As the increases of climatic aridity and grazing intensity, shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions, and its abundance also generally increases. However, the eff...As the increases of climatic aridity and grazing intensity, shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions, and its abundance also generally increases. However, the effects of climatic aridity and grazing intensity on sexual reproduction of shrubs in grassland remain largely unclear. In order to understand the effects of grazing intensity and climatic drought stress, and their interaction on seed production of shrub species, we examined the seed number, seed weight and seed yield of Caragana stenophylla under three grazing intensities （fenced, mild grazing and severe grazing） across a climatic aridity gradient （semi-arid, arid, very arid and intensively arid zones） in the Inner Mongolia Steppe, northern China during 2012-2013. The seed number, seed weight and seed yield gradually increased from the semi-arid to the very arid zones, but decreased from the very arid to the intensively arid zones in fenced plots. The seed number and seed yield decreased from the semi-arid to the intensively arid zones in mild and severe grazing treatment plots, therefore, grazing enhanced the suppression effect of climatic aridity on seed production of C. stenophylla. The seed number and seed yield gradually decreased as grazing intensity increased. The seed weight was highest in severe grazing plots, followed by the mild grazing plots and then the fenced plots. Precipitation varied interannually during the study period. We observed that the seed number seed weight and seed yield were lower in the low precipitation year （2013） than in the high precipitation year （2012）. As climatic drought stress increased, the negative effects of grazing on seed production of C. stenophylla also gradually increased. Our results indicated that climatic drought stress may contribute to the encroachment of C. stenophylla shrub in arid zones by promoting its seed production. However, grazing had negative effects on sexual reproduction of C. stenophylla, and the combined effects of drought stress and grazing seriously suppressed sexual reproduction of C. stenophylla in the intensively arid zone.展开更多
Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compou...Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compounds.Their structures were established mainly on the base of NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.In addition,the cytotoxicity of the two new saponins was tested.Graphical Abstract Two new highly oxygenated spirostanol saponins,paristenosides A(1)and B(2),were isolated from the rhizomes of Paris polyphylla var.stenophylla.Their structures were established mainly based on NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.展开更多
Five new saponins,including three steroid saponins,paristenoids A-C(1-3),and two triterpenoid saponins,paristenoids D-E(4-5),along with four known ones(6-9)were isolated from the rhizomes of Paris polyphylla var.steno...Five new saponins,including three steroid saponins,paristenoids A-C(1-3),and two triterpenoid saponins,paristenoids D-E(4-5),along with four known ones(6-9)were isolated from the rhizomes of Paris polyphylla var.stenophylla.The structures of the isolated compounds were identified nainly by detailed spectroscopic analysis,including extensive 1D and 2D NMR,MS,as well as chemical methods.Compound 3 is a new cyclocholestanol-type steroidal saponin with a rare 6/6/6/5/5 fused-rings cholestanol skeleton,and this skeleton has been first found from the genus Paris.The cytotoxicities of the isolated compounds against three human three glioma cell lines(U87MG,U251MG and SHG44)were evaluated,and compound 7 displayed certain inhibitory effect with ICso values of 15.22±1.73,18.87±1.81 and 17.64±1.69μmol^(-1),respectively.展开更多
目的对重楼属药用植物狭叶重楼(Paris.polyphylla.Smith var stenophylla Franch)的化学成分进行研究,为拓宽重楼属药用植物的资源提供科学依据。方法采用硅胶柱层析,大孔吸附树脂,葡聚糖凝胶SephadexLH-20及反相硅胶RP-C18中压液相柱...目的对重楼属药用植物狭叶重楼(Paris.polyphylla.Smith var stenophylla Franch)的化学成分进行研究,为拓宽重楼属药用植物的资源提供科学依据。方法采用硅胶柱层析,大孔吸附树脂,葡聚糖凝胶SephadexLH-20及反相硅胶RP-C18中压液相柱层析等技术分离纯化其主要化合物,根据理化性质、波谱数据鉴定其结构。结果从狭叶重楼乙醇提取物中分离并鉴定了5个甾体皂苷类单体化合物:重楼皂苷:Diosgenin-3-O-α-L-rhamnopyranosyl-(l→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-glucopyranoside;重楼皂苷V:Diosgenin-3-O-α-L-rhamnopyranosyl-(l→2)-β-D-glucopyranoside;重楼皂苷:Pennogenin-3-O-α-L-rhamnopyranosyl(1→2)-β-D-glu-copyranoside;重楼皂苷:Pennogenin-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(l→2)]-β-D-glucopyranoside;重楼皂苷H:Pennoge-nin-3-O-α-L-rhamnopyranosyl-(l→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-Glucopyranoside。结论首次从狭叶重楼中分离并鉴定出5个甾体皂苷类化合物。展开更多
基金supported by the National Natural Science Foundation of China(31570453,31170381,31270502,31300386)the PhD Candidate Research Innovation Fund of Nankai Universitythe Doctoral Fund of Tianjin Normal University(52XB1208)
