3,4-Seco-spirostane sapogenins with cytotoxic activity from Allium umbilicatum boiss

Abstract

Two new sapogenins, named seco-umbilicagenins A and B (1 and 2), possessing a new chemical structure based on a 3,4-seco-spirostane skeleton, were isolated from Allium umbilicatum Boiss. The chemical structures of seco-umbilicagenins A and B were established through a combination of extensive spectroscopic analysis, mainly nuclear magnetic resonance spectroscopy and mass spectrometry, and chemical methods as (2S, 25R)-2,5 alpha, 6 beta-trihydroxy-3,4-seco-spirosta-3,4-dioic acid (1) and (2S, 25R)-2,4,5 alpha-trihydroxy-6-oxo-3,4-seco-spirostan-3-oic acid (2). Interestingly, the isolated compounds exhibited cytotoxic activity on J-774, murine monocyte/macrophage, and WEHI-164, murine fibrosarcoma, cell lines. To the best of our knowledge this is the first time that 3,4-seco-spirostane sapogenins are isolated from natural sources, being this skeleton obtained by synthetic modification of intact sapogenins. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.