Separation and quantitative analysis of anthraquinones in Morinda officinalis How. by HPLC

Morinda officinalis How.(Rubiaceae) is used in folk medicine as a tonic, warming, sex impulse and anti-inflammatory agent in Asia. From n-hexane and ethylacetate extracts of the root of Morinda officinalis How., we have isolated two known anthraquinones compounds and their structures were identified rubiadin(I) and rubiadin-1-methyl ether(II) by NMR. Our object was to determine the rubiadin-1-methyl ether content in root of M. officinalis by HPLC-PDA. Chromatography was performed using a reversed-phase system with Luna C₁₈ column, flow rate 1.0 mL/min, UV 280nm and acetonitrile-water (50:50, v/v), as the mobile phase. The rubiadin-1-methyl ether content of M. officinalis from four different districts in Korea were determined to be 0.013%.