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 a...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.展开更多
In this paper, the fully anisotropicoverall tumbling motions and side groups internal rotation of ocotillol-type saponins separated from the leaves of Panax Quidquefolium L. are investigated by <sup>13</sup&g...In this paper, the fully anisotropicoverall tumbling motions and side groups internal rotation of ocotillol-type saponins separated from the leaves of Panax Quidquefolium L. are investigated by <sup>13</sup>C nuclear magnetic relaxation. The fully anisotropic overall tumbling motion model with methyl conformation jumps internal rotation among three equivalent sites is presented, and the spectral density function of this model is derived. The rotation rates for overall tumbling motions to ocotillol-type saponins （OTS） are computed by Woessner’s fully anisotropic overall tumbling motion model, and the internal rotation rate and barrier for side groups in OTS are calculated using free diffusion internal rotation model, restriction diffusion internal rotation model and conformation jumps internal rotation model, respectively.展开更多
基金Supported by the National Natural Science Foundation of China（No.31201295）.
文摘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.
基金Project supported by the National Natural Science Foundation of China and the State Key Laboratory of Applied Organic Chemistry, Lanzhou University.
文摘In this paper, the fully anisotropicoverall tumbling motions and side groups internal rotation of ocotillol-type saponins separated from the leaves of Panax Quidquefolium L. are investigated by <sup>13</sup>C nuclear magnetic relaxation. The fully anisotropic overall tumbling motion model with methyl conformation jumps internal rotation among three equivalent sites is presented, and the spectral density function of this model is derived. The rotation rates for overall tumbling motions to ocotillol-type saponins （OTS） are computed by Woessner’s fully anisotropic overall tumbling motion model, and the internal rotation rate and barrier for side groups in OTS are calculated using free diffusion internal rotation model, restriction diffusion internal rotation model and conformation jumps internal rotation model, respectively.
