Holophyllane A: A Triterpenoid Possessing an Unprecedented B-nor-3,4-seco-17,14-friedo-lanostane Architecture from Abies holophylla

Abstract

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 mechanicsbased 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.