134~z TITLE OF THE INVENTION
HMG-CoA REDUCTASE INHIBITORS
This Application is a Divisional Application of Canadian Patent Application Serial Number 540,097, filed June 19, 1997.
BACKGROUND OF THE INVENTION
Hypercholesterolemia is known to be one of the prime risk factors for atherosclerosis and coronary heart disease, the leading cause of death and disability in western countries. To date, there is still no effective antihypercholesterolemic agent commercially available that has found wide patient acceptance. The bile acid sequestrants seem to be moderately effective but they must be consumed in large quantities, i.e., several grams at a time, and they are not very palatable.
There are agents known, however, that are very active antihypercholesterolemic agents which 1340 i5~
function by limiting cholesterol biosynthesis via inhibiting the enzyme, HMG-CoA reductase. These agents inclu~e the natural fermentation products compactin and mevinolin and a variety of S semi-synthetic and totally synthetic analogs thereof. The naturally occurring compounds and their semi-synthetic analogs have the following general structural formulae:
~ or Rl R
wherein: Z is hydrogen, Cl_5 alkyl or Cl_5 alkyl substituted with a member of the group consisting of phenyl, dimethylamino, or acetylamino; and O Rl iS:
C~3 ~ 13 wherein Q is R3-C- or R3-CH; R3 is H or OH; and R2 is hydrogen or methyl; and a, b, c, and d 1~0452 represent optional double bonds, especially where b and d represent double bonds or a, b, c, and d are all single bonds.
U.S. Patent 4,517,373 discloses semi-synthetic hydro~y containing compounds represented by the above general formula wherein Rl is 8 ~ Z Cl,lo.l~ Z
~d C~3 0~
U.S. Patent 4,537,859 and U.S. Patent 4,448,979 also disclose semisynthetic hydro~y-containing compounds represented by the above general formula wherein Rl is ~ ~ ~ ~ ~ J
These compounds are prepared by the action of certain microorganisms on the corresponding non-hydro~ylated substrates, One such organism , ..... . _ _, . . . . .
. -- 4 described in U.S. 4,537,859 is of the genus Nocardia.
U.S. Patent 4,376,863 discloses a fermentation product, isolated after cultivation of a microorganism belonging to the genus Aspergillus, which has a hydroxy-containing butyryloxy side chain and is represented by the above general formula wherein R1 is ~ Y 2 ~ 33 C~3~ ~
Japanese unexamined Patent Application J59-122,483-A (July 1984) discloses a semisynthetic hydroxy-containing compound represented by the above general formula wherein R1 is CH ~ 2 ED ~ H3 1- - 5 - 13~0452 SUMMARY OF THE INVENTION
This invention relates to novel compounds which are HMG-CoA reductase inhibitors and are useful as antihypercholesterolemic agents. - Specifically, the compounds of this invention are analogs of mevinolin and related compounds which possess a hydroxymethyl group or a carboxy group on the 6-position of the polyhydronaphthyl moiety. Methods are disclosed of treating disease conditions in which hypercholesterolemia is an etiological factor, and processes for preparing the novel compounds.
In other aspects there is provided use of the novel compounds as an anti-hypercholesterolenic agent or as a HMG-CoA reductase inhibitor.
In still another aspect there is provided novel compounds of the invention for use in the treatment of atherosclerosis and coronary heart disease.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention there is provided a compound represented by the following general structural formula (X):
--~R'' ~,R'5 O
R'~O ~
~C~
(x) R --1340~52 wherein: R14 is -COOH and R15 is OH or R14 and R15 together form a chain -C,-O-, R is CH20H or COOH; and R1 is sec-butyl, or a pharmaceutically acceptable salt thereof.
It will be recognized that when R14 and R15 together form the -CI-O- chain, the resulting compound of formula (X) is the ring closed lactone or pyranone form of the dihydroxy acid of formula (X) in which R14 is -COOH and R15 is OH. The lactone form is shown as formula (I) below.
The specific HMG-CoA reductase inhibitors of this invention are the compounds represented by the following general structural formulae (I) and (II):
~ ~ C~2 H
R CQ . RlCO
R C~3 R CX3 (I) (II) wherein: R is CH20H or COOH, and R1 is sec-butyl or a pharmaceutically acceptable salt thereof.
More specifically examples of compounds of the invention are the following compounds:
.. ........ .. ... ...
