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|Title:||Biosynthesis of Selected Antibiotics|
|Author(s):||Snyder, William Chapin|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||The biosynthetic pathway for the novel antibiotics nodusmicin (9) and nargenicin (10) was established as polyketide in origin. Three metabolites previously unreported from Nocardia argetinensis var. Huang (ATCC 31306) were isolated and identified as 18-O-acetylnodusmicin (13), and 18-O-acetylnargenicin (14).
In biosynthetic studies of the paulomycins (15, 16), a novel hydrazine, 1-succinyl-1,2-diazacycloheptane (18), was isolated. The paulomycins were found to be biosynthetically formed from a amino-acid side chain esterified to a pyruvate-derived C2 unit. This C2-unit is attached to one of two glucose-derived tetrahydropyran units, one of which contains a methoxy group derived from methionine. The isothiocyanate containing ester side chain is derived from acetate. Precursors for the hydrated quinone were not found.
In biosynthetic studies of geldanamycin (19), an idiotroph of 3-amino-5-hydroxybenzoic acid was prepared in addition to a mutant with improved production capabilities for geldanamycin. From this mutant, geldanamycin hydroquinone, azalomycin B(20), nigericin (21), guanidylfungin A (22), and abierixin (23) were isolated.
In studies with an idiotroph of a novobiocin producing organism, 3-(4-hydroxy-3-isopentenylbenzamido)-4,7-dihydroxyquinolin-2-one and 3-(4-acetoxy-3-isopentenylbenzamido)-4,7-dihydroxythiocoumarin were fed in mutasynthetic experiments. Neither the nitrogen nor the sulfur analogue of the coumarin ring was incorporated although the sulfur-containing analogue was deacetylated.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987.
|Date Available in IDEALS:||2014-12-15|