferably, the alkyl group contains 2 to 10 carbons, more preferably 2 to 5 carbons, and even more preferably 2 to 3 carbons. The alkyl group may contain 1 to 3 ether moieties, preferably 2, and even more preferably 1 -O- group. Preferably, R is a dimethyl ether moiety.

[0030] In a preferred variant of the invention, an R group which constitutes the alkyl group defined above and which contains both one or more halogen substituents and an ether moiety may also be present. "Halogen" denotes an atom of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), especially chlorine. Preferably, R is an alkyl containing one ether moiety and substituted with one halogen.

[0031] In another preferred embodiment, the R substituent in general formula (2) which defines the compounds according to the invention is a linear alkyl group containing from 3 to 10 carbons and containing a multiple bond, either a double bond or a triple bond, at any position of the carbon chain. Preferably, the alkyl group contains from 3 to 10 carbons, more preferably from 3 to 5 carbons, even more preferably 3 carbons. Preferably, the R group is a propargyl (prop-2-ynyl) moiety.

[0032] In another preferred embodiment of the invention, the R substituent in general formula (2) which defines the compounds according to the invention is a monocyclic, bicyclic, or tricyclic alkyl group containing from 5 to 10 carbons. Preferably, the cyclic alkyl group may be substituted by a halogen. "Halogen" denotes an atom of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), especially chlorine. Preferably, R is adamantyl. R may also be a cyclopentyl or cyclohexyl substituent.

[0033] In another preferred embodiment of the invention, the R substituent in general formula (2) which defines the compounds according to the invention is an aromatic aryl group. Preferably, R is a 6-membered aromatic ring. Preferably, R is a phenyl substituent.

[0034] In another preferred embodiment, the R substituent in general formula (2) defining the compounds described in the present invention is an aromatic aryl group substituted with 1 to 3 substituents independently selected from alkyl, alkoxy, hydroxy, nitro, and nitrile groups, or halogen. "Halogen" refers to an atom of fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), particularly chlorine. Preferably, the aryl group contains two of the aforementioned substituents. These may be two halogens. They may also be two nitro groups. More preferably, the aryl group contains an alkyl substituted with 1, 2, or 3 halogens. The above groups may be present at the ortho, meta, or para positions of the aryl group. Preferably, the R substituent is a para-chloromethylphenyl substituent.

[0035] In another preferred embodiment, the R substituent in general formula (2) defining the compounds described in the present invention is an aromatic heteroaryl group in which one or more carbons are substituted with one or more heteroatoms from the group consisting of oxygen, nitrogen, or sulfur atoms. Preferably, the heteroatom is an oxygen atom. Preferably, the heteroatom is a sulfur atom. Preferably, the heteroatom is a nitrogen atom. Preferably, the R substituent is a 1-furyl residue.

[0036] In another preferred embodiment, the R substituent in general formula (2) defining the compounds described in the present invention is an alkyl-aryl group in which the aforementioned aromatic aryl group defined above is linked to the salinomycin molecule by a carbon chain containing 1 to 5 carbons. Preferably, the carbon chain is straight or branched.

[0037] Preferably, the compounds described in the present invention may also be in the form of salts. The general formula for the salts of the salinomycin derivatives described in the present invention is general formula (2a):

Chemical formula

[0038] Preferred salts of the compounds described in the present invention are sodium, potassium, or lithium salts. In that case, Y in general formula (2a) is Na, K, Li, respectively. Preferably, Y represents Na. The scope of the present invention also includes salts having divalent metals such as magnesium, for example.

[0039] Those skilled in the art will recognize how to select and adjust the conditions for obtaining the acid derivative or its desired salt. When salinomycin and its derivatives are extracted with an aqueous solution of sulfuric(VI) acid or hydrochloric acid, the acid form is produced (Y = H). When salinomycin and its derivatives are extracted with an aqueous solution of a suitable inorganic salt, the compound in the form of a salt is obtained this time (Y = Na, K, Li). Preferably, extraction with sodium carbonate, potassium carbonate, or lithium carbonate is used to obtain the sodium, potassium, or lithium salts of the compounds described in the present invention.

[0040] The present invention also relates to a composition comprising a compound described in the present invention and at least one pharmaceutically acceptable excipient. Pharmaceutically acceptable excipients are known in the art and are exemplified in Remington: The Science and Practice of Pharmacy 1995, ed. by E.W. Martin, Mack Publishing Company, 19th Edition, Easton, Pa. Preferably, the composition comprises one compound described in the present invention and at least one pharmaceutically acceptable excipient.

[0041] The present invention also relates to a method for obtaining a novel compound described in the present invention, namely a C20-modified salinomycin derivative, by reacting C20-aminosalinomycin (3) with a compound having general formula (4), (5), (6), or (7) described in the claims. For further clarity, this method is presented in two preferred embodiments: - When the reactant is a compound having general formula (4), (5), or (6), - When the reactant is a compound having general formula (7) will be described.

[0042] Therefore, a preferred embodiment of the present invention is formula (3):

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0043] The method optionally comprises the step of converting the obtained acid form of the compound into its salt. Those skilled in the art will recognize the method of selecting the reaction conditions for converting the acid form of the salinomycin derivative into its salt.

[0044] The correct order of adding the individual reactants is essential for a successful reaction to obtain C20-N-amide and C20-N-carbamate (urethane) salinomycin derivatives having the general formula (2) (wherein X separately represents R or O-R, and R is as defined above). Since salinomycin reacts very readily with the acid chloride having the general formula (4), the chloroformate having the general formula (6), and hydrogen chloride obtained from the reaction, both the acid chloride having the general formula (4) and the chloroformate having the general formula (6) are first mixed with 4-dimethylaminopyridine (DMAP) and a suitable aliphatic amine, and finally C20-aminosalinomycin having the formula (3) is added to the mixture according to the procedure described in detail below.

[0045] When using the acid chloride having the general formula (4) or the chloroformate having the general formula (6), the reaction is carried out in a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or an aprotic polar solvent, such as a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide, in the presence of 4-dimethylaminopyridine (DMAP) and an aliphatic amine which act as reaction activators. More preferably, the reaction is carried out under anhydrous conditions. The aliphatic amine used is triethylamine, tripropylamine, tributylamine, diisopropylamine, triisopropylamine, triisobutylamine, N,N-diisopropylethylamine, most preferably triethylamine. The aliphatic amine forms a complex with the by-product obtained from the reaction, i.e., hydrogen chloride. The binding of hydrogen chloride by the aliphatic amine prevents unwanted side reactions and prevents the irreversible decomposition of the compound having the formula (3).

[0046] In the first stage of the reaction, an aliphatic amine, preferably triethylamine, followed by an acid chloride having the general formula (4) or a chloroformate having the general formula (6), is added at 0 °C to a solution in a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran of 4-dimethylaminopyridine (DMAP), preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or a polar aprotic solvent, such as a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide. This is mixed at a reduced temperature (less than 5 °C) for 30 minutes, followed by the addition of C20-aminosalinomycin having the formula (3) previously dissolved in a minimal amount of a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or a minimal amount of an aprotic polar solvent, such as a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide. Considering the risk of side reactions and the possibility of irreversible decomposition of the compound having the formula (3), the reaction should be carried out at a reduced temperature (less than 5 °C) for a further 30 minutes. Then, the cooling of the reaction system is stopped, the reaction mixture is allowed to warm up naturally to room temperature, and mixing is continued until the reaction is complete, preferably while monitoring by thin layer chromatography TLC.

[0047] Next, the reaction mixture is washed with an aqueous solution of sodium carbonate (0.1 M). The organic layer is evaporated under reduced pressure, and the residue is purified by column chromatography using a column filled with silica and a mixture of organic solvents, preferably a mixture of ethyl acetate:n-hexane with a rising gradient of ethyl acetate concentration from 0% to 100%, preferably using a CombiFlash® chromatograph equipped with an ELS detector. The combined fractions containing C20-N-amide or C20-N-carbamate (urethane) as the reaction product are evaporated to dryness under reduced pressure, and the residue is dissolved in a non-polar chloroaliphatic solvent, preferably methylene chloride or chloroform, and subsequently extracted with an aqueous solution of a suitable salt (0.1 M) or an aqueous solution of sulfuric acid or hydrochloric acid (pH = 1.0), and finally with water. The combined organic layers are evaporated to dryness under reduced pressure and then repeatedly evaporated with n-pentane.

