title: Milbemycins, a new family of macrolide antibiotics. Fermentation, isolation and physico-chemical properties of milbemycins D, E, F, G, and H.
abstract: Strain Au-3, a mutant of Streptomyces hygroscopicus subsp. aureolacrimosus, obtained with ultraviolet irradiation, was a high-yield strain of milbemycins D, E, F, G and H. Fermentation studies on the strains were conducted in shake flasks and 30-liter jar fermentors. Isolation of the metabolites was performed by adsorption on resinous adsorbent followed by elution with aqueous MeOH and separated by silica gel column chromatography. Milbemycin D was obtained as colorless needles after recrystallization and milbemycins E, F, G and H were purified to homogeneity by column chromatography. Physico-chemical characterization revealed that milbemycins D, E, F, G and H were new antibiotics possessing the 16-membered macrocyclic lactone with a 6,6-membered spiroketal ring system.
mesh_terms: D000900:Anti-Bacterial Agents; D055598:Chemical Phenomena; D002621:Chemistry; D005285:Fermentation; D007783:Lactones / Q000302:isolation & purification / Q000378:metabolism; D018942:Macrolides; D013302:Streptomyces / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D007783:Lactones; D018942:Macrolides; C027837:moxidectin