Benzamides and quinazolines from a mangrove actinomycetes Streptomyces sp. (no. 061316) and their inhibiting caspase-3 catalytic activity in vitro

Abstract

One new benzamide, 3-hydroxyl-2-N-iso-butyryl-anthranilamide (1), together with two known benzamides (2, 3) and three known quinazolines (4-6), was isolated from a mangrove actinomycetes Streptomyces sp. (No. 061316), which displayed inhibiting Caspase-3 activity in vitro. The structure of 1 was elucidated by electrospray ionization (ESI)-MS, NMR spectroscopies and X-ray crystal diffraction. After evaluation of all compounds for their inhibitory effect on Caspase-3 in vitro, 3-hydroxyl-anthranilamide (2) and 8-hydroxyl-2,4-dioxoquinazoline (6) showed activity against Caspase-3 with IC50 values of 32 and 36mM, respectively. © 2011 Pharmaceutical Society of Japan.