文摘As the increases of climatic aridity and grazing intensity, shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions, and its abundance also generally increases. However, the effects of climatic aridity and grazing intensity on sexual reproduction of shrubs in grassland remain largely unclear. In order to understand the effects of grazing intensity and climatic drought stress, and their interaction on seed production of shrub species, we examined the seed number, seed weight and seed yield of Caragana stenophylla under three grazing intensities （fenced, mild grazing and severe grazing） across a climatic aridity gradient （semi-arid, arid, very arid and intensively arid zones） in the Inner Mongolia Steppe, northern China during 2012-2013. The seed number, seed weight and seed yield gradually increased from the semi-arid to the very arid zones, but decreased from the very arid to the intensively arid zones in fenced plots. The seed number and seed yield decreased from the semi-arid to the intensively arid zones in mild and severe grazing treatment plots, therefore, grazing enhanced the suppression effect of climatic aridity on seed production of C. stenophylla. The seed number and seed yield gradually decreased as grazing intensity increased. The seed weight was highest in severe grazing plots, followed by the mild grazing plots and then the fenced plots. Precipitation varied interannually during the study period. We observed that the seed number seed weight and seed yield were lower in the low precipitation year （2013） than in the high precipitation year （2012）. As climatic drought stress increased, the negative effects of grazing on seed production of C. stenophylla also gradually increased. Our results indicated that climatic drought stress may contribute to the encroachment of C. stenophylla shrub in arid zones by promoting its seed production. However, grazing had negative effects on sexual reproduction of C. stenophylla, and the combined effects of drought stress and grazing seriously suppressed sexual reproduction of C. stenophylla in the intensively arid zone.
基金This work is funded by the National Natural Science Funding of China(Grand No.31570363)the Key Research Program of the Chinese Academy of Sciences(Grand No.KSZDEW-Z-004-03-4)the Natural Science Foundation of Yunnan Province(Grand No.2015FA031).
文摘Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compounds.Their structures were established mainly on the base of NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.In addition,the cytotoxicity of the two new saponins was tested.Graphical Abstract Two new highly oxygenated spirostanol saponins,paristenosides A(1)and B(2),were isolated from the rhizomes of Paris polyphylla var.stenophylla.Their structures were established mainly based on NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.
基金supported by the National Natural Science Foundation of China(Nos.81973192 and 81902185)the Key Research and Development Projects of Shaanxi Province(Nos.2021ZDLSF04-07,2021SF-175 and 2022SF-314)+1 种基金the Natural Science Basic Research Program of Shaanxi Province(No.2022JQ-780)the Key Scientific Research Project of Shaanxi Administration of Traditional Chinese Medicine(No.2021-02-ZZ-003).
文摘Five new saponins,including three steroid saponins,paristenoids A-C(1-3),and two triterpenoid saponins,paristenoids D-E(4-5),along with four known ones(6-9)were isolated from the rhizomes of Paris polyphylla var.stenophylla.The structures of the isolated compounds were identified nainly by detailed spectroscopic analysis,including extensive 1D and 2D NMR,MS,as well as chemical methods.Compound 3 is a new cyclocholestanol-type steroidal saponin with a rare 6/6/6/5/5 fused-rings cholestanol skeleton,and this skeleton has been first found from the genus Paris.The cytotoxicities of the isolated compounds against three human three glioma cell lines(U87MG,U251MG and SHG44)were evaluated,and compound 7 displayed certain inhibitory effect with ICso values of 15.22±1.73,18.87±1.81 and 17.64±1.69μmol^(-1),respectively.
文摘目的对重楼属药用植物狭叶重楼(Paris.polyphylla.Smith var stenophylla Franch)的化学成分进行研究,为拓宽重楼属药用植物的资源提供科学依据。方法采用硅胶柱层析,大孔吸附树脂,葡聚糖凝胶SephadexLH-20及反相硅胶RP-C18中压液相柱层析等技术分离纯化其主要化合物,根据理化性质、波谱数据鉴定其结构。结果从狭叶重楼乙醇提取物中分离并鉴定了5个甾体皂苷类单体化合物:重楼皂苷:Diosgenin-3-O-α-L-rhamnopyranosyl-(l→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-glucopyranoside;重楼皂苷V:Diosgenin-3-O-α-L-rhamnopyranosyl-(l→2)-β-D-glucopyranoside;重楼皂苷:Pennogenin-3-O-α-L-rhamnopyranosyl(1→2)-β-D-glu-copyranoside;重楼皂苷:Pennogenin-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(l→2)]-β-D-glucopyranoside;重楼皂苷H:Pennoge-nin-3-O-α-L-rhamnopyranosyl-(l→2)-[α-L-arabinofuranosyl-(1→4)]-β-D-Glucopyranoside。结论首次从狭叶重楼中分离并鉴定出5个甾体皂苷类化合物。