_ 7 _ 13~0~S2 (1) 6 (R) - [2-[8(S)-(2-methylbutyryloxy)-2(S)-methyl-6(S)-hydroxymethyl-1,2,6,7,8,8a (R) -hexa-hydronaphthyl-l(S)]ethyl]- 4 (R) - hydroxy-3,4,5,6-tetra-hydro-2H-pyran-2-one;
(2) 6 (R) - [2-[8(S)-(2-methylbutyryloxy)-2(S)-methyl-6(S)-carboxy-1,2,6,7,8,8a (R) -hexahydronaphthyl-l(S)]ethyl] -4 (R) -hydroxy-3, 4, 5,6-tetrahydro-2H-pyran-2-one;
(3) 6 (R) - [2-[8(S)-(2-methylbutyryloxy)-2(S)-methyl-6 (R) -hydroxymethyl-1,2,6,7,8,8a (R) -hexahydro-naphthyl-l(S)]ethyl]-4 (R) -hydroxy-3, 4, 5, 6-tetrahydro-2H-pyran-2-one;
and the corresponding ring opened dihydroxy acids, and pharmaceutically acceptable salts thereof.
The compounds of formulae (I) and (II) are conveniently prepared from mevinolin or its analogs having a 6-methyl group by one of three methods:
(a) adding the substrate to a growing culture of Nocardia autotrophica for a suitable incubation period followed by isolation, and derivatization if desired;
(b) collecting a culture of the bioconverting micro-organism and contacting the collected cells with the substrate; or (c) preparing a cell-free, enzyme-containing extract from the cells of the bioconverting microorganism and contacting this extract with the substrate.
- 8 - 1340i~2 Cultivation of the bioconverting microorganism of the genus Nocardia can be carried out by conventional means in a conventional culture medium containing nutrients well known for use with such microorganisms.
Thus, as is well known, such culture ~ . 13~52 media contain sources of assimilable carbon and of assimilable nitrogen and often inorganic salts.
E~amples of sources of assimilable carbon include glucose, sucrose, starch, glycerin, millet jelly, molasses and soybean oil. Examples of sources of assimilable nitrogen include soybean solids (including soybean meal and soybean flour), wheat germ, meat e~tracts, peptone, corn steep liquor, dried yeast and ammonium salts, such as ammonium sulphate. If required, inorganic salts, such as sodium chloride, potassium chloride, calcium carbonate or phosphates, may also be included. Also, if desired, other additives capable of promoting the production of hydroxylation enzymes may be employed in appropriate combinations. The particular cultivation technique is not critical to the process of the invention and any techniques conventionally used for the cultivation of microorganisms may equally be employed with the present invention. In general, of course, the techniques employed will be chosen having regard to industrial efficiency. Thus, liquid culture is generally preferred and the deep culture method is most convenient from the industrial point of view.
Cultivation will normally be carried out under aerobic conditions and at a temperature within the range from 20~ to 37~C., more preferably from 26~
to 28~C.
Method (a) is carried out by adding the substrate to the culture medium in the course of cultivation. The precise point during the cultivation at which the starting compound is added will vary depending upon the cultivation equipment, .
1~0452 composition of the medium, temperature of the culture medium and other factors, but it is preferably at the time when the hydroxylation capacity of the micro-organism begins to increase and this is usually 1 or 2 days after beginning cultivation of the micro-organism. The amount of the substrate added is preferably from 0.01 to 5.0% by weight of the medium, more preferably from 0.05 to 0.5~-0, e.g., from 0.05 to 0.1% by weight. After addition of the substrate, cultivation is continued aerobically, normally at a temperature within the ranges proposed above.
Cultivation is normally continued for a period of from 1 to 2 days after addition of the substrate.
In method (b), cultivation of the micro-organism is first carried out under conditions such as to achieve its maximum hydroxylation capacity;
this capacity usually reaches a maximum between 4 and 5 days after beginning the cultivation, althoush this period is variable, depending upon the nature and temperature of the medium, the species of micro-organism and other factors. The hydroxylation capacity of the culture can be monitored by taking samples of the culture at suitable intervals, deter-mining the hydro~ylation capacity of the samples by contacting them with a substrate under standard conditions and determining the quantity of product obtained and plotting this capacity against time as a graph. When the hydroxylation capacity has reached its maximum point, cultivation is stopped and the microbial cells are collected. This may be achieved by subjecting the culture to centrifugal separation, filtration or similar known separation methods. The whole cells of the cultivating microorganism thus collected, preferably, are then washed with a .. ..
