Holophyllane A: A Triterpenoid Possessing an Unprecedented B-nor-34-seco-1714-friedo-lanostane Architecture from Abies holophylla

摘要

A novel triterpenoid, holophyllane A (>1), featuring a B-nor-3,4-seco-17,14-friedo-lanostane, along with its putative precursor, compound >2 were isolated from the methanol extract of the trunks of Abies holophylla. The 2D structure and relative configuration of >1 were initially determined via analysis of 1D and 2D NMR spectroscopic data and the assignment was confirmed by quantum mechanics-based NMR chemical shift calculations. The absolute configuration was established by comparison of the experimental and simulated ECD data generated at different theory levels. Compounds >1 and >2 exhibited moderate to weak cytotoxicity and significant inhibitory activity against nitric oxide (NO) production.