Studies On The Mechanism Of Put In Later Of Uncaria Hook And Structure Modification Of Gentiopicroside

In the traditional Chinese medicine (TCM), the uncaria hook is one of the most useful herbs. In the compound prescription of the TCM, uncaria hook usually put in 15 minutes before the other herbs decocted ready. In order to investigate the mechanism of put in later of uncaria hook in compound prescription, the extract of uncaria hook was treated in the low and high temperature respectively, and the constituents were compared with thin layer chromatography and column chromatography. Two constituents were disappeared during the high temperature treatment, while three new constituents were created during the process. The five constituents were isolated by the column chromatography and the molecular weight of which were determined by electro-spray mass spectrometry. The molecular weight of two disappeared constituents were 350 and 670, while three new constituents, one of which included two compounds were 373, 383, 577, 611 respectively. Accurate structure of these six compounds were not fully established yet.Two new compounds with molecular weight 194 were obtained in the modification of gentiopicroside by enzyme and yeast. It was reported that gentiopicroside was not stable and decomposed in acid or alkaline mediate. We proposed with experimental evidence that the decomposed products were similar with the compounds we got above.Erythrocentaurin was synthesized by the biomimetic method from gentiopicroside. When we isolated the erythrocentaurin from gentiana macrophylla Pall as a comparative sample, it was failed. We could not find the erythrocentaurin by the gas chromatography-mass spectrometry. It was suggested that erythrocentaurin was a transformation product from gentiopicroside during the extracted process, not existed in the plant really.