title: Novel avermectins produced by mutational biosynthesis.
abstract: Avermectins with a wide range of novel C-25 substituents have been prepared by feeding carboxylic acids or their biosynthetic precursors to a Streptomyces avermitilis mutant strain ATCC 53568. This organism lacks the ability to form isobutyric and S-2-methylbutyric acids from their 2-oxo acid precursors and thus is unable to produce natural avermectins unless supplied with these acids. The novel avermectins produced by mutational biosynthesis possess broad-spectrum antiparasitic activity.
authors.affiliation: Central Research Division, Pfizer Ltd., Kent, England.
authors.forename: C J
authors.initials: CJ
authors.lastname: Dutton
authors.forename: S P
authors.initials: SP
authors.lastname: Gibson
authors.forename: A C
authors.initials: AC
authors.lastname: Goudie
authors.forename: K S
authors.initials: KS
authors.lastname: Holdom
authors.forename: M S
authors.initials: MS
authors.lastname: Pacey
authors.forename: J C
authors.initials: JC
authors.lastname: Ruddock
authors.forename: J D
authors.initials: JD
authors.lastname: Bu'Lock
authors.forename: M K
authors.initials: MK
authors.lastname: Richards
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002107:Caenorhabditis / Q000187:drug effects; D002264:Carboxylic Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004175:Diptera; D005285:Fermentation; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D015394:Molecular Structure; D009154:Mutation; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D000871:Anthelmintics; D002264:Carboxylic Acids; D007559:Ivermectin; C019264:avermectin