[0048] When using carboxylic acids having the general formula (5), for the success of the reaction it is essential to pre - appropriately activate them using suitable coupling agents / activators according to the procedures described in detail below. The reaction is carried out in a non - polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or an aprotic polar solvent, such as a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N - dimethylformamide. More preferably, the reaction is carried out under anhydrous conditions and in the presence of a coupling agent. The coupling agents used are N,N'-dicyclohexylcarbodiimide (DCC), N,N'-diisopropylcarbodiimide (DIC), 1,1'-carbonyldiimidazole (CDI), 1 - ethyl - 3-(3'-dimethylaminopropyl)carbodiimide hydrochloride (EDC), 2-(7 - azabenzotriazol - 1 - yl)-1,1,3,3 - tetramethyluronium hexafluorophosphate (HATU), and when N,N'-dicyclohexylcarbodiimide (DCC) is used, it is also preferred to use p - toluenesulfonic acid, N - hydroxysuccinimide, 3 - hydroxy - 4 - keto - 1,2,3 - benzotriazine, N - hydroxybenzotriazole (HOBt), 4 - dimethylaminopyridine (DMAP), or 4 - pyrrolidinopyridine.

[0049] In the first stage of the reaction, the coupling agent is added at room temperature to a solution of the carboxylic acid having the general formula (5) in a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or an aprotic polar solvent, for example a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide. This is mixed at room temperature for 30 minutes, and subsequently C20-aminosalinosomycin having the formula (3), which has been previously dissolved in a minimum amount of a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or a minimum amount of an aprotic polar solvent, for example a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide, is added. Mixing is continued at room temperature until the reaction is complete, and the completion of the reaction of the reactants is preferably monitored by thin layer TLC chromatography.

[0050] The reaction mixture is then evaporated under reduced pressure, and the residue is purified by column chromatography using a column filled with silica and a mixture of organic solvents, preferably a mixture of ethyl acetate:n-hexane with a rising gradient of 0% to 100% ethyl acetate concentration, preferably using a CombiFlash® chromatograph equipped with an ELS detector. The combined fractions containing the C20-N-amide reaction product are evaporated to dryness under reduced pressure, and the residue is dissolved in a non-polar chloroaliphatic solvent, preferably methylene chloride or chloroform, and subsequently extracted with an aqueous solution of a suitable salt (0.1 M) or an aqueous solution of sulfuric acid or hydrochloric acid (pH = 1.0), and finally with water. The combined organic layers are evaporated to dryness under reduced pressure and then repeatedly evaporated with n-pentane.

[0051] In another preferred embodiment mentioned, the present invention Formula (3):

Chemical formula

Chemical formula

[0052] The method optionally comprises the step of converting the obtained compound in acid form into its salt. A person skilled in the art will recognize the method for selecting the reaction conditions for converting the salinomycin derivative in acid form into its salt.

[0053] The reaction with the isocyanate having general formula (7) is carried out at room temperature in a non-polar chloroaliphatic or aromatic solvent or tetrahydrofuran, preferably chloroform, methylene chloride, toluene, benzene, tetrahydrofuran, most preferably chloroform or methylene chloride, or an aprotic polar solvent, such as a simple nitrile, preferably acetonitrile, or a simple tertiary amide, preferably N,N-dimethylformamide. More preferably, the reaction is carried out under anhydrous conditions.

[0054] Once the reaction is complete (completion of the reaction is preferably monitored using thin layer chromatography TLC), the reaction mixture is washed with an aqueous solution of sodium bicarbonate (0.1 M). The organic layer is evaporated under reduced pressure and the residue is purified by column chromatography using a column filled with silica and a mixture of organic solvents, preferably a mixture of ethyl acetate:n-hexane with a rising gradient of ethyl acetate concentration from 0% to 100%, preferably using a CombiFlash® chromatograph equipped with an ELS detector. The combined fractions containing the C20-urea reaction product are evaporated to dryness under reduced pressure and the residue is dissolved in a non-polar chloroaliphatic solvent, preferably methylene chloride or chloroform, followed by extraction with an aqueous solution of a suitable salt (0.1 M) or an aqueous solution of sulfuric acid or hydrochloric acid (pH = 1.0), and finally with water. The combined organic layers are evaporated to dryness under reduced pressure and then evaporated repeatedly with n-pentane.

[0055] The present invention also relates to a method for obtaining an intermediate product for a method for obtaining a salinomycin derivative modified with C-20 carbon. The three-step procedure for the synthesis of the intermediate compound having formula (3) is carried out using activated manganese(IV) oxide at room temperature in a non-polar chloroaliphatic solvent, preferably methylene chloride or chloroform, starting from the chemoselective oxidation of the C20-hydroxy group of salinomycin having formula (1) [described in European Patent Application Publication No. 3191493 or Mai et al., Nature Chemistry, 9, 2017, 1025-1033], to give formula (8):

Chemical formula

[0056] The conversion of compounds having formula (8), which are widely exemplified in the prior art, to compounds having formula (3) has been enhanced and modified for the purposes of the present invention. The modified procedure for the preparation of compounds having formula (8) involves using an alcoholic solution of ammonia at a suitable concentration and increasing the activation (imine formation) time to 5 hours. In the modified procedure, it is no longer necessary to use acetic acid in the imine formation step nor to treat the reaction mixture by liquid-liquid extraction after the reaction, thereby significantly simplifying and accelerating the overall synthetic procedure.

[0057] In the first stage of reductive amination, ammonia (7.0 N in methanol) reacts with C20-oxosalinomycin having formula (8) dissolved in an alcoholic solvent, preferably methanol or ethanol, at room temperature to form an imine in situ. According to the Luche reduction, in the second stage of reductive amination, the reaction intermediate (imine) is reduced by slowly adding sodium borohydride or a sodium borohydride derivative, particularly sodium cyanoborohydride, in the presence of a cerium salt, preferably cerium(III) chloride, to obtain C20-aminosalinomycin having formula (3).

[0058] The present invention also relates to the use of the novel salinomycin derivatives described herein for use as a medicament. In a preferred embodiment, the compounds described herein are intended for use as anti-cancer agents.

[0059] The compounds according to the invention are suitable for use in a condition selected without limitation from the group including leukemia such as acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, mixed leukemia, multiple myeloma; non-small cell lung cancer including, without limitation, lung epithelial cell carcinoma, lung adenocarcinoma, human lung squamous cell carcinoma; colorectal (colon) cancer including, without limitation, colorectal adenocarcinoma, colon epithelial cell carcinoma; central nervous system tumors including, without limitation, brain tumors such as glioma; melanoma including, without limitation, malignant melanoma, epithelial melanoma, non-epithelial melanoma; ovarian cancer including, without limitation, epithelial ovarian cancer, ovarian cystadenocarcinoma; kidney cancer including, without limitation, renal cell carcinoma; prostate cancer including, without limitation, prostate adenocarcinoma; breast cancer including, without limitation, breast cancer, inflammatory breast cancer, metastatic adenocarcinoma; stomach cancer; pancreatic cancer; sarcoma and corpus cancer, and drug-resistant types thereof; cervical cancer; bladder cancer.

[0060] As used herein, the terms “cancer,” “tumor,” “neoplasm,” and “carcinoma” are used interchangeably.

