Benadrostin

Benadrostin, a new inhibitor of poly(ADP-ribose) synthetase, has been isolated from the culture broth of Streptomyces flavovirens MH499-O'F1. The structure of benadrostin was defined as 8-hydroxy-2H-1,3-benzoxazine-2,4-dione by an analysis of spectral properties and chemical studies of benadrostin and its derivatives.

Six compounds were isolated as radical scavengers from the culture broth of a marine-derived actinomycete strain USF-TC31. The structures of two novel compounds were determined to be those of N-carbamoyl-2,3-dihydroxybenzamide (5) and 2-acetamido-3-(2,3-dihydroxybenzoylthio)propanoic acid (6), and four known compounds were identified to be anthranilic acid (1), 2,3-dihydroxybenzoic acid (2), 2,3-dihydroxybenzamide (3) and benadrostin (4) on the basis of spectroscopic data. Compound 6 was characterized as a racemate by its specific rotation. Each of the obtained compounds was evaluated for DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, and compounds 2, 3, 5 and 6 each exhibited potent activity in comparison with the butylhydroxytoluene (BHT) positive control.

Benadrostin, a new inhibitor of poly(ADP-ribose) synthetase was discovered in the fermentation broth of Streptomyces flavovirens MH499-O'F1. It was purified by chromatography followed by solvent extraction and then isolated as colorless prisms. Benadrostin has the molecular formula of C8H5NO4. It was competitive with the substrate, and the inhibition constant (Ki) was 34 microM.