[Studies on the chemical constituents of Rhynchotechum vestitum Hook. F. et Thoms].

ABSTRACT

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 beta-sitosterol (I), lupeol (II), rubiadin 1-methylether (III) and rubiadin (IV). The fifth, an orange needle crystal (C17H14O6, mp 236, 5-238 degrees C) 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 spectral analyses and chemical methods.