2 methylanthraquinone/rubia cordifolia

From roots of Rubia cordifolia L. two anthraquinones are isolated: 1,4-dihydroxy 2-methylanthraquinone and 1,5-dihydroxy 2-methylanthraquinone and 3-prenyl methoxy 1,4-naphthoquinone.

From roots of Rubia cordifolia L. four anthraquinones are isolated: 1-hydroxy 2-methylanthraquinone and nordamnacanthal which have been already isolated in some Rubiaceae, physcion which seems to be new in this family and 1,4-dihydroxy 6-methyl-anthraquinone which seems to be a new quinizarin.

OBJECTIVE To search alpha-glucosidase inhibitors from Rubia cordifolia. METHODS The alpha-glucosidase inhibitors were isolated by the column chromatographic techniques and the bioassay-guided method in vitro. A combination of MS and NMR spectroscopy was used to identify the chemical structures. The

A new anthraquinone, Rubiacordone A (1) (6-acetoxy-1-hydroxy-2-methylanthraquinone-3-O-alpha-L-rhamnopyranoside), was isolated together with the known anthraquinone, 1-acetoxy-6-hydroxy-2-methylanthraquinone-3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside] (2), from the dried roots of