Novel Pentacyclic seco-Prezizaane-Type Sesquiterpenoids with Neurotrophic Properties from Illicium jiadifengpi

Abstract
Three novel seco-prezizaane-type sesquiterpenoids, jiadifenolide (1), jiadifenoxolane A (2), and jiadifenoxolane B (3), were isolated from the pericarps of Illicium jiadifengpi. Their pentacyclic cage structures were determined by 2D-NMR methods, chemical conversion, and single-crystal X-ray analysis. Compounds 1 and 2 strongly promote neurite outgrowth in primary cultured rat cortical neurons at concentrations ranging from 0.01 to 10 μM.