Three known pterocarpin derivatives, (-)-medicarpin (PDI), (-)-2-hydroxy-4,9-dimethoxypterocarpan (PD2), and 4- hydroxy-3-methoxy-8,9-methylene-dioxypterocarpan (PD3) were isolated from Canavalia maritima, f...Three known pterocarpin derivatives, (-)-medicarpin (PDI), (-)-2-hydroxy-4,9-dimethoxypterocarpan (PD2), and 4- hydroxy-3-methoxy-8,9-methylene-dioxypterocarpan (PD3) were isolated from Canavalia maritima, for the first time. The cytotoxic and pro-apoptotic activities of (-)-medicarpin in cutured human tumor HeLa cells and its effect on NF-r,B activation were investigated. We found that PD1 inhibited NF-r,B activation by high content screening analysis, and PD1 exhibited cytotoxicity by SRB assay. In addition, we found that PD1 induced nuclear condensation and increased membrane permeability and mitochondrial transmembrane potential in HeLa cells in a dose and time dependent manner. In conclusion, our data suggested that (- )-medicarpin was capable of inhibiting tumor cell growth in vitro and inducing apoptosis, which might be via the suppression of NF-kB activation.展开更多
Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide inste...Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring tide.To explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the Pearl River Estuary,and the adjacent sea.Numerical experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the sea.Specific topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring tide.As a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate tide.This is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate tide.Besides,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.展开更多
基金National High Technology Development Project (863 Project,Grants No.2006AA09Z446,2006AA09Z405 and 2006DFA31100)NSFC(Grants No.30672607,30901845)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry.
文摘Three known pterocarpin derivatives, (-)-medicarpin (PDI), (-)-2-hydroxy-4,9-dimethoxypterocarpan (PD2), and 4- hydroxy-3-methoxy-8,9-methylene-dioxypterocarpan (PD3) were isolated from Canavalia maritima, for the first time. The cytotoxic and pro-apoptotic activities of (-)-medicarpin in cutured human tumor HeLa cells and its effect on NF-r,B activation were investigated. We found that PD1 inhibited NF-r,B activation by high content screening analysis, and PD1 exhibited cytotoxicity by SRB assay. In addition, we found that PD1 induced nuclear condensation and increased membrane permeability and mitochondrial transmembrane potential in HeLa cells in a dose and time dependent manner. In conclusion, our data suggested that (- )-medicarpin was capable of inhibiting tumor cell growth in vitro and inducing apoptosis, which might be via the suppression of NF-kB activation.
基金supported by the "Creative Research Group" of National Natural Science Foundation of China (Grant No. 41021064)the National Basic Scientific Research Program of Global Change (Grant No.2010CB951201)Marine Special Program for Scientific Research on Public Causes (Grant No. 200705019)
文摘Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring tide.To explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the Pearl River Estuary,and the adjacent sea.Numerical experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the sea.Specific topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring tide.As a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate tide.This is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate tide.Besides,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.