1340~2 suitable washing liquid, such as physiological saline or an appropriate buffer solution.
Contact of the collected cells of the micro-organism of the genus Nocardia with the substrate is generally effected in an aqueous medium, for example in a phosphate buffer solution at a p~ value of from 5 to 9. The reaction temperature is preferably within the range from 20~ to 45~C., more preferably from 25~
to 30~C. The concentration of the substrate in the reaction medium is preferably within the range from 0.01 to 5.0% by weight. The time allowed for the reaction is preferably from 1 to 5 days, although this may vary depending upon the concentration of the substrate in the reaction mixture, the reaction tem-perature, the hydroxylation capacity of the micro-organism (which may, of course, vary from species to species and will also, as explained above, depend upon the cultivation time) and other factors.
The cell-free, enzyme-containing extract employed in method (c) may be obtained by breaking down the whole cells of the microorganism obtained as described in relation to method (b) by physical or chemical means, for example by grinding or ultrasonic treatment to provide a disintegrated cellular mass or by treatment with a surface active agent or an enzyme to produce a cellular solution. The resulting cell-free extract is then contacted with the substrate under the same conditions as are described above in relation to method (b).
- - The microorganism useful in the novel process of this invention is of the genus Nocardia.
Of particular importance are the known strains of microorganism, Nocardia autotrophica, subspecies canberrica, ATCC 35203 of the culture MA-6181 and .
- 13~0~2 subspecies amethystina ATCC 35204 of the culture MA-6180 of the culture collection of Merck & Co., Inc., Rahway, New Jersey. ATCC 35203 and 35204 both have deposit dates of May 25, 1983.
It should be noted that the culture MA-6180 preferentially affords the hexahydronaphthyl compounds of this invention wherein R is CH2OH, although the compounds wherein R is CO2H are also formed. Additionally, when the culture MA6181 is utilized in the bioconversion reaction, the compounds of the invention wherein R is CO2H are preferentially formed, although the compounds wherein R is CH2OH are also prepared. Samples of the cultures designated ATCC 35203 and ATCC 35204 are available in the permanent culture collection of the American Type Culture Collection at 12301 Parklawn Drive, Rockville, MD 20852.
A novel microorganism deposited in the culture collection of Merck & Co., Inc. and designated MA-6455 may also be utilized in the bioconversion reaction.
After completion of the conversion reaction by any of the above methods, the desired compound can be directly isolated, separated or purified by conventional means. For example, separation and purification can be effected by filtering the reaction mixture, extracting the resulting filtrate with a water-immiscible organic solvent (such as ethyl acetate), distilling the solvent from the extract, subjecting the resulting crude compound to column chromatography, (for example, on silica gel or alumina) and eluting the column with an appropriate eluent, especially in an HPLC apparatus.
The compounds of formula (I) wherein R is CO2H
can be 1340i52 converted cleanly, and without epimerization of the methine group to which R is appended, to the corresponding primary alcohols wherein R is CH20H
as illustrated in the following synthetic pathway:
O - O
, ~2C
(1) (2) ~0~
O ,' -- O
~0 ~ /~\0 ~, HOC~ ~ (CH3)2CHCH20CCC
(4) (3) Compound (1) is converted to the corresponding triethylammonium salt (2) in a suitable organic solvent, preferably methylene chloride at room temperature. Without isolation but with cooling, preferably to -70ac, compound (2) is allowed to react with isobutyl chloroformate to afford the mixed anhydride (3). The resulting, cold solution of compound (3) is added to a cold, preferably 0~C, solution o~ a suitable reducing agent, such as ..... .........
13~q~52 sodium borohydride, in a suitable organic solvent, such as ethanol, to afford compound (4).
Where the product formed by the above described microbiological or synthetic pathways is not the desired form of that compound, then that product may be subjected to one or more further reactions such as hydrolysis, salification, esterification, acylation, ammonolysis or lactonization by conventional methods, as described in more detail hereafter. Such additional reactions may be carried out prior to, after or in the course of the separation and purification stages described above, preferably in the course of these stages.
The starting compound may be a free carboxylic acid, its corresponding lactone or a salt (e.g., metal, amino acid or amine salt) or ester (particularly alkyl ester) thereof.
