[A new benzamide derivative from rice fermentation of Streptomyces sp. CPCC 202950]

Eight compounds were isolated from the rice fermentation of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over silica, Sephadex LH-20, flash C₁₈, and reversed-phase HPLC. Their structures were identified as 3-[(3'-amino-3'-oxoprop-1'-en-2'-yl)oxy]benzamide (1), m-hydroxybenzamide (2), leptosphaepin (3), 5-methyluracil (4), feruloylamide (5), p-hydroxyphenylacetoamide (6), vanillamide (7), cyclo (L-val-L-ala) (8). Among them, 1 was a new benzamide analogue, and 2 was a new natural product. In the preliminary assays, none of the compounds 1-8 exhibited obvious inhibition of HIV-1 protease activity, and toxic with the Hela, HepG2, and U2OS cells. (IC₅₀ > 10 μmol•L⁻¹).