RU2056424C1 - Derivative of griseolic acid or its esters - Google Patents

Abstract

FIELD: organic chemistry. SUBSTANCE: products: 2-amino-6-desamino-6-hydroxygriseolic acid or its esters. Reagent 1: 6-desamino-2-(N′, N′-dimethylaminomethylene)-6-hydroxygriseolic acid dimethyl ether. Reagent 2: concentrated aqueous ammonia. Mixture is kept at the room temperature for 3 hr, evaporated until dry, residue is dissolved in water, acidified to pH 2.3 and purified by chromatography on column with RP-8. Synthesized compound is used in medicine. EFFECT: improved method of synthesis. 1 tbl

Description

 The invention relates to a number of new derivatives of griseolic acid and provides methods for producing these compounds and methods and compositions for their use.

 Griseolic acid is a nucleoside-type compound having a buildingin base and two carboxylic acid groups. It was first described inter alia in the specification [1] but its structure was not known at this stage.

 In accordance with the recommendations of the International Association of Pure and Applied Chemistry (GIRAS), the compounds of the invention are named as derivatives of griseolic acid (or dihydrodeoxygryzeolic acid), taking griseolic acid as the starting structure.

 Griseolic acid and derivatives of griseolic acid exhibit the ability to inhibit the activity of phosphodiesterase specific for various cyclic nucleotides, for example 3 ', 5'-cyclic adonosine monophosphate (cAMP) phosphodiesterase (PDE) or 3', 5'-guanosine monophosphate (cCP) (PDM) and may increase the level of a cyclic nucleotide, for example, cAMP or cGMP, in the cells of the patient to which such a compound is applied.

 It is known that cAMP, which is very well distributed in animal tissues, functions as a second carrier and occupies an intermediate position in action for a large number of hormones; as a result, cAMP has various very important physiological and biochemical values. In addition, it is known that it acts on or takes part in cell division, proliferation and differentiation, the systolic system, especially the myocardium, hematoposis, various functions of the central nervous system, immune reactions; and the release of insulin and histamine. Its concentration in the tissues and, therefore, its effect on these various functions depends on the balance between the enzyme that synthesizes cAMP (i.e. adenylate cyclase) and the enzyme that breaks down cAMP, cGMP PDE. The protin cAMP PDE inhibitor will increase the level of cAMP in cells and can be used for various therapeutic purposes, for example, in the treatment of cardiovascular diseases, as an antiasmatic agent, as a muscle relaxant, as a psychotropic or neutrotropic agent, as an anti-inflammatory agent, in cancer therapy and for treatment diabetes.

 The functions of the effects of other cyclic nucleotides, for example, cAMP, are currently less studied. However, they have an activity region that is the same, although not identical, as cAMP. Therefore, inhibition of PDEs specific for other cyclic nullotides will lead to a range of therapeutic effects similar to those due to inhibition of cAMP PDE. Since the functions of the effects of other cyclic nucleotides are under explanation, there is a need to inhibit PDEs associated with other nucleotides whose inhibitors exhibit increased specificity for certain PDEs of other nucleotides, rather than PDE, indeed, the development of such inhibitors may even help or stimulate research such cyclic nucleotides.

 In addition to griseolic acid and its derivatives, other compounds are known to inhibit cAMP and cGMP PDEs and these compounds include papaverine, dipyridamo and some compounds that are compound nucleic acid bases, such as terfilin or MSB 22, 948 (Kukovetz et al , Poipup Schmiedebrig; s itrch Pharmakol; 310, 1291, 1979).

 The Applicant has discovered a number of compounds which relate to griseolic acid and dihydrodeoxygryzeolic acid which have the activity of griseolic acid and dihydrodeoxygryzeolic acid. Some of these compounds unexpectedly show increased activity against cGMP PDE than against cAMP PDE. Some compounds of the invention, while retaining the target activity, are more valuable as intermediates in the preparation of other appropriate target compounds.

 Compounds of the invention are compounds of formula I.

(I)
Соединения изобретения могут использоваться в фармацевтических композициях, включающих ингибитор фосфодиэстеразы в смеси с фармацевтическим приемлемым носителем или разбавителем, где указанный ингибитор фосфодиэстеразы выбирают из группы, состоящей из соединений формулы (I), как определено выше, и фармацевтически приемлемых солей и сложных эфиров этих соединений.