Preferred metal salts are salts with the alkali metals, such as sodium or potassium, salts with alkaline earth metals, such as calcium, or salts with other metals such as magnesium, aluminum, iron, zinc, copper, nickel or cobalt, of which the alkali metal, alkaline earth metal, magnesium or aluminum salts are preferred, the sodium, calcium and aluminum salts belng most preferred.
Preferred amino acids to form amino acid salts are basic amino acids, such as arginine, lysine, histidine, a,~-diaminobutyric acid or ornithine.
Preferred amines to form amine salts include t-octylamine, dibenzylamine, dichlorohexylamine, morpholine, alkyl esters of D-phenylglycine and D-glucosamine. Also preferred is ammonia to form the ammonium salt.
Of the starting materials, the alkali metal salts, e.g., the sodium or potassium salts, are particularly preferred, the sodium salt being most ..... .... _, ...
- 15 - 13~0~2 preferred as it has been found that this gives the best conversion of the substrate into the desired product.
Where the product obtained by the processes of the present invention is a salt of the carboxylic acid of formula (II), the free carboxylic acid itself can be obtained by adjusting the pH of the filtrate to a value of 4 or less, preferably to a value of from 3 to 4. Any organic acid or mineral acid may be employed, provided that it has no adverse effect upon the desired compound.
Examples of the many acids which are suitable include trifluoroacetic acid, acetic acid, hydrochloric acid and sulphuric acid. This carboxylic acid may itself be the desired product or it may be, and preferably is, subjected to subsequent reactions, as described below, optionally after such treatments as extraction, washing and lactonization.
Metal salts of the carboxylic acids of formula (II) may be obtained by contacting a hydroxide, carbonate or similar reactive compound of the chosen metal in an aqueous solvent with the carboxylic acid of formula (II).
The aqueous solvent employed is preferably water, or it may be a mixture of water with an organic solvent, preferably an alcohol (such as methanol or ethanol), a ketone (such as acetone), an aliphatic hydrocarbon (such as hexane) or an ester (such as ethyl acetate). It is preferred to use a mixture of a hydrophilic organic solvent with water. Such reactions are normally conducted at ambient temperature but they may, if desired, be conducted with heating.
Amine salts of the carboxylic acids of formula (II) may be obtained by contacting an amine in an aqueous solvent with the carboxylic acid of formula (II).
Suitable aqueous solvents include water and mixtures of water with alcohols (such as methanol or ethanol), ethers (such as tetrahydrofuran), nitriles (such as 1340~
acetonitrile) or ketones (such as acetone); it is preferred to use aqueous acetone as the solvent for this reaction. The reaction is preferably carried out at a temperature of ambient or below, more preferably a temperature of from 5~ to 10~C. The reaction immediately goes to completion. Alternatively, a metal salt of the carboxylic acid of formula (II) (which may have been obtained as described above) can be dissolved in an aqueous solvent, after which a mineral acid salt (for example, the hydrochloride) of the desired amine is added, employing the same reaction conditions as when the amine itself is reacted with the carboxylic acid of formula (II) and the desired product is then obtained by a salt exchange reaction.
Amino acid salts of the carboxylic acids of formula (II) may be obtained by contacting an amino acid in aqueous solution with the carboxylic acid of formula (II). Suitable aqueous solvents include water and mixtures of water with alcohols (such as methanol or ethanol) or ethers (such as tetrahydrofuran).
Lactones of the carboxylic acids of formula (I) may be obtained by lactonizing the carboxylic acids of formula (II) under ordinary conditions known to one skilled in the art.
The compounds of this invention are useful as antihypercholesterolemic agents for the treatment of arteriosclerosis, hyperlipidemia, familial hypercho-lesterolemia and like diseases in humans. They may be administered orally or parenterally in the form of a capsule, a tablet, an injectable preparation or the like.
It is usually desirable to use the oral route. Doses may be varied, depending on the age, severity, body weight and other conditions of human patients but daily dosage for adults is within a range of from about 2 mg to 2000 mg (preferably 10 to 100 mg) which may be given in two to 1340~52 four divided doses. Higher doses may be favourably employed as required.
The intrinsic HMG-CoA reductase inhibition activity of the claimed compounds is measured in the in vitro protocol published in J. Med. Chem., 28, p. 347-358 (1985) and described below:
1 3 40 i~2 Isolation of HMG-CoA Reductase Male Holtzman Sprague-Dawley rats (225-250 g) were kept on reversed lighting and fed Purina rat chow containing 3% cholestyramine for 7 days preceding their sacrifice by CO2 asphy~iation. Livers were removed 6 hours into the dark cycle and used immediately to prepare microsomes. HMG-CoA reductase was solubilized from the freshly prepared microsomes by the method of Heller and Shrewsbury [J. Biol.
