Platelet activating factor (PAF) is a highly potent endogenous phospholipid mediator, involved in various inflammatory and cardiovascular disorders. As part of a research program dealing with PAF inhibitors isolated from Piper plant species, we have isolated kadsurenone (I), denudatin B (II), and
Two new neolignans, piperkadsin A (1) and piperkadsin B (2), as well as 11 known neolignans, three known alkaloids, the highly oxygenated compound (+)-crotepoxide, and stigmasterol were isolated from the stems of Piper kadsura. The anti-inflammatory activities of these compounds were evaluated.