Abstract: Biotransformation products of a fermentation with culture MA7074 are potent HIV protease inhibitors. These products are useful in the prevention or treatment of infection by HIV and in the treatment of AIDS, either as compounds, pharmaceutically acceptable salts, pharmaceutical composition ingredients, whether or not in combination with other antivirals, immunomodulators, antibiotics or vaccines. Methods of treating AIDS and methods of preventing or treating infection by HIV are also described.

Abstract: The present invention provides a process for the stereoselective reduction of phenylalkyl ketones to their corresponding (S)-hydroxy compounds. The process utilizes the novel microorganism Microbacterium MB 5614 to effectuate the chiral reduction. The present invention also provides said novel Microbacterium, which has been deposited with the ATCC and assigned the accession number ATCC 55557.

Abstract: A compound of structural formula ##STR1## having antihypercholesterolemic utility is produced by culturing a Streptomyces sp.

Abstract: A process for reducing a phenylalkyl ketone to the corresponding (S)-hydroxy derivative is disclosed. The process comprises contacting the phenylalkyl ketone with Mucor hiemalis IFO 5834 and recovering the (S)-hydroxy derivative.

Abstract: New cholesterol lowering compounds are formed from the photochemical treatment of the zaragozic acids.

Abstract: Microbial transformation of a macrolide immunosuppressant by the microorganism Streptomyces sp., (Merck Culture Collection MA 6960) ATCC No. 55387 yields a compound of the structural formula (I): ##STR1## This compound is an immunosuppressant useful in a mammalian host for the treatment of autoimmune diseases, infectious diseases, the prevention of rejection of foreign organ transplants and/or related afflictions, diseases and illnesses.

Abstract: Compounds of Structural Formula (I) ##STR1## are produced by directed biosynthesis. These compounds are squalene synthetase inhibitors and thus useful as cholesterol lowering agents, antifungal agents and cancer treatment agents.

Abstract: Compounds of Structural Formula (I) ##STR1## are produced by directed biosynthesis. These compounds are squalene synthase inhibitors and thus useful as cholesterol lowering agents and antifungal agents. These compounds are also inhibitors of farnesyl protein transferase and farnesylation of the oncogene protein Ras and thus useful in treating cancer.

Abstract: Described is a process for producing a new immunosuppressant, a C-19/C-22 cyclic hemiketal (Compound I) biotransformation analog of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces sp. (Merck Culture Collection MA6969) ATCC No. 55280. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: Described is a process for producing an immunosuppressant, "demethimmunomycin" (L-683,7411) a C-31 demethylated analog of L-683,590 under fermentation conditions utilizing the microorganism, Actinoplanacete sp, (Merck Culture Collection MA 6559) ATCC No. 53771. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow and heart transplants.

Abstract: Described is a process for producing a new immunosuppressant, a C-19/C-22 cyclic hemiketal (Compound I) biotransformation analog of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces sp. (Merck Culture Collection MA6971) ATCC No. 55282. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: Described is a process for producing a new immunosuppressant, a C-31 desmethyl, C-19/C-22 cyclic hemiketal biotransformation analog (Compound I) of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces, lavendulae ATCC No. 55209. Also disclosed is the C-31 methylated derivative (Compound II) of Compound I produced by enzymatic methylation using 31-O-desmethylimmunomycin O-methyl transferase, (DIMT), a methyl transferase enzyme. The macrolide immunosuppressants are useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: This invention relates to compounds of structural formula (I): ##STR1## which are squalene synthase inhibitors and thus useful as cholesterol lowering agents. The compounds also exhibit antifungal activity and are inhibitors of farnesyl-protein transferase.

Abstract: Described is a process for producing a new immunosuppressant, L-682,992, a C-13, C-31 demethylated ring-rearranged analog of L-679,934, under novel fermentation conditions utilizing the microorganism, Actinoplanacete Sp., (Merck Culture Collection MA 6559) ATCC No. 53771. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow and heart transplants.

Abstract: Described is a process for producing a new immunosuppressant, a C-19/C-22 cyclic hemiketal (Compound I) biotransformation analog of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces sp. (Merck Culture Collection MA6970) ATCC No. 55281. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: Described is a new immunosuppressant, L-683,519, a monodemethylated rearranged derivative of L-679,934, (FK-506) produced under fermentation conditions utilizing the microorganism, unidentified Actinomycete (Merck Culture Collection MA 6474) ATCC No. 53828. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow and heart transplants.

Abstract: Described is a process for producing a new immunosuppressant, a C-19/C-22 cyclic hemiketal (Compound I) biotransformation analog of FR-900520, under novel fermentation conditions utilizing the novel microorganism, Streptomyces sp. (Merck Culture Collection MA6968) ATCC No. 55279. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: Described is a new immunosuppressant, L-683,756, a bisdemethylated, ring rearranged derivative of L-683,590, produced under fermentation conditions utilizing the microorganism, Actinoplanacete sp. (Merck Culture Collection MA 6559) ATCC No. 53771. The macrolide immunosuppressant is useful in preventing human host rejection of foreign organ transplants, e.g. bone marrow and heart transplants.

Abstract: Incubation of 13.beta.-hydroxy ivermectin aglycone with a species of Bacillus subtilis or the incubation of 13-deoxy ivermectin aglycone with a mixed culture of a species of Bacillus subtilis and of Streptomyces griseus results in the production of 13-.beta. ivermectin monoglucopyranoside as the major product and of 5-.beta. ivermectin monoglucopyranoside as the minor product.

Abstract: Novel cytochalasins are the biotransformed products after incubation with a substrate in a culture of the microorganism Kibdelosporangium sp. (Merck Culture Collection MA 6559), ATCC No. 53771. The compounds of the present invention inhibit HIV protease and are useful in the prevention or treatment of infection by HIV and the treatment of AIDS, either as a compound, pharmaceutically acceptable salt, pharmaceutical composition ingredient, whether or not as a prodrug or as a combination with other antivirals, anti-infectives, immunomodulators, antibiotics or vaccines.