Allahabadolactones A and B from the endophytic fungus, Aspergillus allahabadii BCC45335

Abstract

Two new compounds, allahabadolactones A (1) and B (2), along with 10 known compounds including 16-amino-isopimar-7-en-19-oic acid (3), 16-α-d-glucopyranosyloxyisopimar-7-en-19-oic acid (4), 16-α-d-mannopyranosyloxyisopimar-7-en-19-oic acid (5), ergosterol, (22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol, cerevisterol, (R)-(-)-methoxycarbonylmellein, (-)-piliformic acid, 7-dechlorogriseofulvin, and cytochalasin D, were isolated from the endophytic fungus, Aspergillus allahabadii BCC45335. Their chemical structures were determined based on NMR spectroscopic and mass spectrometric analyses. The absolute stereochemistry of compound 1 was established by an X-ray crystallographic analysis and the reactions with Mosher's reagents. A plausible biosynthesis of allahabadolactones A (1) and B (2) was also proposed. Antibacterial activity against Bacillus cereus and cytotoxicity against MCF-7, KB, NCI-H187, and Vero cells of the isolated compounds were also evaluated.