Chem., 1976, 251, 3815] and purified through the second ammonium sulfate precipitation step as described by Rleinsek et al. [Proc. Natl. Acad. Sci.
USA, 1977, 74, 1431]. The enzyme preparation was tested for HMG-CoA reductase potency and diluted with 100 mM phosphate buffer (pH 7.2) so that 100 ~1 of the enzyme solution, when added to the assay control, gave a value of 50,000-60,000 dpm. The enzyme preparation was stored at -80~C.
HMG-CoA Reductase Inhibition Assay The assay is essentially the procedure of Shefer et al. [J. Lipid Res., 1972, 13, 402]. The complete assay medium contained the following in a total volume of 0.3 ml: phosphate buffer, pH 7.2, 100 mM; MgC12, 3 mM; NADP, 3 mM; glucose-6-phosphate, 10 mM; glucose-6-phosphate dehydro-genase, 3 enzyme units; reduced glutathione, 50 mM;
HMG-CoA (glutaryl-3- C, New England Nuclear), 0.2 mM (O.1 ~Ci); and partially purified enzyme stock solution, 100 ~L.
Test compounds or compactin, after first being converted to the sadium salt of their dihydroxy acid form in situ by addition of lN NaOH (i equivalent), were added to the assay system in 10-~L volumes at multiconcentration levels. After a 40-minute incubation at 37~C with shaking and e~posure to air, the reaction was stopped by the addition of 0.4 mL of 8 N HCl. After an additional 30-minute incubation period at 37~C to ensure the complete lactonization of mevalonic acid to mevalonolactone, 0.2 ml of the mi~ture was added to an 0.5 ~ 5.0 cm column containing 100-200 mesh Bio-Rex 5~, chloride form (Bio-Rad~), wetted with distilled water, as described by Alberts et al.
~J. Proc. Natl. Acad. Sci. U.S.A., 1980, 77, 3967]. The unreacted [14C]HMG-CoA was absorbed on the resin and the [14C]mevalonolactone was eluted with distilled water (2 ~ 1 ml) directly into 7-ml scintillation vials. Five milliliters of Aquasol-2 (New England Nuclear) was added to each vial, and radioactivity was measured in a Packard Tri Carb Prias scintillation counter. IC50 values were determined by plotting percentage inhibition against test compound concentration and fitting a straight line to the resulting data by using the least-squares method. For estimation of relative inhibitory potencies, compactin was assigned a value of 100 and the IC50 value of the test compound was compared with that of compactin determined simultaneously.
Representative of the intrinsic HMG-CoA
reductase inhibitory activities of the claimed compounds are the relative potencies tabulated below for a number of the claimed compounds.
13~0~52 TABLE
Relative Compounds of the Formula (II) Potency AS* R R1 S CO2H sec-butyl 26 R CH2OH sec-butyl 47 Relative to compactin arbitrarily assigned a value of 100 *AS = absolute stereochemistry of the methine moiety to which R is appended.
Included within the scope of this invention is the method of treating arteriosclerosis, familial hyper-cholesterolemia or hyperlipidemia which comprises administering to a subject in need of such treatment a nontoxic, therapeutically-effective amount of the compounds of formula (I) or (II) or pharmaceutical compositions thereof.
Also included within the scope of this invention is use of a compound of formula (I) or (II), or a pharmaceutically acceptable salt thereof, as an anti-hypercholesterolemic agent or as an HMG-CoA reductase inhibitor.
There is also included within the scope of this invention a compound of formula (I) or (II), or a pharmaceutically acceptable salt thereof, for use in the treatment of atherosclerosis and coronary heart disease.
The following examples illustrate the preparation of the compounds of the formulae(I) and (II) and related compounds and as such are not to be considered as limiting the invention set forth in the claims appended hereto.
. .
