The Study Of C₂₁ Steroidal Fraction Degradation Product Of Marsdenia Tenacissima

The stem of Marsdenia tenacissima(Roxb.) Wight et Arn.(Asclepiadaceae),known as "Tong-guang-teng" in Chinese folk medicine,the related preparation from Marsdenia tenacissima effective to malignant tumor such as gastric carcinoma,lung cancer,liver cancer,etc.We adopted MTT method to detect the effects of C₂₁ steroidal fraction and the degradation product of Marsdenia tenacissima on cytotoxic activity,the results indicated that the degradation product of Marsdenia tenacissima obviously inhibit the proliferation of some tumor cell lines such as SGC-7901 and MGC-803 human gastric cancinoma cell line,better than the effect of C₂₁ steroidal fraction of Marsdenia tenacissima;Synthetically using modern separation method and techniques,from C₂₁ steroidal fraction degradation product of Marsdenia tenacissima four main compounds were isolated,and their structures were elucidated by a combination of ESI-MS and 1D,2D-NMR techniques as 11α-O-tigloyl-12β-O-acetyl-tenaci -geninB,12β-O-2-methylbutyryl-tenacigeninA,11α-O-2-methylbutyryl-12β-O-acetyl-tenaci -geninB,11α-O-2-methyl-butyryl-12β-O-benzoyl-tenacigeninB;Through parallel test and orthogonal test to optimize the preparation technology of degradation product,the optimal degrade conditions as followed:the reaction medium is 10 times aqueous solution,the catalyst is 1.0%sulphuric acid solution,the temperature of degradation is 80℃,and the time of degradation is 4 hours;In order to establish the method to evaluate the quality of crude drugs Tong-guang-teng,the colorimetric method was used to determine the steroidal sapogenins contents of C₂₁ steroidal fraction and the degradation product of Marsdenia tenacissima,and a HPLC method was developed to determine the contents of 11α-O-tigloyl-12β-O-acetyl-tenaci -geninB,simultaneously.The discrepancy of 11α-O-tigloyl-12β-O-acetyl-tenacigeninB in Marsdenia tenacissima from different regions were obvious,the content was highest in Linchang of Yunnan province,and was lowest in Zhaotong of Yunnan province.This paper mainly describes the chemical composition,preparation technology and quality control of C₂₁ steroidal fraction degradation product of Marsdenia tenacissima,The study benefits will provide theoretical basis to develop new drug possessing self-governed intellectual property,which is important both theoretically and practically.