Two new metabolites of a marine endophytic fungus (No. 1893) from an estuarine mangrove on the South China Sea coast

The endophytic fungus No. 1893 was isolated from the dropper of Kandelia candel from an estuarine mangrove on the South China Sea coast. The ethyl acetate extract of the fermentation broth of this fungus strain exhibited cytotoxicity toward NCI4460 and Bel-7402, and high activities against Heliothis armigera (Hühner) and Sinergasilus spp. Two new lactones, 1893A () and B (), together with 5-(p-hydroxybenzyl)hydantoin and two cyclodipeptides, cyclo-(Ser-Leu) and cyclo-(Phe-Gly), were isolated from the extract. Their structures were determined by spectroscopic experiments, including X-ray diffraction.