New Pyranocoumarins Isolated from Calophyllum lanigerum and Calophyllum teysmannii

Abstract
During a chemotaxonomic survey of Calophyllum extracts present in the National Cancer Institute's natural product repository, four new pyranocoumarins were isolated from extracts of C. lanigerum var. austrocoriaceum and C. teysmannii var. inophylloide (King.) P. F. Stevens (Clusiaceae). The structure elucidation and anti-HIV activity of calanolide E2 (4), cordatolide E (5), pseudocordatolide C (6), and calanolide F (9), along with a simple prenylated coumarin precursor (11), are described here.