| Rubia cordifolia, known as Qiancao in Chinese, has been used as a traditional Chinese medicine for the treatment of cough, joint inflammation, and uterine hemorrhage. Pharmacological studies have demonstrated that the major chemical constituents from R. cordifolia have anticancer, antioxidant activities. This thesis focused on evaluation of the antioxidant activities and the counter-current chromatographic separation of bioactive components from R. cordifolia.The Extracts of R. cordifolia obtained by reflux with ethanol were divided into several fractions through different kinds of solvent's extraction and silica column chromatographic separation. The antioxidant activity of these fractions were evaluated by DPPH- radical-scavenging assay. The result indicates that the fraction extracted by light petroleum and by light petroleum and ethyl acetate at a volume ratio of 1:1 showed a strong antioxidant activity.A preparative HSCCC method for direct isolation and purification of the bioactive component mollugin from the ethanol extract of R. cordifolia was successfully established using light petroleum/ethanol/diethyl ether/water as the two-phase solvent system. By controlling the flow rates of the mobile phase, two HSCCC methods for rapid analysis and preparative isolation and purification of the three target compounds were established. And three components tectoquinone, 1-hydroxy-2-methylanthraquinone, and mollugin were separated successfully from the crude petroleum extract of R. cordifolia. A stepwise elution mode was introduced in the separation and purification of bioactive component from the fraction eluted by light petroleum and ethyl acetate (1:1, v/v). Composed using semi-preparative HPLC, four compounds were separated.The antioxidant activity of all compounds separated by HSCCC were investigated by DPPH- radical-scavenging assay. And the results showed that four compounds have good bioactivity.
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