[0061] Preliminary studies indicate that the compounds according to the invention have anti-cancer activity against the cell lines listed below: HL-60(TB), K-562, MOLT-4, RPMI-8226, SR, A549 / ATCC, EKVX, HOP-62, HOP-92, NCI-H226, NCI-H23, NCI-H460, NCI-H522, COLO205, HCC-2998, HCT-116, HCT-15, HT29, KM12, SW-620, SF-268, SF-295, SF-539, SNB-19, SNB-75, U251, LOX IMVI, MALME-3M, M14, MDA-MB-435, SK-MEL-2, SK-MEL-28, SK-MEL-5, UACC-257, UACC-62, IGROV1, OVCAR-3, OVCAR-4, OVCAR-5, OVCAR-8, NCI / ADR-RES, SK-OV-3, 786-0, A498, ACHN, CAKI-1, RXF393, SN12C, TK-10, UO-31, PC-3, DU-145, MCF7, MDA-MB-231 / ATCC, HS578T, BT-549, T-47D, MDA-MB-468, KATOIII, NCI-N87, SNU-16, SNU-5, AGS, SNU-1, Capan-2, ATCC HTB-80, Panc10.05, CFPAC-1, HPAF-II, SW1990, BxPC-3, AsPC-1, MES-SA, MES-SA / DX5, KLE, HEC-1-A, AN3 CA, Ca-Ski, DoTc2 4510, SiHa, C-33-A, 5637, KU-19-19, MBT-2, HCV29T, Hu1703He. For some of these cell lines, the relevant specific conditions have already been described in the list above.

[0062] Anticancer activity is - preventing cancer occurrence, - suppressing the growth of cancer cells (inhibiting proliferation), - inducing cancer cell death (apoptosis-promoting effect), - preventing or inhibiting the metastasis of cancer cells, - suppressing the phenomenon of multidrug resistance, - inhibiting the angiogenesis process, - eliminating or minimizing the effects of neoplastic diseases is understood as.

[0063] In vitro studies conducted on several cancer cell lines have confirmed the high cytotoxic activity of newly prepared compounds that greatly exceed the biological activity of unchemically modified salinomycin. The obtained salinomycin derivatives demonstrate not only high anticancer activity against cancer cells but also high selectivity of action. Furthermore, a comparison of the anticancer activity and toxicity of the newly synthesized compounds with the anticancer activity and toxicity exhibited by known salinomycin derivatives from the prior art, including C20-N-amide and C20-N-carbamate (urethane) derivatives structurally similar to C20-epi-salinomycin with an inverted absolute configuration (S absolute configuration instead of R) at the C-20 asymmetric carbon [Li et al., European Journal of Medicinal Chemistry, 148, 2018, 279-290] clearly demonstrated the superiority of the compounds that are the subject of the present invention in the context of their potential therapeutic use.

[0064] The following cancer cell lines were used in the in vitro study: - B16-F0 (mouse melanoma), - Hs294T (human melanoma), - LoVo (drug-sensitive human colon cancer), - LoVo / DX (drug-resistant human colon cancer), - MCF-7 (human breast cancer), - MV-4-11 (human mixed leukemia).

[0065] Normal mouse BALB / 3T3 fibroblasts were also used in the assay to determine the selectivity coefficient of the compounds used in the assay. These values make it possible to predict the direction of action of these compounds by answering the question of whether the salinomycin derivatives can first destroy cancer cells or attack normal somatic cells.

[0066] Table 1 summarizes the data for all cell lines (both cancer and normal) used in the in vitro study. Table 1.

Table 1

[0067] During the in vitro cytotoxicity test, the culture media and reagents summarized in Table 2 were used. Table 2.

Table 2

Table 3

Table 4

[0068] The in vitro cytotoxicity test was performed according to the procedure described below. A stock solution of the test compound at 10 mg / mL was prepared freshly for each experiment by dissolving 1 mg of the preparation in 100 μL of dimethyl sulfoxide (DMSO). The solvent for further dilution was the culture medium. The compounds were tested in the concentration ranges of 100 to 0.00001 μg / mL (for B16-F0 and Hs294T cell lines) and 100 to 0.1 μg / mL (for LoVo, LoVo / DX, MCF-7, MV-4-11, and BALB / 3T3 cell lines).

[0069] An assay of the cytotoxic effects of the tested compounds and a reference compound, namely cisplatin (a commonly used anti-cancer drug), was performed in 96-hour in vitro cultures. The MTT tetrazolium salt reduction assay [as described in Wietrzyk et al., Anti-cancer drugs, 2007, 18, 447-457] was carried out on MV-4-11 cells (human mixed leukemia) to evaluate the metabolic activity of cancer cells. On the other hand, to determine the anti-proliferative activity of all the tested compounds against B16-F0 (mouse melanoma), Hs294T (human melanoma), LoVo (drug-sensitive human colon cancer), LoVo / DX (drug-resistant human colon cancer), MCF-7 (human breast cancer), and BALB / 3T3 (normal mouse fibroblast) cell lines, the SRB colorimetric assay was used [as described in Skehan et al., Journal of the National Cancer Institute, 1990, 82, 1107-1112], and the inhibition of target cell proliferation was measured based on the amount of protein in the measured cells. In each experiment, samples containing the test compound at the specified concentration were added in triplicate to 96-well plates. The experiment was repeated at least 3 times. The in vitro cytotoxicity test was carried out according to the following procedure: (a) Cells (derived from in vitro cultures) were seeded into the wells of the plate at a density of 0.20×10 4 cells (Hs294T strain), 0.25×10 4 cells (B16-F0 strain), 0.75×10 4 cells (MCF-7 strain), or 1.00×10 4 cells (LoVo, LoVo / DX, MV-4-11, and BALB / 3T3 strains) in 100 μL of culture medium, and then incubated at 37 °C in a humid atmosphere saturated with 5% carbon dioxide (CO2) (85-95% humidity), (b) After 24 hours, an additional 100 μL of medium (cell growth control) or medium containing the test compound at the specified concentration was added to the wells, (c) The plates were incubated for an additional 72 hours in an incubator (37 °C, humid atmosphere saturated with 5% CO2 (85-95% humidity)), (d) After 72 hours of incubation of the cells with the test compound, an MTT or SRB assay was performed. (e) In each experiment, samples containing the test compound at the determined concentrations were added in triplicate, and the experiment was repeated 3 - 5 times.

[0070] MTT reading: 20 μL of MTT solution was added to each well of a 96 - well plate. After 4 hours of incubation at 37°C, 80 μL of lysis buffer was added to each well. After an additional 24 - hour incubation at 37°C, the optical density of each sample was read at 570 nm using a Synergy H4 (general purpose) plate reader (BioTek Instruments, USA).

[0071] SRB reading: 50 μL of cold 50% trichloroacetic acid was added to each well of a 96 - well plate. After 60 minutes of incubation at room temperature, the plate was washed 4 times with water and then dried on a paper towel. Then, 50 μL of a 0.1% solution of sulforhodamine B (SRB) in 1% acetic acid was added to each well to stain the cellular proteins precipitated in the wells. After 30 minutes of incubation with SRB at room temperature, the plate was washed 4 times with 1% acetic acid and dried again on a paper towel. In the next step, 150 μL of 10 mM TRIS buffer was added to each well to dissolve the dye bound to the cellular proteins. The optical density of each sample was read at 540 nm using a Synergy H4 (general purpose) plate reader (BioTek Instruments, USA).

[0072] The inhibition of proliferation was calculated as a percentage for each test compound at a given concentration based on the measurement of the absorbance of individual wells using the following formula:

Equation

[0073] When calculating the mean absorbance value of a set of wells (untreated cells, cells treated with a specified compound at a specified concentration, control with medium alone), outliers were rejected using a coefficient of variation CV of 10%. Using the percentage of inhibition of growth data, the IC 50 value, i.e., the concentration of the test compound required to inhibit cell growth by 50% was determined [as in Nevozhay, PLoS One, 2014, 9, e106186]. Then, the IC 50 mean value was calculated together with the standard deviation value based on an additional 3 - 5 replicates of the test.

