The calanolides, a novel HIV-inhibitory class of coumarin derivatives from the tropical rainforest tree, Calophyllum lanigerum - Kashman, Y; Gustafson, KR; Fuller, RW; Cardellina, JH; McMahon, JB; Currens, MJ; Buckheit, RW; Hughes, SH (J Med Chem, 1992)