(I)
The compounds of the invention can be used in pharmaceutical compositions comprising a phosphodiesterase inhibitor in admixture with a pharmaceutically acceptable carrier or diluent, wherein said phosphodiesterase inhibitor is selected from the group consisting of compounds of formula (I) as defined above and pharmaceutically acceptable salts and esters of these compounds.

 The compounds of the invention are used to treat animals, especially mammals (e.g., humans), suffering from a disorder caused by an imbalance in phosphodiesterase levels by applying a phosphodiesterase inhibitor to said animals, wherein said phosphodiesterase inhibitor is selected from the group consisting of compounds of formula (I), as defined above, and pharmaceutically acceptable salts and esters of these compounds. The compounds of formula (I) contain two carboxyl groups and can thus form mono- or di-salts and mono- or di-esters. In the case of di-salts and di-esters, the cationic fragments of salts or alcohol fragments of esters may be the same or different. However, in practice, it is most easy to prepare di-salts or di-esters in which two cationic moieties or two alcohol moieties are the same.

There is no particular restriction on the nature of the alcohol fragment of the ester, provided that when the compound is intended for therapeutic use, this fragment must be pharmaceutically acceptable, which means that it does not reduce or decreases to an acceptable extent the activity of the compound or its toxicity and all esters, suitably prepared for compounds of this type can be formed with the compounds of the invention. If esters are not intended for therapeutic use (for example, as intermediates), even this limitation is not required. Examples of such esters include C _1-6 esters, especially methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl esters; aralkyl esters, especially benzyl, para-nitrobenzyl. ortho-nitrobenzyl, triphenylmethyl, bis- (ortho-nitrophenyl) methyl, 9-anthrylmethyl, 2,4,6-trimethylbenzyl, para-bromobenzyl, para-methoxybenzyl, piperonyl and benzhydride esters; C _1-6 haloalkyl esters which may have 1 or more halogens (e.g. chlorine, bromine, fluorine, illiod), up to complete perhalogenation, e.g. 2,2,2-trichloroethyl, 2-chloroethyl, 2-bromoethyl, 2 -fluoroethyl, 2-iodoethyl and 2,2-dibromethyl esters; alkoxymethyl esters, where the alkoxy portion preferably consists of C _1-4 , for example methoxymethyl, ethoxymethyl, propoxymethyl, isopropoxymethyl and butoxymethyl, esters, aliphatic acyloxyalkyl esters (especially acyloxymethyl and acyloxyethyl esters), such as acetone butyryloxymethyl, pivaloyloxymethyl, 1-acetoxyethyl, 1-propionyloxyethyl, 1-butyryloxyethyl and 1-pivaloyloxyethyl esters, (C _1-4 alkyl) oksikarboniloksietil-esters such as 1-methoxycarbonyloxyethyl, 1-ethoxy arbonyloxyethyl, 1-propoxycarbonyloxyethyl, 1-isopropoxycarbonyloxyethyl, 1-butoxycarbonyloxyethyl and 1-isobutoxycarbonyloxyethyl esters, heterocyclic esters, such as phthalidyl esters, heterocyclomethyl esters, for example, (2-5-methyl-ether) , 3-dioxolen-4-yl) methyl esters, and esters that are easily hydrolyzed in vivo, the class of which includes some esters of the classes mentioned above (e.g., aliphatic acyloxyalkyl esters, lower alkoxy-carbonyloxyethyl esters (5 -met l-2-oxo-1,3-dioxolen-4-yl) methyl esters and phthalidyl esters).

 The compounds of the invention have a number of asymmetric carbon atoms in their molecules and can therefore exist in the form of various stereoisomers. The invention includes both individual isomers and mixtures of these isomers. Griseolic acid, being a natural product, is the only isomer in which both 2 'and 7' carbon atoms are in the R configuration, compounds derived from griseolic acid may retain the same configuration or may have an inverted configuration at one or more asymmetric atoms carbon.

