Semisynthesis and Cytotoxicity Evaluation of a Series of Ocotillol Type Saponins and Aglycones from 20（S）-Ginsenoside Rg2, Rhl, Protopanaxatriol and Their 20（R）-Epimers

• Published in: 高等学校化学研究：英文版 2016 (1), p.35-40
• Main Author: YANG Jie YU Xue CAI Xiaoxiang CHEN Yanxin ZANG Huiming LI Xuwen JIN Yongri
• Format: Article
• Language: English
• Subjects: HeLa细胞; MCF-7细胞; 人参皂苷Rg2; 半合成; 差向异构体; 毒性评价; 细胞系; 西洋参
• ISSN: 1005-9040; 2210-3171

Abstract With the oxidation treatment, eighteen compounds were separated from 20（S）-ginsenoside Rg2, Rhl, pro- topanaxatriol（PPT） and their 20（R）-epimers in total and cytotoxicity of most of them was evaluated against three hu- man cancer cell lines HeLa, A549 and MCF-7 by 3-（4,5-dimetylthiazol-z-yl）-2,5-diphenyltetrazolium bromide（MTT） assay. Their structures were confirmed by means of nuclear magnetic resonance（NMR） and mass spectrometry and the results were compared with those of previous literature. In this study, we systematically semisynthesized all four ocotillol type saponins, i.e., （20S, 24S＇）, （20S, 24R）, （20R, 24S） and （20R, 24R）. All the configurations at C20 kept the same with their starting materials. Meanwhile a pair of C24 epimers was generated in terms of ocotillol type saponins In addition, seven compounds（4--8, 13 and 14） were reported firstly. The cytotoxic results distinguished the ocotillol type products（6, 7, 13 and 14） from 20（R）-PPT and 20（R）-ginsenoside Rhl, which possessed better cytotoxicities than their correspondents from 20（S）-epimers against HeLa cells, and the carbonyl group at C3 can improve the cytotoxi- city, which helped us to gain deeper insight into Ocotillol type saponins.