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

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

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...

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...

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

The thiazorifamycins are derived from rifamycin S and cysteine; rifamycins P and Verde are formed by chemical reactions, while rifamycin Q synthesis involves obligatory enzymatic assistance. All antibiotics come from a common six-member precursor lacking C-1 of cysteine; the thiazin-2-one ring of rifamycin Verde retains both C-2 and C-3 of cysteine, while the thiazole ring of rifamycins P and Q...

Isolation and structure of a new ansamycin antibiotic kanglemycin A from a Nocardia.

CaCO3 0.5%) in a 20-liter jar fermentor and incubated at 28°C for 48 hours. The seed culture (10 liters) was transferred to 200 liters of a production medium (glucose 3%, yeast meal 1%, peanut meal 0.5%, peptone 0.2%, CaCO3 0.1%, pH 7.0) in a 300-liter fermentor and the fermentation was carried out at 28°C for 96 hours. The fermentation broth (200 liters) of kanglemycin producing strain was coo...