RESUMO
Objective: To investigate, purify, and characterize the active ingredients in the aqueous extract from Sappan Lignum (the dry heartwood of Caesalpinia sappan). Methods: HPLC-MS/MS was used in the analysis of the chemical constituents in the aqueous extract from Sappan Lignum. Then the inhibitory effect of the aqueous extract from Sappan Lignum on human bladder tumor cell line T24 in vitro was studied. The main chemical constituents were purified by column chromatography and their structures were characterized by NMR. Results: In the aqueous extract from Sappan Lignum, 16 compounds were separated and detected well by HPLC-MS/MS and 14 were identified. The main compounds were quercetin, brazilin, isoliquiritigeni, protosappanin B, brazil A, 3'-deoxysappanol, 4-O-hydroxybrazilin, sappanchalcone, and (αS)-α, 2', 4, 4'-tetrahydroxy dihydrochalcone. The killing rate of cancer cells was positively correlated to the concentration of the main component which was brazilin. At last, according to the purification by column chromatography and the structural characterization by NMR, we obtained the pure brazilin in the aqueous extract from Sappan Lignum. Conclusion: The research offers a new method for the identification of the components in the aqueous extract from Sappan Lignum and provides a basis for the medicinal functions of Sappan Lignum for future study.