New cyclopentenone derivatives from an endophytic Streptomyces sp. isolated from the mangrove plant Aegiceras comiculatum.

From the mangrove plant Aegiceras comiculatum collected in South China an endophytic Streptomyces sp. was isolated. Following cultivation in a seawater-based medium, four new cyclopentenone derivatives, namely (5R) 3-amino-5-hydroxy-5-vinyl-2-cyclopenten-1-one (1), (5R) 5-hydroxy-3-[(methoxycarbonyl)amino]-5-vinyl-2-cyclopenten-1-one (2), (5R) 5-hydroxy-3-[[2-(4-hydroxyphenyl)ethyl]amino]-5-vinyl-2-cyclopenten-l-one (3), and 3-isobutylpropanamide-2-cyclopenten-l-one (4), were obtained from the fermentation broth. Their structures were elucidated by extensive spectroscopic (UV, IR, ESIMS, and 2D NMR) data analyses.