[0074] For comparison purposes, a similar study was conducted using a commonly used anti - cancer drug, i.e., cisplatin. The results of the in vitro cytotoxic activity of the test compounds are shown as IC 50 values in micromolar concentration (μM) units and summarized in Table 3. All of the newly obtained salinomycin derivatives have very high anti - cancer activity and, in most cases, significantly exceed the anti - cancer activity of unmodified salinomycin having formula (1), C20 - aminosalinomycin having formula (3), and the reference oncology drug cisplatin. Furthermore, unlike salinomycin, most of the newly synthesized derivatives of this ionophore were identified as anti - cancer agents that can effectively overcome the drug resistance of the cancer cells under study, having a RI drug resistance index value of less than 1.0. All of the newly obtained salinomycin derivatives are characterized by a high selectivity coefficient SI greater than 3.0 for cancer cells, and some of them were identified as very highly selective compounds (SI>100.0). This clearly shows that the effect of the newly synthesized salinomycin derivatives on cancer cells is far superior to their toxic effect on normal somatic cells. Table 3. Examples of the use of the compounds described in the present invention

Table 5

Number

Number

[0075] Table 3 clearly shows that the compounds described in the present invention have anti - cancer activity against cancer cells derived from various tissues and organs. Furthermore, the obtained derivatives have an anti - proliferative effect several times more potent (for example, derivatives having formulas (10), (15), (17)) or even dozens of times more potent (for example, compounds having formulas (21), (22), (25)) compared to the parent compound. The results of the activity tests performed on drug - sensitive and drug - resistant human colon cancer cells indicate that the compounds described in the present invention can overcome the drug resistance of cancer cells. Furthermore, the compounds described in the present invention are characterized by excellent action selectivity demonstrating their broad therapeutic ability. Those skilled in the art will recognize a method for selecting a specific derivative for treating an appropriate type of cancer. As an example, it will be pointed out that, for example, the derivative having formula (21) has a favorable effect on melanoma cells, and the compound having formula (25) has a favorable effect on mixed - lineage leukemia cells.

[0076] The compounds described in the present invention and the methods for preparing them are illustrated in the following examples. The above examples are not intended to limit the scope of protection, but merely present selected representative examples of embodiments of the present invention. It is considered within the knowledge of those skilled in the art to select reactants and adjust reaction conditions to obtain other derivatives within the scope of protection defined in the claims.

[0077] (Example 1) Preparation of C20-dehydroxy-C20-aminosalinomycin N-acetamide having formula (9): [Chemical formula] Triethylamine (8 mg, 1.2 equivalents) and acetyl chloride (7 mg, 1.2 equivalents) were added to a solution of 4-dimethylaminopyridine (10 mg, 1.2 equivalents) in anhydrous methylene chloride (7 mL) cooled to 0 °C, and this was stirred at a reduced temperature (less than 5 °C) for 30 minutes. Then, C20-aminosalinomycin (50 mg, 1.0 equivalent) previously dissolved in the minimum amount of anhydrous methylene chloride was added to the reaction mixture, and the mixture was stirred at a reduced temperature (less than 5 °C) for an additional 30 minutes. Then, this was allowed to warm naturally to room temperature, mixing was continued until the reaction was complete, and the completion of the reaction was monitored by thin-layer chromatography TLC.

[0078] After the reaction was completed, the reaction mixture was washed with an aqueous solution of sodium carbonate (0.1 M). The organic layer was evaporated to dryness under reduced pressure, and the residue was purified using a CombiFlash® chromatograph equipped with an ELS detector with a silica-packed column and a solvent mixture of ethyl acetate:n-hexane with a rising gradient of ethyl acetate concentration from 0% to 100%. The combined fractions containing C20-dehydroxy-C20-aminosalinomycin N-acetamide having formula (9) were evaporated to dryness under reduced pressure, the residue was dissolved in methylene chloride, and then extracted with an aqueous solution of sulfuric acid (pH = 1.0) and finally with water. The combined organic layers were evaporated to dryness again under reduced pressure and then repeatedly evaporated with n-pentane. C20-dehydroxy-C20-aminosalinomycin N-acetamide having formula (9) was obtained as a white amorphous solid in a yield of 72%. Yield: 38 mg, 72%. Isolated as a white amorphous solid; purity >95% by single spot on NMR and TLC. Rf: 0.54 (100% ethyl acetate). Green spot in phosphomolybdic acid (PMA). 13 C NMR (101 MHz, CDCl3) δ 215.4, 177.7, 170.2, 129.3, 122.9, 105.4, 99.4, 88.4, 77.3, 77.2, 75.5, 74.9, 73.8, 71.7, 71.0, 68.4, 56.1, 49.7, 48.9, 48.6, 41.0, 38.5, 36.8, 36.3, 32.6, 30.5, 29.0, 28.0, 26.2, 26.0, 23.1, 22.6, 22.0, 20.0, 17.9, 16.4, 15.8, 14.7, 13.2, 12.9, 12.0, 11.2, 6.9, 6.3 ppm. 11H NMR (403 MHz, CDCl3) δ ca. 13.00 (s, very br, 1H), 6.93 (d, J = 8.0 Hz, 1H), 6.03 (dd, J = 10.7, 2.6 Hz, 1H), 5.78 (dd, J = 10.6, 2.0 Hz, 1H), 4.41 (dt, J = 8.0, 2.3 Hz, 1H), 4.08 (dd, J = 10.1, 1.4 Hz, 1H), 3.92 (dd, J = 10.8, 5.4 Hz, 1H), 3.84 (dd, J = 8.9, 5.3 Hz, 1H), 3.80 (d, J = 10.3 Hz, 1H), 3.75 (dd, J = 14.0, 7.0 Hz, 1H), 3.57 (dd, J = 9.9, 1.8 Hz, 1H), 2.83 (td, J = 10.8, 3.8 Hz, 1H), 2.67 (dq, J = 9.8, 7.1 Hz, 1H), 2.52 (dd, J = 11.1, 2.1 Hz, 1H), 2.10 - 0.50 (m, 56H), 1.91 (s, J = 7.4 Hz, 3H) ppm. ESI-MS (m / z): C 44 H 73 NNaO 11 + Calculated [M + Na] for + 814.5; found 814.

[0079] (Example 2) Preparation of C20-dehydroxy-C20-aminosalinomycin N-isobutylamide having the formula (10): [Chemical formula] The reaction was carried out in the same manner as in Example 1 except that isobutyryl chloride (9 mg, 1.2 equiv) was added to the reaction mixture instead of acetyl chloride (1.2 equiv). C20-dehydroxy-C20-aminosalinomycin N-isobutylamide having the formula (10) was obtained as a white amorphous solid in 29% yield. Yield: 16 mg, 29%. Isolated as a white amorphous solid; purity > 95% by single spot on NMR and TLC. Rf: 0.55 (ethyl acetate / n-hexane 50%). Green spot in phosphomolybdic acid (PMA). 1313C NMR (101 MHz, CD2Cl2) δ 215.8, 177.7, 177.4, 130.2, 123.3, 106.0, 100.0, 89.0, 77.8, 76.1, 75.2, 73.8, 72.1, 71.2, 69.0, 56.3, 49.9, 49.2, 48.8, 41.5, 39.0, 37.2, 36.6, 35.7, 33.2, 30.9, 30.9, 29.2, 28.5, 26.6, 26.1, 23.1, 22.5, 20.4, 20.0, 19.6, 18.0, 16.7, 15.9, 15.0, 13.4, 13.2, 12.1, 11.3, 7.1, 6.5 ppm. 1 1H NMR (403 MHz, CD2Cl2) δ ca. 13.00 (s, very br, 1H), 6.78 (d, J = 7.9 Hz, 1H), 6.07 (dd, J = 10.7, 2.6 Hz, 1H), 5.76 (dd, J = 10.6, 2.1 Hz, 1H), 4.39 (dt, J = 7.9, 2.3 Hz, 1H), 4.07 (dd, J = 10.1, 1.4 Hz, 1H), 3.95 - 3.81 (m, 3H), 3.76 (dd, J = 13.9, 6.9 Hz, 1H), 3.58 (dd, J = 10.0, 2.0 Hz, 1H), 2.89 (td, J = 10.7, 4.0 Hz, 1H), 2.73 (dq, J = 10.0, 7.1 Hz, 1H), 2.61 (dd, J = 10.9, 1.9 Hz, 1H), 2.30 (dt, J = 13.6, 6.8 Hz, 1H), 2.21 - 0.55 (m, 62H) ppm. ESI-MS (m / z): C 46 H 77 NNaO 11 + Calculated [M + Na] for + 842.5; found 842.

