The Isolation and Structural Elucidation of Three New Neolignans, Puberulins A, B, and C, as Platelet Activating Factor Receptor Antagonists for Piper puberulum

Three new neolignans, piperulins [corrected] A [1], B [2], and C [3], were isolated from Piper puberulum. Their structures and relative stereochemistries were determined from spectral data and the X-ray crystallographic analysis of 1. Compounds 1 and 3 inhibit specific platelet activating factor receptor binding with IC50 values of 7.3 and 5.7 microM, respectively.