Two new 8-isopentenyl isoflavane derivatives from Astragalus dolichochaete diels

Abstract

Astragali Radix (Huangqi) is one of the well-known traditional Chinese medicines and has been used in China for more than two thousand years. As a close species, Astragalus dolichochaete Diels was found to possess cytotoxicity during our preliminary study of Astragalus plants from Yunnan Province, China. To better understand the chemical foundation of the cytotoxicity, the major constituents of A. dolichochaete were studied. As a result, two new 8-isopentenyl isoflavane derivatives, dolichochaeteins A and B (1 and 2), together with ten known constituents were isolated, and their structures were elucidated by means of spectroscopy, mainly 1D and 2D NMR techniques. The cytotoxic activities were evaluated for the raw extract, ethyl acetate fraction, compound 2 and glyasperin H (3) against human gastric carcinoma cell line SGC-7901, human hepatoma cell line SMMC-7721 and human leukemic cell line K562. All the samples exhibited significant cytotoxicity.

Graphical Abstract

Keywords:

• Astragalus dolichochaete
• Leguminosae
• isoflavanes
• flavanones
• structural elucidation
• cytotoxicity

Acknowledgements

The authors are grateful to Mr. Ling-Yun Jiang of The Library of Dali University for his kindly help with information retrieval. We thank Mr. Erich Grundel, a retired employee (Chemist) from FDA, USA, for manuscript revision.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was financially supported by the National Natural Science Foundation of China [grant numbers 31170313 and 81460532], and the Innovation Team Project of Dali University for Development and Utilization of Characteristic Medicinal Plants in Western Yunnan & Bai Nationality Medicines [grant number ZKLX2019106].