Two cytotoxic 6,7-seco-spiro-lacton-ent-kauranoids from Isodon rubescens

Abstract

The present study was performed to investigate the chemical components of the branches and leaves of Isodon rubescens. Two 6,7-seco-spiro-lacton-ent-kauranoids were obtained. Based on the extensive spectroscopic analyses, their structures were elucidated as 6-epi-11-O-acetylangustifolin (1) and 11-O-acetylangustifolin (2), respectively. The structure of 2 was further comfirmed by X-ray crystallography analysis. MTT method was employed to evaluate their cytotoxity against human lung cancer cell lines A549 and leukemia cell lines K562.

Keywords:

• Isodon
• Isodon rubescens
• ent-kauranoids
• cytotoxity
• 6,7-seco-spiro-lactone

Acknowledgments

The authors are grateful to Professor Juan Yang, Center for Pharmacology and Drug Screening, The Key Laboratory of Chemistry for Natural Products, Guizhou Province and Chinese Academy of Sciences, for the experiments of cytotoxicity against human lung cancer cell lines A549 and leukemia cell lines K562.