[0080] (Example 3) Preparation of C20 - dehydroxy - C20 - aminosalinosomycin N - chloroacetamide having the formula (11): [Chemical formula] The procedure was carried out in the same manner as in Example 1, except that chloroacetyl chloride (9 mg, 1.2 eq) was added to the reaction mixture instead of acetyl chloride (1.2 eq). C20-dehydroxy-C20-aminosalinomycin N-chloroacetamide having the formula (11) was obtained as a white amorphous solid in 30% yield. Yield: 17 mg, 30%. Isolated as a white amorphous solid; purity >95% by a single spot on NMR and TLC. Rf: 0.71 (ethyl acetate / n-hexane 50%). Green spot in phosphomolybdic acid (PMA). 13 C NMR (101 MHz, CD2Cl2) δ 215.6, 177.8, 167.0, 129.0, 124.6, 105.9, 99.9, 88.9, 77.7, 76.4, 75.1, 73.5, 72.2, 71.3, 69.0, 56.1, 49.71, 49.69, 48.8, 43.2, 41.2, 38.9, 37.3, 36.5, 33.1, 31.4, 30.9, 29.3, 28.6, 26.6, 25.4, 23.0, 22.2, 20.4, 17.9, 16.7, 15.8, 14.9, 13.3, 13.2, 12.1, 11.4, 7.2, 6.5 ppm. 1 H NMR (403 MHz, CD2Cl2) δ ca. 13.00 (s, very br, 1H), 7.23 (d, J = 8.5 Hz, 1H), 6.14 (dd, J = 10.6, 2.5 Hz, 1H), 5.79 (dd, J = 10.6, 2.4 Hz, 1H), 4.50 (dt, J = 8.6, 2.4 Hz, 1H), 4.07 (dd, J = 10.1, 1.3 Hz, 1H), 4.00 (s, J = 13.8 Hz, 2H), 3.92 (dd, J = 10.8, 5.3 Hz, 1H), 3.79 (ddd, J = 14.0, 8.4, 3.0 Hz, 3H), 3.58 (dd, J = 9.9, 1.9 Hz, 1H), 2.89 (td, J = 10.7, 4.1 Hz, 1H), 2.73 (ddd, J = 14.3, 10.0, 7.1 Hz, 1H), 2.60 (dd, J = 10.8, 1.7 Hz, 1H), 2.19 - 0.55 (m, 56H) ppm. ESI-MS (m / z): C 44 H 72 ClNNaO 11+ [M+Na] calculated for + 848.5; measured value 848.

[0081] (Example 4) Preparation of C20-dehydroxy-C20-aminosalinomycin N-4-chlorobutylamide having formula (12):

Chemical formula

[0082] (Example 5) Preparation of C20 - dehydroxy - C20 - aminosalinomycin N - methoxyacetamide having formula (13): [Chemical formula] The reaction was carried out in the same manner as in Example 1, except that methoxyacetyl chloride (9 mg, 1.2 equiv) was added to the reaction mixture instead of acetyl chloride (1.2 equiv). C20 - dehydroxy - C20 - aminosalinomycin N - methoxyacetamide having formula (13) was obtained as a white amorphous solid in 44% yield. Yield: 24 mg, 44%. Isolated as a white amorphous solid; purity > 95% by single spot in NMR and TLC. Rf: 0.63 (100% ethyl acetate). Green spot in phosphomolybdic acid (PMA). 1313C NMR (101 MHz, CDCl3) δ 215.5, 177.6, 169.8, 129.1, 123.2, 105.2, 99.5, 88.8, 77.2, 75.5, 74.8, 72.8, 72.3, 71.7, 71.0, 68.4, 58.9, 56.1, 49.8, 48.9, 48.2, 41.2, 38.7, 36.42, 36.38, 32.7, 30.6, 30.3, 29.2, 28.0, 26.2, 25.8, 22.7, 22.0, 19.9, 17.9, 16.5, 15.7, 14.3, 13.3, 12.9, 11.8, 11.0, 6.8, 6.4 ppm. 1 1H NMR (403 MHz, CDCl3) δ ca. 13.00 (s, very br, 1H), 7.23 (d, J = 8.9 Hz, 1H), 6.14 (dd, J = 10.8, 2.9 Hz, 1H), 5.79 (dd, J = 10.7, 1.7 Hz, 1H), 4.62 (ddd, J = 8.9, 2.7, 1.9 Hz, 1H), 4.15 (dd, J = 10.1, 1.4 Hz, 1H), 4.02 - 3.94 (m, 2H), 3.93 - 3.78 (m, 4H), 3.63 (dd, J = 10.0, 1.9 Hz, 1H), 3.36 (s, J = 9.3 Hz, 3H), 2.89 (td, J = 10.9, 3.9 Hz, 1H), 2.74 (ddd, J = 14.2, 10.0, 7.0 Hz, 1H), 2.61 (dd, J = 10.9, 2.2 Hz, 1H), 2.22 - 0.60 (m, 56H) ppm. ESI-MS (m / z): C 45 H 75 NNaO 12 + Calculated [M + Na] for + 844.5; found 844.

[0083] (Example 6) Preparation of C20-dehydroxy-C20-aminosalinomycin N-1-adamantylcarboxamide having formula (14):

Chemical formula

[0084] (Example 7) Preparation of C20 - dehydroxy - C20 - aminosalinosomycin N - benzamide having formula (15): [Chemical formula] The procedure was carried out in the same manner as in Example 1, except that benzoyl chloride (12 mg, 1.2 equivalents) was added to the reaction mixture instead of acetyl chloride (1.2 equivalents). C20 - dehydroxy - C20 - aminosalinosomycin N - benzamide having formula (15) was obtained as a pale yellow amorphous solid in a 91% yield. Yield: 52 mg, 91%. Isolated as a pale yellow amorphous solid; purity > 95% by single spot in NMR and TLC. Rf: 0.68 (ethyl acetate / n - hexane 50%). Green spot in phosphomolybdic acid (PMA), active under UV. 13 13C NMR (101 MHz, CD2Cl2) δ 215.7, 177.6, 168.6, 136.0, 131.5, 129.8, 128.7, 127.5, 123.4, 105.9, 99.9, 89.3, 76.9, 76.3, 75.0, 73.4, 72.3, 71.1, 69.2, 56.3, 49.72, 49.66, 48.9, 41.6, 39.0, 37.2, 36.5, 33.2, 30.9, 30.7, 29.5, 28.6, 26.7, 26.1, 23.1, 22.6, 20.5, 18.0, 16.6, 15.9, 14.8, 13.4, 13.3, 12.0, 11.4, 7.2, 6.5 ppm. 11H NMR (403 MHz, CD2Cl2) δ ~13.00 (s, very br, 1H), 7.75 - 7.67 (m, 2H), 7.50 - 7.44 (m, 1H), 7.43 - 7.36 (m, 2H), 7.19 (d, J = 8.4 Hz, 1H), 6.14 (dd, J = 10.7, 2.9 Hz, 1H), 5.88 (dd, J = 10.7, 1.8 Hz, 1H), 4.68 (ddd, J = 8.4, 2.7, 1.9 Hz, 1H), 4.10 (dd, J = 10.1, 1.4 Hz, 1H), 3.97 - 3.87 (m, 2H), 3.85 - 3.79 (m, 1H), 3.59 (dd, J = 10.0, 2.1 Hz, 1H), 3.28 (dd, J = 13.6, 6.7 Hz, 1H), 2.88 (td, J = 10.6, 4.0 Hz, 1H), 2.76 (dq, J = 10.0, 7.1 Hz, 1H), 2.62 (dd, J = 10.8, 2.0 Hz, 1H), 2.24 - 0.58 (m, 56H) ppm. ESI-MS (m / z): C 49 H 75 NNaO 11 + Calculated [M + Na] for + 876.5; found 876.

