STUDIES ON THE CHEMICAL CONSTITUENTS OF RHYNCHOTECHUM VESTITUM HOOK. F. ET THOMS

Rhynchotechum vestitum Hook. F. et Thoms. mainly distributed in the southern part of Yunnan Province of China, has been used as a folk remedy for the treatment of hepatitis No information has been found in the literature about its chemical investigation. In this paper, five compounds isolated from the ethanol extract of the stem and root of the plant are reported. Four of them were identified as β-sitosterol (Ⅰ), lupeol (Ⅱ), rubiadin 1-methylether (Ⅲ) and rubiadin (Ⅳ). The fifth an orange needle crystal (C₁₇ H₁₄O₆, mp 236.5～238℃) is a new anthraquinone compound named rhynchotechol. Its structure has been proved to be 1, 6-dihydroxy-7,8-dimethoxy-2-methyl-9, 10-anthraquinone by spectrai analyses and chemical methods.The signals of all carbons in ¹³CNM R of rhynchotechol have been assigned.