Studies on antibacterial constituents from the roots of Rubia cordifolia L.

Twelve compounds were isolated from the roots of Rubia cordifolia L.. Nine of them were established by chemical and spectroscopic methods te be alizarin (Ⅰ), 1-hydroxy-2-methyl-9, 10-anthraquinone (Ⅱ), 1, 3, 6-trihydroxy-2-methyl,-9, 10-anthra-quinone-3-O-(6'-O-acetyl)-α-L-rhamnosyl(1→2)-β-D-glucoside (Ⅲ), 1, 3, 6-trihydrozy-2-methyl-9, 10-anthraquinone-3-O-α-L-rhamnosyl(1→2)-β-D-giucoside(Ⅳ), 1, 3, 6-trihydrozy-2-methyl-9, 10-anthraquinone-3-O-(6'-O-acetyl)-β-D-glucoside(Ⅴ), 2-carbomethoxy -3-prenyl-1, 4-naphthohydroqumone d_1-β-D-glucoside(Ⅵ), rubimalim(Ⅶ), β-sitosterel (Ⅷ) and daucosterol (Ⅸ), among them, Ⅴ is a nwe compound and Ⅸ was obtained: from this genus for the first time. Ⅲ, Ⅵ and Ⅶ showed certain antibacterial activities.