α-Glucosidase Inhibition Activity by Cyclic Diarylheptanoids from Alnus sieboldiana

Abstract

A diarylheptanoid, named 3,17-dihydroxy-tricyclo[12.3.1.1^2,6]nonadeca- 1(18),2,4,6(19),14,16-hexaen-9,11-dione, was newly isolated from the branch wood of Alnus sieboldiana, together with two known diarylheptanoids. The chemical structure of this compound was assigned on the basis of the NMR and MS data, information obtained though 1D- and 2D-NMR analyses. These three diarylheptanoids were found to significantly inhibit the activity of α-glucosidase.

Keywords:

• Alnus sieboldiana
• Betulaceae
• cyclic diarylheptanoids
• α-glucosidase inhibition activity

Acknowledgments

This research was supported in part by a Grant-in-Aid for Scientific Research (No. 23380098) from the Ministry of Education, Culture, Sports, Science and Technology in Japan.

The authors wish to thank Yasuo Yuasa, former teaching staff, Shizuoka University Forest, for plant identification and Akihito Yagi, Technical Support Division, Faculty of Agriculture, Shizuoka University, for assistance with NMR analyses.