[0085] (Example 8) Preparation of C20-dehydroxy-C20-aminosalinomycin N-(4-chloromethyl)benzamide having formula (16):

Chemical Structure

[0086] (Example 9) Preparation of C20 - dehydroxy - C20 - aminosalinosomycin N - 2 - fluoroamide having formula (17):

Chem.

[0087] (Example 10) Preparation of C20-dehydroxy-C20-aminosalinomycin N-methylcarbamate having formula (18): [Chemical formula] The procedure was carried out in the same manner as in Example 1, except that methyl chloroformate (8 mg, 1.2 equiv) was added to the reaction mixture instead of acetyl chloride (1.2 equiv). C20-dehydroxy-C20-aminosalinomycin N-methylcarbamate having formula (18) was obtained as a white amorphous solid in 16% yield. Yield: 9 mg, 16%. Isolated as a white amorphous solid; purity > 95% by single spot in NMR and TLC. Rf: 0.35 (ethyl acetate / n-hexane 50%). Green spot in phosphomolybdic acid (PMA). 13 13C NMR (101 MHz, CD2Cl2) δ 214.9, 177.2, 157.4, 130.1, 122.6, 105.8, 99.7, 89.6, 77.4, 76.4, 75.1, 74.4, 72.1, 71.2, 69.2, 56.5, 52.0, 50.7, 49.7, 48.4, 41.5, 38.9, 37.2, 36.5, 33.1, 31.0, 30.7, 29.4, 28.5, 26.7, 26.4, 23.1, 22.6, 20.3, 17.9, 16.8, 15.9, 14.4, 13.4, 13.3, 11.9, 11.3, 7.1, 6.5 ppm. 1 1H NMR (403 MHz, CD2Cl2) δ ca. 13.00 (s, very br, 1H), 6.39 (d, J = 6.9 Hz, 1H), 6.04 (dd, J = 10.8, 2.7 Hz, 1H), 5.83 (dd, J = 10.7, 1.6 Hz, 1H), 4.12 - 4.04 (m, 2H), 3.99 - 3.85 (m, 3H), 3.81 (dd, J = 13.7, 6.8 Hz, 1H), 3.66 - 3.53 (m, 4H), 2.91 (td, J = 10.5, 4.2 Hz, 1H), 2.75 (ddd, J = 14.2, 9.9, 7.1 Hz, 1H), 2.58 (dd, J = 10.6, 1.4 Hz, 1H), 2.25 - 2.12 (m, 2H), 2.04 - 0.57 (m, 54H) ppm. ESI-MS (m / z): C 44 H 73 NNaO 12 + Calculated [M + Na] for + 830.5; found 830.

[0088] (Example 11) Preparation of C20 - dehydroxy - C20 - aminosalinosomycin N - ethylcarbamate having formula (19):

Chem.

[0089] (Example 12) Preparation of C20 - dehydroxy - C20 - aminosalinosomycin N - neopentylcarbamate having formula (20):

Chemical formula

[0090] (Example 13) Preparation of C20-dehydroxy-C20-aminosalinosomycin N-2,2,2-trichloroethylcarbamate having the formula (21): [Chemical formula] The reaction was carried out in the same manner as in Example 1, except that chloroformic acid 2,2,2-trichloroethyl (18 mg, 1.2 eq) was added to the reaction mixture instead of acetyl chloride (1.2 eq). C20-dehydroxy-C20-aminosalinosomycin N-2,2,2-trichloroethylcarbamate having the formula (21) was obtained as a white amorphous solid in 41% yield. Yield: 32 mg, 41%. Isolated as a white amorphous solid; purity >95% by single spot in NMR and TLC. Rf: 0.50 (ethyl acetate / n-hexane 33%). Green spot in phosphomolybdic acid (PMA). 1313C NMR (101 MHz, CD2Cl2) δ 216.6, 178.0, 155.2, 129.6, 123.2, 105.5, 100.2, 89.8, 77.7, 76.2, 75.4, 75.1, 74.4, 72.2, 71.4, 69.1, 56.6, 51.8, 50.2, 49.2, 49.1, 41.7, 39.2, 37.4, 36.9, 33.3, 31.4, 30.4, 29.8, 28.5, 26.8, 26.6, 23.3, 22.9, 20.3, 18.2, 17.0, 16.0, 14.9, 13.5, 13.4, 12.4, 11.3, 7.1, 6.9 ppm. 1 1H NMR (403 MHz, CD2Cl2) δ ca. 13.00 (s, very br, 1H), 7.01 (d, J = 6.6 Hz, 1H), 6.09 (dd, J = 10.8, 2.7 Hz, 1H), 5.88 (dd, J = 10.7, 1.5 Hz, 1H), 4.70 (q, J = 12.1 Hz, 2H), 4.11 (ddd, J = 6.9, 2.6, 1.8 Hz, 1H), 4.07 (dd, J = 10.2, 0.9 Hz, 1H), 3.99 (dt, J = 8.7, 6.8 Hz, 3H), 3.94 - 3.86 (m, 3H), 3.57 (dd, J = 10.0, 2.0 Hz, 1H), 2.89 (td, J = 10.8, 4.1 Hz, 1H), 2.75 (dq, J = 9.7, 7.1 Hz, 1H), 2.63 (dd, J = 10.8, 2.0 Hz, 1H), 2.29 - 2.19 (m, 2H), 2.12 - 0.51 (m, 52H) ppm. ESI-MS (m / z): Calculated for C 45 H 72 Cl3NNaO 12 + [M + Na]+ calculated + 948.4; found 948.

[0091] (Example 14) Preparation of C20-dehydroxy-C20-aminosalinomycin N-propargylcarbamate having formula (22): [Chemical formula] The procedure was carried out in the same manner as in Example 1, except that propargyl chloroformate (10 mg, 1.2 eq) was added to the reaction mixture instead of acetyl chloride (1.2 eq). C20-dehydroxy-C20-aminosalinomycin N-propargylcarbamate having the formula (22) was obtained as a white amorphous solid in a 26% yield. Yield: 14 mg, 26%. Isolated as a white amorphous solid; purity >95% by single spot on NMR and TLC. Rf: 0.59 (ethyl acetate / n-hexane 50%). Green spot in phosphomolybdic acid (PMA). 13 C NMR (101 MHz, CD2Cl2) δ 215.1, 177.3, 155.8, 129.7, 122.8, 105.7, 99.7, 89.7, 78.8, 77.3, 76.4, 75.1, 74.4, 74.3, 72.1, 71.3, 69.2, 56.5, 52.6, 50.9, 49.7, 48.5, 41.5, 38.9, 37.3, 36.5, 33.1, 31.1, 30.6, 29.5, 28.5, 26.7, 26.4, 23.1, 22.7, 20.3, 18.0, 16.8, 15.9, 14.6, 13.4, 13.3, 12.1, 11.3, 7.1, 6.5 ppm. 1 H NMR (403 MHz, CD2Cl2) δ ca. 13.00 (s, very br, 1H), 6.68 (d, J = 6.9 Hz, 1H), 6.05 (dd, J = 10.8, 2.7 Hz, 1H), 5.83 (dd, J = 10.7, 1.5 Hz, 1H), 4.64 (dd, J = 15.6, 2.5 Hz, 1H), 4.54 (dd, J = 15.6, 2.5 Hz, 1H), 4.08 (ddd, J = 6.5, 3.3, 1.7 Hz, 2H), 4.00 - 3.83 (m, 4H), 3.58 (dd, J = 10.0, 1.7 Hz, 1H), 2.91 (td, J = 10.5, 4.2 Hz, 1H), 2.75 (ddd, J = 14.1, 9.8, 7.1 Hz, 1H), 2.58 (dd, J = 10.8, 1.5 Hz, 1H), 2.44 (t, J = 2.4 Hz, 1H), 2.19 (tt, J = 20.6, 10.3 Hz, 2H), 2.03 - 0.55 (m, 54H) ppm. ESI-MS (m / z): C 46 H73 NNaO 12 + [M+Na] calculated for + 854.5; measured value 854.

