Three new C21 steroidal glycosides named komaroside A, komaroside B, komaroside C were isolated from the ethanolic extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae), their structures were determ...Three new C21 steroidal glycosides named komaroside A, komaroside B, komaroside C were isolated from the ethanolic extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae), their structures were determined by physiochemical and spectroscopic analysis.展开更多
Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectrosco...Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectroscopic and chemical methods.展开更多
AIM: To construct pEGFP-hepatocyte growth factor (HGF) expression vector, the to detect its expression in transfected human hepatocytes, and to investigate the influence of autocrine HGF expression on the proliferativ...AIM: To construct pEGFP-hepatocyte growth factor (HGF) expression vector, the to detect its expression in transfected human hepatocytes, and to investigate the influence of autocrine HGF expression on the proliferative potential and cytoprotective effects in human hepatocytes.METHODS: Human HGF cDNA was ligated to the pEGFP vector. Recombinant plasmid was transfected into human hepatocyte line QZG with liposome. Expression of HGF protein was observed by fluorescence microscopy and immunohistochemistry. Hepatic cells were collected 24, 48, and 72 h after transfection to detect the number of [^3H]-TdR uptake in DNA. DNA synthesis was observed by using PCNA stain immunohistochemistry.Acute liver cell damage was induced by carbon tetrachloride. Cytoprotective effect was observed by examining the survival rate of hepatocytes and leakage of intracellular alanine transaminase (ALT) and potassium ions.RESULTS: HGF identification of pEGFP-HGF by enzyme digestion showed that HGF fragment was cloned into BamH I and SalI sites of pEGFP-N3. Expression of GFP in transfected hepatocytes was observed with fluorescence microscopy. The [^3H]-TdR uptake became 7 times as many as in thecontrol group 96 h after transfection. After HGF transfection, the survival rate of hepatocytes poisoned by CCI4 significantly increased (83% vs 61%, P<0.05), and the leakage of intracellular alanine transaminase and potassium ions decreased (586 nkat/L vs 1089 nkat/L, P<0.01; and 5.59 mmol/L vs 6.02 mmol/L, P<0.01 respectively). Culture of transfected hepatic cells promoted the proliferation of other nontransfected cells.CONCLUSION: Transfected HGF is expressed in hepatic cells and has the activity of promoting cell division and protecting hepatic cells against poisoning.展开更多
Two new xanthones, 1, 6, 8-trihydroxy-2, 3-methylenedioxyxanthone 1 and 1, 4-di- hydroxy-6, 7-methylenedioxyxanthone 2, were isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spec...Two new xanthones, 1, 6, 8-trihydroxy-2, 3-methylenedioxyxanthone 1 and 1, 4-di- hydroxy-6, 7-methylenedioxyxanthone 2, were isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spectroscopic and chemical methods.展开更多
We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an ext...We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral genome replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.展开更多
Abstract: The Dai medicinal plant Winchia calophylla A. DC. (Apocynaceae) has efficacy as an anti-cough and anti-asthmatic medication. In order to investigate its relative bioactive components, we studied the chemical...Abstract: The Dai medicinal plant Winchia calophylla A. DC. (Apocynaceae) has efficacy as an anti-cough and anti-asthmatic medication. In order to investigate its relative bioactive components, we studied the chemical constituents of this plant. Using repeated column chromatography, 28 compounds, including loganin, six phenolic compounds, 17 indole alkaloids, three pyridine alkaloids, and a quinoline alkaloid, were isolated from the stem barks of W. calophylla. Loganin, paeonol, N (4)-methyl akuammicine, and cantleyine exhibited a moderate relaxation effect on isolated smooth muscles of guinea-pig tracheal spirals and lung strips and may be the bioactive components responsible for the bronchodilation produced by W. calophylla.展开更多
This paper summarizes atmospheric aerosol concentrations of 5 stratospheric balloon soundings during the period from 1984 to 1994. Aerosol-rich layers in the troposphere were detected and the causes were analyzed. Th...This paper summarizes atmospheric aerosol concentrations of 5 stratospheric balloon soundings during the period from 1984 to 1994. Aerosol-rich layers in the troposphere were detected and the causes were analyzed. The main results are as follows: (1) the vertical distribution of the atmospheric aerosol is affected by atmospheric dynamic processes, humidity, etc.; (2) the tropospheric column concentrations of aerosol were 72.2×105, 20.2×105, 20.7×105 and 34.4×105 cm-2 and occupying 81%, 61% and 60% of the 0-to-30 km aerosol column, on Aug. 23, 1984, Aug. 22, 1993, Sept. 12, 1993 and Sept. 15, 1994, respectively; (3) the effect of volcano eruption was still evident in the aerosol profiles, 28 and 27 months after the El Chichon and Pinatubo eruption; (4) the aerosol concentration in the troposphere did not decrease at all heights as atmospheric aerosol model.展开更多
文摘Three new C21 steroidal glycosides named komaroside A, komaroside B, komaroside C were isolated from the ethanolic extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae), their structures were determined by physiochemical and spectroscopic analysis.