I34~32 The following media are utilized in the bioconversion reactions described below:
Medium A Grams per liter distilled water Yeast extract 4.0 Malt extract 10.0 Nutrient broth 4.0 Dextrose 4.0 pH 7.4 Medium sterilized for 20 min. at 121~C
Medium B Grams ~er liter distilled water Dextrose 10.0 Polypeptone 2.0 Meat extract 1.0 Corn steep liquor 3.0 pH 7.0 Medium sterilized for 20 min. at 121~C
I. Culture Conditions and Bioconversion A lyophilized tube of Nocardia autotrophica subsp. canberrica ATCC 35204 (MA-6180) was used to inoculate 18 x 175 agar slants (Medium A) which were incubated at 27~C for 7 days. The slant culture was washed with 5 ml of sterile medium B and transferred to a 250 ml flask containing 50 ml of sterile medium ~. This first stage seed was grown at 27~C on a 220 rpm shaker and, after 24 hours, 2 ml was transferred to another flask of sterile medium B.
Grown under the above conditions, the second seed was used to start the bioconversion culture: 20 ml of the seed culture was placed in 400 ml of sterile medium B in a 2L flask.
After the culture had grown for 24 hours, 80 mg of the sodium salt of 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(5)-(2,2-dimethyl-butyryloxy)-l(S)-naphthyl]-3(R),5(R)-dihydroxy-heptanoic acid was added to each flask. The incubation was continued for 28 hours or until no 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(5)-(2,2-dimethylbutyryloxy)-l(S)-naphthyl]-~(R),5(R)-dihydroxyheptanoic acid could be detected by HPLC. The whole broth was clarified by centrifugation followed by filtration through Whatman No. 2 filter paper.
II. HPLC Methods Aliquots of whole broth could be analyzed for 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethylbutyryloxy)-l(S)-naphthyl]-~(R),5(R)-dihydroxyheptanoic acid derivatives by HPLC. Filtered broth could be injected directly (10 to 20 ~1) or after dilution with methanol. The compounds were separated on reversed phase columns utilizing a gradient of " 1310~2 ~
35 to 45 percent aqueous acetonitrile at flow rates ranging between 1 and 3 ml/min. Addition of glacial acetic acid or H3PO4 (0.1 ml/L
mobile phase) was required for the separation of the free acids. Derivatives of 7-~1,2,6,7,8,8a(R)-he~ahydro-2(5),6(R)-dimethyl-8(5)-t2,2-dimethylbutyryloxy)-l(S)-naphthyl]-3-(R),5(R)-dihydroxyheptanoic acid were detected by monitoring the absorbance at 238 nm, as well as the absorbance ratio of 238 nm/228 nm. The Waters HPLC system included a WISP auto-injector, model 710B equipped with models 510 and 590 pumps, a model 490 UV-visible detector, and the 840 data system. A number of columns were used successfully for the separations, including the following: Waters ~
Bondapak-C18~, Altex Ultrasphere-C18~, Rainin Microsorb-C18~ and a Brownlee MPLC-C8~.
III. Methyl 7-rl,2,6,7,8,8a(R)-hexahydro-6(S)-hydroxymethyl-2(S)-methyl-8(S)-(2,2-dimethyl-- butyrylosy)-ltS)-naphthyl~-3(R),5(R)-dihydroxy-heptanoate. The whole broth of three X 400 ml culture broth was combined and filtered through Celite (TM) and ~a~man No. 2 (TM) filter paper. The filtrate was acidified to pH S.0 with 25 percent H3PO4 and then extracted with three, 700 ml-portions of ethyl acetate.
Following concentration under vacuum (25~C), the organic solution was extracted with four volumes of 0.1~ NaHCO3. The bicarbonate solution was slowly adjusted to pH 4.5 with H3PO4 and then extracted with two volumes .. . . ~_ ~ 13404~2 ethyl acetate which was subsequently concentrated to 100 ml in vacuo. The concentrate was combined with 150 ml of diethyl ether containing an excess of CH2N2 and stirred overnight for preparation of the methyl ester derivatives. Evaporation of the ether was performed under a stream of nitrogen and the remaining solution was washed with 100 ml of phosphate buffer, pH 7Ø The organic phase was taken to dryness in vacuo and the resulting residue was dissolved in a minimum of isopropanol. Final purification of methyl 7-tl,2,6,7,8,8a(R)-hexahydro-6(S)-hydroxymethyl-2(S)-methyl-8(S)-(2,2-dimethyl-butyryloxy)-l(S)-naphthyl]-3(R),5(R)-dihydroxyheptanoate was accomplished by HPLC
utilizing a Waters ~Bondapak-C18 column (1 x 30 cm). The mobile phase was 34 percent aqueous CH3CN at 4 ml/min. Methyl 7-[1,2,6,7,8,8a(R)-hexahydro-6(S)-hydroxymethyl-2(S)-methyl-8(S)-(2,2-dimethylbutyryloxy)-l(S)-naphthyl]-3(R),5(R)-dihydroxyheptanoate had a retention time at 31 minutes. After evaporation of the solvent, the sample was dried under vacuum for 24 hours to afford the title compound which was identified by NMR.
