Furostanol oligoglycosides from Asparagus cochinchinensis

Abstract

Three new furostanol oligoglycosides, named aspacochioside A (1), B (2) and C (3), together with the known compound 3-O-[{α-l-rhamnopyranosyl-(1→4)}{β-d-glucopyranosyl}]-26-O-[β-d-glucopyranosyl]-(25S)-5β-spirostane-3β-ol were isolated from the roots of Asparagus cochinchinensis. Their structures were elucidated by spectroscopic techniques (IR, HR-ESIMS, ESIMS/MS, 1D and 2D NMR) and chemical methods as 3-O-[{α-l-rhamnopyranosyl-(1→4)}{β-d-glucopyranosyl}]-26-O-[β-d-glucopyranosyl]-(25S)-5β-furostane-3β,22α,26-triol (1), 3-O-[{α-l-rhamnopyranosyl-(1→4)}{β-d-glucopyranosyl}]-26-O-[β-d-glucopyranosyl]-22α-methoxy-(25S)-5β-furostane-3β,26-diol (2), and 3-O-[{α-l-rhamnopyranosyl-(1→4)}{β-d-glucopyranosyl}]-26-O-[β-d-glucopyranosyl]-(25S)-5β-furost-20(22)-en-3β,26-diol (3).

Keywords:

• Furostanol oligoglycosides
• Aspacochiosides A–C

Acknowledgements

The authors are grateful to Professor A. Zeper for mass spectra measurements. We also thank Mr W.-Y. He for his assistance in obtaining the 2D NMR spectra. This work was supported by the Ministry of Science and Technology of China, grant No. 99-929-01-26.