基金supported by the National Natural Science Foundation for Outstanding Young Scientists to Prof.Xiao Jiang Hao(No.39525025).
文摘Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectroscopic and chemical methods.
基金Supported by National Natural Science Foundation of China,No.30170927 and No.3007021
文摘AIM: To construct pEGFP-hepatocyte growth factor (HGF) expression vector, the to detect its expression in transfected human hepatocytes, and to investigate the influence of autocrine HGF expression on the proliferative potential and cytoprotective effects in human hepatocytes.METHODS: Human HGF cDNA was ligated to the pEGFP vector. Recombinant plasmid was transfected into human hepatocyte line QZG with liposome. Expression of HGF protein was observed by fluorescence microscopy and immunohistochemistry. Hepatic cells were collected 24, 48, and 72 h after transfection to detect the number of [^3H]-TdR uptake in DNA. DNA synthesis was observed by using PCNA stain immunohistochemistry.Acute liver cell damage was induced by carbon tetrachloride. Cytoprotective effect was observed by examining the survival rate of hepatocytes and leakage of intracellular alanine transaminase (ALT) and potassium ions.RESULTS: HGF identification of pEGFP-HGF by enzyme digestion showed that HGF fragment was cloned into BamH I and SalI sites of pEGFP-N3. Expression of GFP in transfected hepatocytes was observed with fluorescence microscopy. The [^3H]-TdR uptake became 7 times as many as in thecontrol group 96 h after transfection. After HGF transfection, the survival rate of hepatocytes poisoned by CCI4 significantly increased (83% vs 61%, P<0.05), and the leakage of intracellular alanine transaminase and potassium ions decreased (586 nkat/L vs 1089 nkat/L, P<0.01; and 5.59 mmol/L vs 6.02 mmol/L, P<0.01 respectively). Culture of transfected hepatic cells promoted the proliferation of other nontransfected cells.CONCLUSION: Transfected HGF is expressed in hepatic cells and has the activity of promoting cell division and protecting hepatic cells against poisoning.
文摘Two new xanthones, 1, 6, 8-trihydroxy-2, 3-methylenedioxyxanthone 1 and 1, 4-di- hydroxy-6, 7-methylenedioxyxanthone 2, were isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spectroscopic and chemical methods.
文摘We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral genome replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.
文摘Abstract: The Dai medicinal plant Winchia calophylla A. DC. (Apocynaceae) has efficacy as an anti-cough and anti-asthmatic medication. In order to investigate its relative bioactive components, we studied the chemical constituents of this plant. Using repeated column chromatography, 28 compounds, including loganin, six phenolic compounds, 17 indole alkaloids, three pyridine alkaloids, and a quinoline alkaloid, were isolated from the stem barks of W. calophylla. Loganin, paeonol, N (4)-methyl akuammicine, and cantleyine exhibited a moderate relaxation effect on isolated smooth muscles of guinea-pig tracheal spirals and lung strips and may be the bioactive components responsible for the bronchodilation produced by W. calophylla.
文摘This paper summarizes atmospheric aerosol concentrations of 5 stratospheric balloon soundings during the period from 1984 to 1994. Aerosol-rich layers in the troposphere were detected and the causes were analyzed. The main results are as follows: (1) the vertical distribution of the atmospheric aerosol is affected by atmospheric dynamic processes, humidity, etc.; (2) the tropospheric column concentrations of aerosol were 72.2×105, 20.2×105, 20.7×105 and 34.4×105 cm-2 and occupying 81%, 61% and 60% of the 0-to-30 km aerosol column, on Aug. 23, 1984, Aug. 22, 1993, Sept. 12, 1993 and Sept. 15, 1994, respectively; (3) the effect of volcano eruption was still evident in the aerosol profiles, 28 and 27 months after the El Chichon and Pinatubo eruption; (4) the aerosol concentration in the troposphere did not decrease at all heights as atmospheric aerosol model.