(II) где R¹ карбоксизащищающая группа;
R² защищенная метиленовая группа, с солью азотистой кислоты в водном растворе уксусной кислоты при комнатной температуре в течение 7 ч и в полученном соединении общей формулы III

(III) где R¹ и R² имеют приведенные значения, удалением защитных групп обработкой основанием в присутствии водного растворителя при комнатной температуре в течение 3 ч.Compounds of the invention are prepared by the reaction of a compound of formula II

(II) where R ^{1 is a} carboxy protecting group;
R ² protected methylene group, with a salt of nitrous acid in an aqueous solution of acetic acid at room temperature for 7 hours and in the obtained compound of General formula III

(III) where R ¹ and R ² are as indicated, by removing the protective groups by treatment with a base in the presence of an aqueous solvent at room temperature for 3 hours

Such a reaction is preferably carried out by reacting griseolic acid or protected griseolic acid with a nitrous acid salt, for example sodium nitrite, in the presence of acetic acid. Such a reaction is preferably carried out in the presence of a solvent, the nature of which is not critical, and in this regard, the reaction is usually carried out using an aqueous solution of acetic acid. If the starting compound has only insignificant solubility in acetic acid, an acetic acid buffer having a pH of about 4 can be used. The reaction will proceed over a wide temperature range, although it is more convenient to carry out at a temperature close to room temperature. The time required for the reaction can vary widely depending on many factors, mainly on the nature of the reagents and the reaction temperature, however, at the recommended temperature, it is sufficient to carry out the reaction for 15-50 hours. In the next step, the mixed methylene group protected by 2 the zamino amino group is removed together with both carboxy protecting groups R ¹ to form a compound of formula (I). In the case where a substituted methylene group is used as the amino protecting group, such a group can be removed by treatment with a base in the presence of an aqueous solvent. There is no particular restriction on the nature of the solvent used; any solvent conventionally used for hydrolysis can be used for this reaction. Examples of preferred solvents include water and mixtures of water with one or more organic solvents, for example, such as alcohols, for example methanol, ethanol or propanol, ethers, for example tetrahydrofuran or dioxane. There is no particular restriction on the nature of the base, provided that it does not affect other fragments of the molecule. Examples of suitable bases are alkali metal carbonates, for example sodium carbonate or potassium carbonate, alkali metal hydroxides, for example sodium hydroxide or potassium hydroxide, and a methanolic ammonia solution. The most preferred bases for removing protecting groups from the nucleic acid base are methanolic ammonia solutions; in other cases, an aqueous solution of sodium hydroxide is preferred. The reaction is carried out in a wide temperature range and selection of a particular temperature is not critical, but the reaction is preferably carried out at ambient or reduced temperature, for example at a temperature in the range of from 0 ° ^C to room temperature. The time required for the reaction can vary over a wide range depending on many factors, mainly the nature of the starting materials and the reaction temperature. However, under these conditions, the reaction is usually completed in 1-10 hours. Removal reactions of amino protecting groups may be accompanied by simultaneous elution of the carboxy protecting groups. The order in which the hydroxyl protected groups, carboxy protecting groups or amino protecting groups are eluted is not critical, and the removal of such groups can be carried out in any order, sequentially or simultaneously. After completion of any of the described reactions, the target product from each of these stages can be isolated from the reaction mixture by conventional methods. For example, the reaction mixture is washed with water if necessary, and then the solvent is distilled off under reduced pressure. The residue can be purified by various methods, such as recrystallization and various chromatographic techniques, for example on a chromatographic column or using preparative thin layer chromatography to obtain the target compound.

 Inhibitory activity of phosphodiesterase (PDE).

 Some compounds of the invention were tested (hereinafter indicated by the numbers of examples) along with theophylline as a comparative compound.

The test was carried out practically in accordance with a method similar to the method [3]
The crude enzyme solution obtained from rat brain was used as a source of cAMP PDE. As a substrate, ¹⁴ C-labeled cAMP was used. It was used in a buffer of 0.2 M Tris-hydrochloric acid pH 8.0 in an amount sufficient to obtain a final concentration of 0.14 μM. Tris is tris (oxymethyl) aminomethane. The substrate solution is mixed with an appropriate amount of the compound used, dissolved in a volume of 2.0 to 5.0 μl of dimethyl sulfoxide and with 20 μl of snake venom solution and 40 μl of the crude enzyme solution. A sufficient amount of Tris-hydrochloric acid buffer is added until a total volume of 100 μl is obtained. The resulting mixture was allowed to react at 30 ^{° C} for 20 min. At the end of this period of time, the reaction mixture is treated with Amberlit (brand) IRP-58 resin and the level of remaining adenosine radioactivity in the product is determined. The experiment is carried out for a number of different concentrations for each active compound, and from here the 50% inhibition values are calculated (I ₅₀ ).

