Isolation and characterisation of irinans, androstane-type withanolides from Physalis peruviana L.

Annika Stein,Jakob Franke,Mark Brönstrup,Dave Compera,Bianka Karge

doi:10.3762/bjoc.15.196

Abstract

Withanolides are steroidal lactones widespread in Nightshade plants with often potent antiproliferative activities. Additionally, the structural diversity of this compound class holds much potential for the discovery of novel biological activity. Here, we report two newly characterised withanolides, named irinans, from Physalis peruviana with highly unusual truncated backbones that resemble mammalian androstane sex hormones. Based on biomimetic chemical reactions, we propose a model that links these compounds to withanolide biosynthesis. Irinans have potent antiproliferative activities, that are however lower than those of 4ß-hydroxywithanolide E. Our work establishes androwithanolides as a new subclass of withanolides.

Highlights

Traditional medicine has long been a source of inspiration for modern drug research
Several withanolides have been reported from P. peruviana and other Physalis species, most prominently physalins, perulactones and 4ß-hydroxywithanolide E (1) [5,6,7,8,9,10,11,12,13,14,15,16]
To isolate withanolides from P. peruviana, we used a purification strategy based on previous reports [17,18,19]

Summary

Introduction

An important example is Withania somnifera, known as ashwaghanda or Indian ginseng, which has been used in Ayurvedic medicine to treat a large variety of ailments [1]. Withanolides have been discovered in numerous genera other than Withania, for example Datura, Dunalis, Iochroma, Jaborosa, Lycium and Physalis [3], resulting in more than 300 known representatives [3]. Several withanolides have been reported from P. peruviana and other Physalis species, most prominently physalins, perulactones and 4ß-hydroxywithanolide E (1) [5,6,7,8,9,10,11,12,13,14,15,16].

Objectives

Results

Conclusion