1991 Fiscal Year Final Research Report Summary

Study on The Structure-Sweetness Relationship of Dihydroflavonol Glycoside

Research Project

Project/Area Number	02670955
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Chemical pharmacy
Research Institution	Hiroshima University
Principal Investigator	KASAI Ryoji Hiroshima University School of Medicine Associate Professor, 医学部, 助教授 (10034018)
Project Period (FY)	1990 – 1991
Keywords	Leaves of Engelhardtia crysolepis / Dihydroflavonol glycoside / Sweet glycoside / Taxifolin glycoside / Neoastilbin
Research Abstract	The leaves of Engelhardtia crysolepis Hance (Juglandaceae) have been used as a sweet tea called huang-qi in China. Present author reported on the isolation of neoastillbin (3-O-rhamnosyl-(2S, 3S)-taxifolin, 1) as a sweet principle of the leaves together with three non-sweet isomers of neoastilbin, astilbin, neoisoastillbin and isoastilbin. In further investigation of the sweet principle of the leaves, an additional new sweet dihydroflavonol glycoside [glucosyl-rhamnosyl-(2R, 3R)-taxifolin, 2] was isolated. This report deals with the structural elucidation of 2, and isomerization of astilbin and 2. Furthermore, the isolation and identification of the flavonoid compound of four other Engelhardtia species, which grows in Yunan, China, were reported.