Thiazorifamycins. III. Biosynthesis of rifamycins P, Q and verde, novel metabolites from a mutant of Nocardia mediterranea.

Rifamycin Z, a novel ansamycin from a mutant of Nocardia mediterranea.

An Australian isolate of Nocardia mediterranea producing rifamycin SV.

Since its first announcement by P. Sensi et at. in 19591}, the rifamycin complex has been extensively studied by a number of workers2). The type culture Nocardia mediterranea (Margalith et Beretta) Thiemann et at. 1969*, then known as Streptomyces mediterranei^ was isolated from a soil sample collected in France. Sugawara et al.l) culturing an isolate (4107 A2) from a Japanese soil sample, repo...

Early intermediates in the biosynthesis of ansamycins. III. Isolation and identification of further 8-deoxyansamycins of the rifamycin-type.

A number of minor compounds were isolated from fermentations of the protorifamycin I producing strain Nocardia mediterranei F 1/24(1,2)) and identified by means of chemical and spectroscopic methods. Two types of structures were identified: Type 1: modified protorifamycins (derived from protorifamycin I) Type 2: defective rifamycins (8-deoxyrifamycins).

Ansamycin biogenesis: studies on a novel rifamycin isolated from a mutant strain of Nocardia mediterranei.

A novel ansamycin, rifamycin W, was isolated from a mutant strain of Nocardia mediterranei. The metabolic origin of rifamycin W was studied by (13)C nuclear magnetic resonance spectroscopy. Examination of the proton-decoupled pulse and Fourier transform (13)C spectra of rifamycin W biogenetically enriched with [1-(13)C]-, [2-(13)C]-, and [3-(13)C]propionate and with [1-(13)C]acetate has reveale...

Study to the biosynthesis of the rifamycin-chromophore in Nocardia mediterranei.

Nocardia mediterranei produces the antibiotic rifamycin B, which belongs to the ansamycin group. The structure of rifamycin consists of the ansa chain and the chromophore. One part of this chromophore, the seven-carbon amino unit, which initiates ansa chain formation in ansamycins, has been identified as 3-amino-5-hydroxybenzoic acid. Kibby et al. 1] synthesized [carboxy-14C]3-amino-5hydroxyben...