Two new diterpenoids from the endophytic fungus Trichoderma sp Xy24 isolated from mangrove plant Xylocarpus granatum

Two new harziane diterpenoids, named (9R,10R)-dihydro-harzianone (1) and harzianelactone (2), were isolated from the endophytic fungus Trichoderrna sp. Xy24 by using various column chromatography techniques. Their structures were determined on the basis of extensive spectroscopic (HR-ESI-MS, 1D NMR, 2D NMR and CD) analyses. Among them, 1 was the reductive product of harzianone and 2 was the Baeyer-Villiger monooxygenase catalyzed oxidation product of harzianone. Compound 1 exhibited cytotoxic activity against HeLa and MCF-7 cell lines with IC50 values of 30.1 mu mol/L and 30.7 mu mol/L, respectively. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.