[0092] (Example 15) Preparation of propylurea of C20 - dehydroxy - C20 - aminosalinomycin having formula (23): [Chemical formula] Propyl isocyanate (18 mg, 3.0 equivalents) was added to a solution of C20 - aminosalinomycin (50 mg, 1.0 equivalent) in anhydrous methylene chloride (7 mL) at room temperature. This was stirred at room temperature until the reaction was complete, and the completion of the reaction was monitored by thin - layer chromatography TLC.

[0093] When the reaction was complete, the reaction mixture was washed with an aqueous solution of sodium bicarbonate (0.1 M). The organic layer was evaporated to dryness under reduced pressure, and the residue was purified using a CombiFlash (registered trademark) chromatograph equipped with an ELS detector and a solvent mixture of ethyl acetate:n - hexane with a rising gradient of ethyl acetate concentration from 0% to 100% using a silica - packed column. The combined fractions containing propylurea of C20 - dehydroxy - C20 - aminosalinomycin having formula (23) were evaporated to dryness under reduced pressure, the residue was dissolved in methylene chloride, and then extracted with an aqueous solution of sodium carbonate (0.1 M). The combined organic layers were evaporated to dryness again under reduced pressure and then repeatedly evaporated with n - pentane. Propylurea of C20 - dehydroxy - C20 - aminosalinomycin having formula (23) was obtained as a white amorphous solid in a 66% yield. Yield: 38 mg, 66%. Isolated as a white amorphous solid; purity > 95% by single spot of NMR and TLC. Rf: 0.64 (ethyl acetate / n - hexane 50%). Green spot in phosphomolybdic acid (PMA). 1313C NMR (101 MHz, CD2Cl2) δ 219.7, 185.0, 158.3, 130.3, 122.9, 107.2, 99.4, 88.9, 76.4, 76.3, 76.0, 74.4, 71.7, 71.4, 68.5, 56.7, 51.1, 50.3, 47.2, 42.5, 41.1, 39.2, 37.5, 36.4, 33.1, 33.0, 32.8, 30.3, 28.6, 28.3, 27.3, 24.13, 24.07, 20.5, 20.2, 17.8, 16.3, 16.1, 14.9, 13.4, 12.9, 12.5, 11.9, 11.1, 7.0, 6.8 ppm. 1 1H NMR (403 MHz, CD2Cl2) δ 6.06 (dd, J = 10.9, 3.0 Hz, 1H), 5.78 (t, J = 5.6 Hz, 1H), 5.68 (dd, J = 10.8, 1.9 Hz, 1H), 5.60 (d, J = 10.0 Hz, 1H), 5.55 (s, 1H), 4.88 (d, J = 4.8 Hz, 1H), 4.61 (ddd, J = 9.9, 2.9, 2.0 Hz, 1H), 4.31 (q, J = 6.9 Hz, 1H), 4.07 (ddd, J = 10.5, 4.7, 1.5 Hz, 1H), 3.81 (dd, J = 11.0, 4.7 Hz, 1H), 3.64 (dd, J = 10.1, 2.1 Hz, 1H), 3.60 (d, J = 10.2 Hz, 1H), 3.47 (dd, J = 12.4, 3.0 Hz, 1H), 3.05 - 2.97 (m, 2H), 2.82 (td, J = 11.1, 3.4 Hz, 1H), 2.76 - 2.66 (m, 2H), 2.25 - 0.50 (m, 59H) ppm. ESI-MS (m / z): C 46 H 78 N2NaO 11 + Calculated [M + H] for + 857.6; found 857.

[0094] (Example 16) Preparation of the butylurea of C20 - dehydroxy - C20 - aminosalinomycin having formula (24):

Chemical formula

[0095] (Example 17) Preparation of 3-chloropropylurea of C20-dehydroxy-C20-aminosalinosomycin having formula (25):

Chemical formula

[0096] (Example 18) Preparation of C20 - aminosalinomycin having formula (3):

Chem.

[0097] Once the reaction was complete, the reaction mixture was filtered through Celite. Subsequently, the filtrate was evaporated to dryness under reduced pressure, and the residue was purified using a CombiFlash® chromatograph equipped with an ELS detector using a silica-packed column and a solvent mixture of ethyl acetate:n-hexane with a rising gradient of ethyl acetate concentration from 0% to 50%. The combined organic layers containing C20-oxosalinomycin having formula (8) were evaporated to dryness again under reduced pressure and then repeatedly evaporated with n-pentane. C20-oxosalinomycin having formula (8) was obtained as a white amorphous solid (96 mg, 96% yield).

[0098] In the next step, an ammonia solution (7.0 N in methanol, 0.7 mL) was added to a solution of C20-oxosalinomycin (90 mg, 1.0 equivalent) having formula (8) in methanol (7 mL) at room temperature. This was mixed at room temperature for 5 hours, followed by the addition of CeCl3·7H2O (49 mg, 1.0 equivalent), and then, after 30 minutes, a solution of sodium cyanoborohydride, i.e., NaBH3CN (17 mg, 2.0 equivalents) in methanol (5 mL) was slowly added (overnight). The progress of the reaction was monitored using thin layer chromatography TLC.

[0099] Once the reaction was complete, the reaction mixture was evaporated to dryness under reduced pressure, and the residue was purified using a CombiFlash® chromatograph equipped with an ELS detector with a silica-packed column and a solvent mixture of acetone:chloroform with a rising gradient of acetone concentration from 0% to 60%. The combined organic layer containing C20-aminosalinomycin having the formula (3) was evaporated to dryness again under reduced pressure and then repeatedly evaporated with n-pentane. C20-aminosalinomycin having the formula (3) was obtained as a white amorphous solid in a yield of 42%. Yield: 38 mg, 42%. Isolated as a white amorphous solid; purity > 95% by single spot on NMR and TLC. Rf: 0.48 (acetone / methylene chloride 50%). Green spot in phosphomolybdic acid (PMA). 13 C NMR (101 MHz, CDCl3) δ 216.0, 182.4, 132.3, 128.7, 107.0, 99.7, 86.9, 77.5, 76.3, 75.8, 72.6, 71.8, 71.2, 67.9, 55.3, 51.5, 50.7, 48.2, 38.7, 37.5, 37.4, 36.5, 32.4, 31.3, 30.3, 29.5, 28.2, 26.9, 25.0, 24.1, 22.2, 20.6, 17.5, 16.5, 15.7, 15.1, 13.13, 13.09, 12.6, 11.2, 7.2, 6.6 ppm. 1 H NMR (403 MHz, CDCl3) δ 6.61 - 6.49 (m, 1H), 6.43 (d, J = 9.3 Hz, 1H), 5.98 (d, J = 46.8 Hz, 2H), 4.47 (d, J = 9.0 Hz, 1H), 4.29 (d, J = 62.7 Hz, 1H), 4.10 (d, J = 6.0 Hz, 1H), 3.90 (dd, J = 10.2, 3.1 Hz, 1H), 3.75 (d, J = 9.5 Hz, 1H), 3.68 - 3.54 (m, 2H), 3.39 (d, J = 28.4 Hz, 1H), 2.85 - 2.74 (m, 1H), 2.68 - 2.52 (m, 2H), 2.47 - 2.10 (m, 2H), 2.10 - 0.50 (m, 54H) ppm. ESI-MS (m / z): C 42 H 72 NO10 + [M+H] calculated for + 750.5; measured value 750.

