Assignment of Absolute Configuration of a New Hepatoprotective Schiartane-Type Nortriterpenoid Using X-Ray Diffraction.

Xiaojuan Wang,Daneel Ferreira,Shuai Li,Mark Hamann,Jiabao Liu,Jiabao Chen,Frank Fronczek

doi:10.3390/molecules22010065

Abstract

A new schiartane-type nortriterpenoid, micrandilactone H was isolated from Kadsura longipedunculata Finet et Gagnep. Its 2D (two dimension) structure was elucidated by NMR spectroscopic analysis, and it is similar to that of Kadnanolactones H and the absolute configuration was established through X-ray diffraction and ECD data analysis. This represents the first complete assignment of the absolute configuration of a schiartane-type nortriterpenoid by X-ray diffraction and the ECD method. Micrandilactone H showed moderate hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced toxicity in HepG2 cells with cell survival rates of 56.84% at 10 μM.

Highlights

The roots and stems of plants of the genus Kadsura, have been used in traditional Chinese medicines (TCM) to treat blood disease, remove stasis and relieve pain
Phytochemical studies showed that the principal bioactive constituents of the genus Kadsura are lignans and triterpenoids
C, except for an extra is a schiartane-type nortriterpenoid whose structure is similar to micrandilactone C, except for an double bond, bond, one less groupgroup and the different location of theofC-18 groupgroup

Summary

Introduction

The roots and stems of plants of the genus Kadsura, have been used in traditional Chinese medicines (TCM) to treat blood disease, remove stasis and relieve pain. Nortriterpenoids are a structurally intriguing group of highly oxygenated, polycyclic, fused heterocyclic natural products produced by the plants of the genera Schisandra and Kadsura. Some of these compounds showed promising anti-HIV (human immunodeficiency virus) bioactivities. The C29 type is the most common and can be divided into five classes including schiartane, 18(13→14)-abeo-schiartane, schisanartane, preschisanartane and wuweiziartane [1] Their planar structures and relative configurations have been successfully elucidated by modern NMR techniques.

Results

General Experimental Procedures

Plant Material

Extraction and Isolation

X-ray Crystallographic Analysis of Micrandilactone H