11-hydroxymonocerin from the plant endophytic fungus Exserohilum rostratum

A new analogue of monocerin, 11-hydroxymonocerin (2), along with monocerin (1) and 12-hydroxymonocerin (3) were isolated from Cultures of Exserohilum rostratum, a fungal strain endophytic in Stemona sp. The structure of 2 was determined by analysis of NMR and MS data and by comparison of spectroscopic data to those of 1. Monocerin (1) and 11-hydroxymonoccrin (2) displayed activity against Plasmodium falciparum (K 1, multidrug-resistant strain) with IC50 values of 0.68 and 7.70 mu M, respectively. None of the compounds were cytotoxic against any of the tumor cell lines tested.