Studies on a novel anthraquinone and its glycosides isolated from Rubia cordifolia and R. akane.

Abstract

From Radix Rubiae (dried roots of Rubia cordifolia), mollugin, 1-hydroxy-2-methyl-9, 10-anthraquinone, alizarin, 1, 3-dihydroxy-2-ethoxymethyl-9, 10-anthraquinone, lucidin primeveroside, ruberythric acid and three new anthraquinones, 2-methyl-1, 3, 6-trihydroxy-9, 10-anthraquinone, 2-methyl-1, 3, 6-trihydroxy-9, 10-anthraquinone 3-O-(6'-O-acetyl)-α-rhamnosyl-(1→2)-β-glucoside and 2-methyl-1, 3, 6-trihydroxy-9, 10-anthraquinone 3-O-α-rhamnosyl (1→2)-β-glucoside, were isolated. The new anthraquinone glycosides were also obtained from the roots of R. akane, as the main chemical constituents of anthraquinone glycosides. The structures were established by various chemical and spectroscopic methods.