Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded 11 new compounds including cytosporones J-N (1-3, 5-6), five new coumarins pestalasins A-E (8-12), and a new alkaloid named pestalotiopsoid A (14), along with the known compounds cytosporone C (4), dothiorelone B (7), and 3-hydroxymethyl-6,8-dimethoxycoumarin (13). The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis.