Practical Synthesis of Novel Citryl Glycoside, the Component of the Rhizomes of Gastrodia elata

摘要

The rhizome of Gastrodia elata Blume (Gastrodiae Rhizoma, Orchidaceae) has been used in traditional medicine as an anticonvulsant and sedatives in Korea, Japan and China. Identification of its constituents has focused mainly on phenolic compounds: besides a major phenolic glucoside (gastrodin [4-(β-D-glucopyranosyloxy)benzyl alcohol]), more than 15 phenolics have been isolated. Among them, tris[(4-β-D-glucopyranosyloxy)benzyl] citrate (parishin), 1,2-bis[(4-(β-D-glucopyranosyl-oxy)benzyl] citrate (parishin B) and 1,3-bis[(4-(β-D-glucopyranosyl-oxy) benzyl] citrate (parishin C) contain a citrate moiety, further, 1,5-dimethyl-citrate was also reported. Recently, we isolated a citrate containing constituent from Gastrodiae Rhizoma, and characterized its structure as trimethylcitryl-β-D-galacto-pyranoside. This new natural citrate glycoside shows an inhibitory activity on GABA transaminase, suggesting an anticonvulsive effect.