Asunto(s)
Antibacterianos/química , Eritromicina/análogos & derivados , Saccharopolyspora/genética , Saccharopolyspora/metabolismo , Antibacterianos/biosíntesis , Eritromicina/biosíntesis , Eritromicina/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Conformación MolecularRESUMEN
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.
Asunto(s)
Antihelmínticos/metabolismo , Ivermectina/análogos & derivados , Streptomyces/metabolismo , Animales , Antihelmínticos/química , Antihelmínticos/farmacología , Caenorhabditis/efectos de los fármacos , Ácidos Carboxílicos/metabolismo , Cromatografía Líquida de Alta Presión , Dípteros , Fermentación , Ivermectina/química , Ivermectina/metabolismo , Ivermectina/farmacología , Estructura Molecular , Mutación , Streptomyces/genéticaRESUMEN
UK-63,052 complex, a new group of quinomycin-like antibiotics comprising UK-63,052 (factor A), UK-63,598 (factor C), UK-65,662 (factor B) and several uncharacterised minor components, is produced by a new subspecies of the genus Streptomyces for which the name Streptomyces braegensis Dietz subsp. japonicus, is proposed. The strain, N617-29, is characterised by a negative melanin reaction, grey aerial mycelium, spiral spore chains and smooth or slightly warty spores. Structure determination has identified UK-63,052, C56H68N10O14S2, UK-63,598, C53H62N10O14S2 and UK-65,662, C55H66N10O14S2 as quinaldic acid substituted quinomycins with unusual bridgehead sulfur substitution as shown in Fig. 3.