lH nmr (CDC13) ~ 0.83 (3H, t, J=7Hz), 0.89 (3H, d, J=7Hz), 1.107 (3H, s), 1.111 (3H, s), 2.16 (H, m), 3.51 (H, d of d, J=5.5, 10.5 Hz), 3.61 (H, d of d, J=5.5, 10.5 Hz), 3.69 (3H,s), 3.77 (H, m), 4.22 (H, m) 5.36 (H, bs), 5.50 (H, bs), 5.80 (H, d of d, 6, 9.5 Hz), 6.00 (H, d, J-9.5 Hz).
- 13~0~2 IV. Isolation of 6(R)-[2-r8(S)-(2,2-Dimethyl-butyryloxy)-6(R)-carboxy-2(5)-methyl-1,2,6,7,8,8a (R)-hexahydronaphthyl-l(S)~ethyl]-4(R)-hydro~y-3,4,5,6-tetrahydro-2H-pyran-2-one and 6(R)-[2-[8(5)-(2,2-Dimethylbutyryloxy)-6(5)-carboxy-2(S)-methyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-l(S)]-ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one.
The whole broth (1200 ml) was clarified as before and then adjusted to pH 3.5 with H3PO4. The filtrate was loaded on a HP-20 column (3 x 50 cm) which had been equilibrated with water containing 0.1 percent CH3COOH.
After washing the column with 1 L of water and 1 L of 25 percent CH3CN, the products were eluted with 600 ml of 50 percent CH3CN. The acetonitrile was removed under vacuum at 35~C.
The water was taken to pH 8.0 with NaOH and washed with two 500 ml portions of CH2C12 which was discarded. After readjusting the pH
to 3.5 with H3PO4, the derivatives were first extracted into 1.8 L ethyl acetate and then back-extracted into 1 L of 1 percent NaHCO3. The bicarbonate solution was acidified to pH 5 with acetic acid and loaded on a HP-20 column (1.5 x 50 cm). Once the column was washed with 700 ml of H2O followed by 700 ml of 30 percent CH3CN, the column was eluted with a gradient of 30 to 50 percent CH3CN. The fractions were monitored by UV
absorbance (228, 238, 248 nm) and by HPLC.
Crude 6(R)-[2-[8(S)-(2,2-dimethylbutyryloxy)-..,~
~ . . .
~- 13404~2 6(S)-carbo~y-2(S)-methyl-1,2,6,7,8,8a(R)-hexa-hydronaphthyl-l(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one was collected at about 40 percent CH3CN.
After removing the solvent in vacuo, the resulting residue was sonicated with 20 ml of toluene for 10 minutes, 3 ~1 of CF3COOH was added and the mixture was heated for 30 minutes at 70~C. The-toluene was removed under vacuum at 70~C and the resulting residue was dissolved in 300 ~1 of CH3CN. The preceding procedure was employed to convert the derivative of 7-[1,2,6,7,8,8a(R)-hexa-hydro-2(S),6(R)-dimethyl-(2,2-dimethylbutyrylo~y)-l(S)-naphthyl]-3(R),5(R)-dihydro~yheptanoic acid to its lactone form for ease of isolation. Final purification was accomplished by HPLC using an Alte~-C8 column (1 ~ 25 cm) and a gradient of CH3CN/CH3OH/H2O/CH3COOH (20/30i50/0.01 to 25/30/45/0.01) at 2.7 ml/min. 6(R)-[2-[8(S)-(2,2-Dimethylbutyryloxy)-6(S)-carboxy-2(S)-methyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-l(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one had a retention time of 30 to 31 minutes and was identified by NMR. lH nmr (CDC13) ~ 0.82 (3H, t, J-7.5Hz), 0.88 (3H, d, J-7Hz), 1.11 (6H, s), 1.53 (H, m), 2.60 (H, m) 2.72 (H, d of d, J=5, 18Hz), 3.29 (H, m), 4.365 (H, m), 4.60 (H, m), 5.39 (H, bs), 5.62 (H, bs), 5.83 (H, d of d, J-6, 10 Hz), 6.00 (H, d, J=10 Hz) An alternate final purification involved fractionation by preparative HPLC using a Vydac~ C-18 column and eluting with 0-60% CH3CN/0.170 1340i52 phosphoric acid. Application of this purification technique to a partially-purified mixture of acidic materials (200 mg) afforded fractions A containing a less polar, major component and fractions B
containing a more polar, minor component.