[0100] (Example 19) Table 4 below summarizes the test results of C20-epi-salinomycin derivatives compared with the corresponding derivatives described in the present invention. The results shown clearly demonstrate that in all cases the epi-derivatives do not show higher activity than the corresponding derivatives described in the present invention. For some of the cell lines tested, the salinomycin derivatives in which the C-20 substituent is placed at the epi-position show a complete lack of activity and thus show a difference of more than two orders of magnitude compared to the derivatives described in the present invention. Table 4

Table 6

Claims

1. A compound or a salt thereof that constitutes a C20-N-acyl derivative of salinomycin, wherein the compound has the general formula (2): 【Chemical Formula 73】 (X represents R, O-R, or NH-R, where R is a linear or branched alkyl group containing 1 to 10 carbons, a linear or branched alkyl group containing 1 to 10 carbons, substituted with 1 to 5 halogens, which may be present on the same carbon or different carbons at any position of the carbon chain, a linear alkyl group containing 2 to 10 carbons, containing an ether moiety at any position of the carbon chain, a linear alkyl group containing 3 to 10 carbons, containing either a double bond or a triple bond at any position of the carbon chain, a monocyclic, bicyclic, or tricyclic alkyl group containing 5 to 10 carbons, an aromatic aryl group, an aromatic aryl group substituted with 1 to 3 substituents independently selected from alkyl, alkoxy, hydroxy, nitro, and nitrile groups, or halogens, an aromatic heteroaryl group in which one or more carbons are substituted with one or more heteroatoms from the group consisting of oxygen, nitrogen, or sulfur atoms, or an alkyl-aryl group in which the above-defined aromatic aryl group is linked to the salinomycin molecule by a carbon chain containing 1 to 5 carbons (alkyl containing 1 to 5 carbons)) (as shown), a compound or a salt thereof having the same.

2. The compound has the following formula: 【Chemical Formula 74】 【Chemical Formula 75】 【Chemical Formula 76】 【Chemical Formula 77】 【Chemical Formula 78】 [Chemical Formula 79] [Chemical Formula 80] [Chemical Formula 81] [Chemical Formula 82] [Chemical Formula 83] [Chemical Formula 84] [Chemical Formula 85] [Chemical Formula 86] [Chemical Formula 87] [Chemical Formula 88] [Chemical Formula 89] [Chemical Formula 90] The compound according to claim 1, or a salt thereof, having

3. The compound has the following formula: [Chemical Formula 91] [Chemical Formula 92] [Chemical Formula 93] [Chemical Formula 94] [Chemical Formula 95] [Chemical Formula 96] [Chemical Formula 97] The compound according to claim 1 or 2, or a salt thereof, having

4. The compound has the following formula: [Chemical Formula 98] The compound according to any one of claims 1 to 3, or a salt thereof, having

5. The compound has the following formula: [Chemical Formula 99] The compound according to any one of claims 1 to 3, or a salt thereof, having

6. A pharmaceutical composition comprising the compound according to any one of claims 1 to 5 or a salt thereof and at least one pharmaceutically acceptable excipient.

7. Formula (3): 【Chemical Formula 100】 A method for obtaining an intermediate product for obtaining the compound according to any one of claims 1 to 5 or a salt thereof, which constitutes C20 - aminosalinomycin having c) A step of chemoselective oxidation of the C20 - hydroxy group of salinomycin having 【Chemical Formula 101】 and d) Subsequently, a step of stereoselective reductive amination of the obtained C20 - oxosalinomycin having 【Chemical Formula 102】 wherein an alcoholic solution of ammonia is used as an aminating agent to bring about the in situ formation of an imine derivative, and then the imine derivative is reduced using sodium borohydride or a sodium borohydride derivative in the presence of a cerium salt. Step and A method comprising.

8. A method for obtaining the compound according to any one of claims 1 to 5 or a salt thereof, comprising Formula (3): C20 - aminosalinomycin having General formula (4): 【Chemical Formula 104】 an acid chloride having, or General formula (5): 【Chemical Formula 105】 a carboxylic acid having, or General formula (6): 【Chemical Formula 106】 a chloroformate having, or general formula (7): [Chemical 107] an isocyanate having (R is a linear or branched alkyl group containing 1 to 10 carbons, a linear or branched alkyl group containing 1 to 10 carbons, substituted with 1 to 5 halogens which may be present on the same carbon or on different carbons at any position of the carbon chain, a linear alkyl group containing 2 to 10 carbons, containing an ether moiety at any position of the carbon chain, a linear alkyl group containing 3 to 10 carbons, containing either a double bond or a triple bond at any position of the carbon chain, a monocyclic, bicyclic, or tricyclic alkyl group containing 5 to 10 carbons, an aromatic aryl group, an aromatic aryl group substituted with 1 to 3 substituents independently selected from alkyl, alkoxy, hydroxy, nitro, and nitrile groups, or halogens, an aromatic heteroaryl group in which one or more carbons are substituted with one or more heteroatoms from the group consisting of oxygen, nitrogen, or sulfur atoms, or an alkyl-aryl group in which the aromatic aryl group defined above is linked to the salinomycin molecule by a carbon chain containing 1 to 5 carbons (alkyl containing 1 to 5 carbons) (as shown)) reacting with, optionally, converting the resulting acid form of the compound to its salt, method.

9. a) In a first step, formula (1): [Chemical 108] chemoselective oxidation of the C20-hydroxy group of salinomycin having, followed by formula (8): [Chemical 109] By means of the stereoselective reductive amination of the obtained C20-oxosalinosomycin having the following formula, an intermediate having the formula (3): [Chemical formula 110] is obtained, b) In the second step, C20-aminosalinosomycin having the formula (3): [Chemical formula 111] and a general formula (4): [Chemical formula 112] an acid chloride having the following formula, or a general formula (5): [Chemical formula 113] a carboxylic acid having the following formula, or a general formula (6): [Chemical formula 114] a chloroformate having the following formula, or a general formula (7): [Chemical formula 115] an isocyanate having the following formula (R is a linear or branched alkyl group containing 1 to 10 carbons, a linear or branched alkyl group containing 1 to 10 carbons, substituted with 1 to 5 halogens which may be present on the same carbon or on different carbons at any position of the carbon chain, a linear alkyl group containing 2 to 10 carbons, containing an ether moiety at any position of the carbon chain, a linear alkyl group containing 3 to 10 carbons, containing either a double bond or a triple bond at any position of the carbon chain, a monocyclic, bicyclic, or tricyclic alkyl group containing 5 to 10 carbons, an aromatic aryl group, an aromatic aryl group substituted with 1 to 3 substituents independently selected from alkyl, alkoxy, hydroxy, nitro, and nitrile groups, or halogens, An aromatic heteroaryl group in which one or more carbons are substituted with one or more heteroatoms from the group consisting of oxygen, nitrogen, or sulfur atoms, or An alkyl-aryl group in which the aromatic aryl group defined above is linked to the salinomycin molecule by a carbon chain containing 1 to 5 carbons (alkyl containing 1 to 5 carbons) (as shown) By reacting with, general formula (2): [Chemical Formula 116] (X represents R, O-R, or NH-R, R is as shown above) A compound having is obtained, Optionally, comprising the step of converting the obtained compound in acid form to its salt, The method according to claim 8.

10. The compound according to any one of claims 1 to 5 or a salt thereof for use as a medicament.

11. The compound according to any one of claims 1 to 5 or a salt thereof for use according to claim 10 for use as an anti-cancer agent.

12. The compound or a salt thereof, in leukemia including acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma; non-small cell lung cancer including lung epithelial cell carcinoma, lung adenocarcinoma, human lung squamous cell carcinoma; colorectal cancer including colorectal adenocarcinoma, colonic epithelial cell carcinoma; tumors of the central nervous system including brain tumors such as glioma; melanoma including malignant melanoma, epithelial melanoma, non-epithelial melanoma; ovarian cancer including, but not limited to, epithelial ovarian cancer, ovarian cystadenocarcinoma; kidney cancer including renal cell carcinoma; prostate cancer including prostate adenocarcinoma; breast cancer including breast cancer, inflammatory breast cancer, metastatic adenocarcinoma; gastric cancer; pancreatic cancer; sarcoma and endometrial cancer, and drug-resistant types thereof; cervical cancer; for use in the treatment of a condition selected from the group consisting of bladder cancer, for use according to claim 10 or 11, the compound according to any one of claims 1 to 5 or a salt thereof.

13. The compound or a salt thereof according to any one of claims 1 to 5 for use in the treatment of a condition selected from the group including melanoma, colon cancer, breast cancer, and mixed leukemia, for the use according to any one of claims 10 to 12.

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