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

Abstract: Zaragozic acids isolated from a culture of MF5465 have been subjected to photoreaction, then derivatized at the 4-keto position. The resulting derivatives are active as squalene synthetase inhibitors and are useful in the treatment of hypercholesterolemia.

Abstract: This invention relates to compounds of structural formula ##STR1## which are inhibitors of squalene synthase and useful as cholesterol lowering agents.

Abstract: Described is a process for producing a new FK-506 antagonist agent, a C-21 hydroxylated analog of FR-900520 under novel fermentation conditions utilizing the novel microorganism, Streptomyces hygroscopicus (Merck Culture Collection MA 6832) ATCC No. 55166. The macrolide antagonist is useful in preventing and/or counteracting accidental or inadvertent FK-506 overdosage in an FK-506 therapeutic program designed to prevent autoimmune diseases or human host rejection of foreign organ transplants, e.g. bone marrow, liver, lung, kidney and heart transplants.

Abstract: A dipeptide isostere is the biotransformed product after incubation with a culture of Streptomyces. It inhibits HIV protease, and is 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. Methods of treating AIDS and methods of preventing or treating infection by HIV are also described.

Abstract: A novel dipeptide isostere is the biotransformed product after incubation with a culture of Streptomyces. It inhibits HIV protease, and is 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. Methods of treating AIDS and methods of preventing or treating infection by HIV are also described.

Abstract: A process for the lactonization of mevinic acid HMG-CoA reductase inhibitors and analogs thereof is disclosed.

Abstract: Novel 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors which are useful as antihypercholesterolemic agents are represented by the following structural formulae (I) and (II): ##STR1## are disclosed.

Abstract: Non-ionic, lipophilic substances are isolated from aqueous or aqueous-organic solution by treatment with a macroreticular polymeric absorbent followed by elution with additional or a different organic solvent.

Abstract: Fermentation broths or impure solutions containing thienamycin, a substance having antibiotic activity against gram-negative and gram-positive microorganisms, are purified using a sequence of ion exchange resins, starting with an anion exchange resin of the polystyrene-trimethylammonium type in the HCO.sub.3 -cycle, and ending with absorption on and elution from a polymeric cross-linked polystyrene-type resin adsorbent. Variations in the intermediate steps, e.g. different resins and eluates are possible and are illustrated within.