Concentration of fractions A in vacuo to remove the bulk of the CH3CN gave an aqueous mixture which was extracted with chloroform. The organic extract was washed with saturated brine, dried (Na2S04), filtered and evaporated in vacuo to provide 6(R)-[2-[8(S)-(2,2-dimethylbutyryloxy)-2(S)-methyl-6(5)-carboxy-1,2,6,7,8,8a(R)-hexanaphthyl-l(S)~ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one as a colorless solid, mp 167-170~C; H nmr (CD3CN) ~
6.04 (H, d, J=9.8 Hz), 5.88 (H, d of d, J=9.7,6.OHz), 5.62 (H, m), 5.33 (H, m), 4.56 (H, m), 4.23 (H, m), 3.23 (H, m), 2.62 (H, d of d, J=17.4, 4.8Hz), 2.44 (H, d of d of d, J=17.5,3.7, 1.6Hz), 1.12 (6H, s), o.go (3H, d, J=7.1Hz), 0.83 (3H, t, J=7.5Hz).
Recrystallization of this 6B-carboxy isomer from EtoAc-Hexane did not alter the mp. Furthermore, this 6B-carboxy isomer mp 167-170~ C, could be obtained directly from the partially-purified mixture of acidic materials (vida ~ ) by crystallization from di-n-butyl ether.
Anal. Calc'd for C25H3607: C, 66.94; H, 8.09.
Found: C, 66.66; H, 8.41.
From fractions B (vida su~ra) there was obtained the corresponding 6a-carboxy isomer 6(R)-~2-[8(S)-(2,2-dimethylbutyryloxy)-2-(S)-methyl-6(R)-carboxy-1,2,6,7,8,8a(R)-hexahydronaphthyl-l(S)]-ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one, as a colorless solid, mp 189-194~C; lH nmr (CD3CN) ~ 6.06 (H, d, J=9Hz), 5.88 (H, d of d, . ,.. ~ .... ~
13~0452 J=9.5, 5.9Hz), 5.71 (H, m), 5.24 (H,m), 4.51 (H, m), 4.21 (H, m), 3.20 (H, m), 2.70 (H, m), 2.62 (H, d of d, J=17.4, 4.8Hz), 2.44 (H, m), 1.06 (H, s), 1.03 (3H, s), 0.89 (3H, d, J=7.0Hz), 0.82 (3H, t, J=7.5Hz).
Anal Calc'd for C2sH36O~: C, 66.94; H, 8.09.
Found: C, 66.70; H. 8.38.
In a similar fashion Nocardia autotrophica subsp. canberrica ATCC 35203 (MA6181) was utilized in the bioconversion reaction with the sodium salt of 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2,2-dimethylbutyryloxy)-l(S)-naphthyl]-3(R),5(R)-di-hydroxyheptanoic acid to afford the desired products.
Additionally, the sodium salt of 7-[1,2,6,7,8,8a(R)-hexahydro-2(S),6(R)-dimethyl-8(S)-(2-methylbutyryloxy)-l(S)-naphthyl]-3(R), 5(R)-dihydroxyheptanoic acid, the sodium salt of ring opened mevinolin, was subjected to analogous bioconversion reactions utilizing both N. autotrophic subsp. ameth~stina ATCC 35204 (MA6180) and _ autotrophic subsp. canberrica ATCC 35203 (MA6181) to predominantly afford 6(R)-[2-[8(S)-(2-methylbutyryl-oxy)-6(S)-carboxy-2(S)-methyl-1,2,6,7,8,8a(R)-hexa-hydronaphthyl-l(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetra-hydro-2H-pyran-2-one of the invention and the methyl ester of 7-[1,2,6,7,8,8a(R)-hexahydro-6(S)-hydroxy-methyl-2(S)-methyl-8(S)-(2-methylbutyryloxy)-l(S)-naphthyl]-3(R),5(R)-dihydroxy-heptanoate of the invention, respectively.
. ~