The experiment is repeated, except that instead of cAMP cyclic guanosine monophosphate (cGMP) is used, I ₅₀ values are again calculated depending on cGMP PDE.

 The results are presented in the table.

 The table shows that the activity of the compounds of the invention as PDE inhibitors is extremely high. The differences in activities against cAMP PDE and cGMP PDE are also clearly visible.

 Thus, various therapeutic applications of the compounds are possible, for example, in the treatment of cardiovascular diseases, as anti-asthma agents, as smooth muscle relaxants, as psychotropic or neurotropic agents, as anti-inflammatory agents in the treatment of cancer and in the treatment of diabetes.

 The compounds of the invention can also be used as therapeutic agents in various cerebral circulatory disorders, such as cerebral consequences of a stroke and as activators of metabolism in the brain, for example, in the treatment of senile paralysis or traumatic brain lesions. The compounds of the invention can be administered orally or non-orally (for example, subcutaneously or intramuscularly). The compounds of the invention can be administered orally in the form of solid preparations, which may optionally contain various kinds of conventional additives. These additives include diluents such as sugars and cellulose preparations such as binders such as starch, resins and methylene cellulose, distribution agents. Doses may vary depending on the symptoms of the disease, the age and weight of the patient, for example, in the case of adults.

 PRI me R 1. 5-Desamino-2- (N ', N'-dimethylamiomethylene) amino-6-hydroxygryzeolic acid dimethyl ether.

 477 g of dimethyl long-life 2- (N ', N'-dimethylaminomethylene) aminogrizeolic acid ester is dissolved in 50 ml of an aqueous solution of acetic acid (80 vol.). While cooling with ice, 1.34 g of sodium nitrite was added, the mixture was allowed to stand for 17 hours at room temperature. After the disappearance of the starting material, which is controlled by thin layer chromatography, the solvent is distilled off under reduced pressure. Ethanol is added and then it is distilled off, and these addition and distillation operations are repeated until the smell of acetic acid disappears. The residue is dissolved in a mixture of 50 ml of methylene chloride, 20 ml of water and 5 l of an aqueous solution of sodium bicarbonate (5 g in 100 ml). The organic layer was separated and extracted 3 times with 30 ml of methylene chloride each, and the extracts were combined. The solvent was distilled off under reduced pressure. The residue is purified using a chromatographic column (F. Merck), pre-filled with silica gel and eluted with methylene chloride containing 10 vol. methanol. The main fractions were collected and freeze-dried from benzene to give 310 mg of the title compound as a white powder.

UV absorption spectrum (in methanol), λ _max. nm: acid 292, neutral 300, basic 279.

 PRI me R 2. 2-Amino-6-desamino-6-hydroxygryzoleic acid.

 130 mg of 6-desamino-2- (N ′, N′-dimethylaminomethylene) amino-6-hydroxygryzeolic acid dimethyl ether (prepared as described in Example 1) was dissolved in 20 ml of concentrated aqueous ammonia, and the mixture was allowed to stand at room temperature for 3 hours. The solution was evaporated dry under reduced pressure, and the residue was dissolved in 10 ml of water. The resulting solution was acidified to pH 2.3, then subjected to chromatographic purification on a pre-filled RP-8 column (F. Merck), which was washed with water and then eluted with water containing 5 vol. acetonitrile. The main fractions were collected and lyophilized to give 67 mg of the title compound as a white powder.

UV absorption spectrum (in water), λ _max. nm: acid 255, 273 (shoulder), neutral 253, 278 (shoulder); main 264, NMR spectrum (in deuterium dimethyl sulfoxide). ppm 4.48 (1H, singlet), 4.53 (1H, doublet, I) 4, Hz), 5.07 (1G, d. I 2.4 Hz), 5.79 (1H, dd I 2.4 and 4.9 Hz), 6.25 (1H, s. 7.87 (1H, s).

Thin layer chromatography (relative value of R _f , for griseolic acid Rj (taken as 1.0). For silica gel plate (F. Merck) 0.80 (eluting solvent water: methanol: acetonitrile 70: 15: 15 by volume (for plate PP- 8 with the reverse phase (F. Merck) 1.44 (water eluting solvent containing 2 vol; acetonitride and 0.02 vol. Acetic acid).

Claims (1)

A derivative of griseolic acid of the formula

or its esters.

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