New cineromycins and musacins obtained by metabolite pattern analysis of Streptomyces griseoviridis (FH-S 1832). II. Structure elucidation.

A detailed analysis of the secondary metabolite pattern produced by Streptomyces griseoviridis (strain FH-S 1832) using a chemical screening method resulted in the detection, isolation and structure elucidation of new 14-membered lactones of the cineromycin B-type [dehydrocineromycin B (5), oxycineromycin B (7), and 2,3-dihydrocineromycin B (8)], as well as new gamma-lactones related to nigrosporalactone and 4,5-dihydroxy-octa-2,6-dienoic acid esters named musacins A to F (10, 13 approximately 15, 17, 18 and 21). The constitution of these metabolites were deduced from spectroscopic data as well as chemical transformations. The configuration of musacin D (10) was determined by derivatization with chiral acids (Helmchen's method).

Metabolic products of microorganisms. 239. Bacimethrin isolated from Streptomyces albus identification, derivatives, synthesis and biological properties.

Bacimethrin (1), known as a thiamine antagonist produced by Bacillus megatherium, was isolated from Streptomyces albus and has been further characterized by NMR spectra and acetylation. A new easy three step synthesis for 1 is described. The biological activity of 1, and its mode of action were discussed. There are indications that bacimethrin inhibits the phosphorylation of 4-amino-5-hydroxymethyl-2-methylpyrimidine (Pyr-OH) during thiamine biosynthesis.

Secondary metabolites by chemical screening. I. Calcium 3-hydroxyquinoline-2-carboxylate from a Streptomyces.

Streptomyces griseoflavus subsp. (Gö 3592) was investigated by chemical screening methods. The mycelium contained gilvocarcin V (1). The culture filtrate contained the calcium salt of 3-hydroxyquinoline-2-carboxylic acid (2) confirmed by spectroscopic methods and by a 5-step partial synthesis of the free acid (3).