A rapid, sensitive and reproducible high performance liquid chromatography （HPLC） method with post-column fluorescence derivatization has been developed to determine the amount of low-molecular- weight sulfated poly...A rapid, sensitive and reproducible high performance liquid chromatography （HPLC） method with post-column fluorescence derivatization has been developed to determine the amount of low-molecular- weight sulfated polysaccharide （GFS） in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection, and its pharmacokinetic parameters were determined to be as follows： half-time of distribution phase （t1/2α）=11.2±2.93 min, half-time of elimination phase （tl/2α）=98.20±25.78 min, maximum concentration （Cmax）=110.53 gg/mL and peak time （Tmax）=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However, the concentration of GFS found in serum was too low for detection, and GFS could only be detected for up to 2 h after intragastric administration （200 mg/kg body weight）. Thus, the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion, HPLC with post-column derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.展开更多
Polyurethane-conjugated HgS nanocrystals with tunable sizes prepared by using biomimetic method. The obtained HgS nanoparticles with good dispersibility were characterized by Fourier transform infrared. Scanning elect...Polyurethane-conjugated HgS nanocrystals with tunable sizes prepared by using biomimetic method. The obtained HgS nanoparticles with good dispersibility were characterized by Fourier transform infrared. Scanning electron microscopy are used to envisage the binding of nanoparticles with functional groups. The polyurethane molecules can control nucleation and growth of HgS crystals by binding on the surface of nanocrystals to stabilize nanoparticles. Quantum confinement effect of polyurethane-conjugated HgS nanocrystals was confirmed by UV-Vis spectra. The nanoparticles exhibit a well-defined emission feature at about 291 nm. The fluorescence results reveal that the PU/HgS nanoparticles film is sensitive to Ba2＋, and a small amount of Ba2＋ makes the emissions increase rapidly. The emission is hardly affected by other common ions in water. The nanocomposite film is possible to become a special sensor material for Ba2＋.展开更多
A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysi...A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and ^1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.展开更多
WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide...WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide skeleton,which is biosynthesized by nonribosomal peptide synthetases(NRPS).The regioselective cyclization in the last step of NRPS catalysis,which is proposed to be catalyzed by a thioesterase(TE)domain in the last module,has not been experimentally characterized.We here report the synthesis of two substrate mimics(1 and 2)of the TE(WS9326 A-TE)in WS9326 A biosynthesis,by using Fmoc-based solid-phase peptide synthesis(SPPS)method.Compounds 1 and 2 are new compounds whose structures have been elucidated based on NMR and HRESIMS analyses.The N-terminal cinnamoyl moiety and C-terminal methylated L-Ser moiety in 2 were incorporated under the mild SPPS conditions.Given the isolation difficulties of substrate of WS9326 A-TE from the Streptomyces producers of WS9326 A,our synthesis of 1 and 2 set the stage for the reconstitution of WS9326 A-TE’s catalytic reaction in vitro in the future.展开更多
基金Supported by the National Natural Science Foundation of China(No.41376166)the Ocean Public Welfare Scientific Research Project(Nos.201005024,201405040)+1 种基金the Jiangsu Science and Technology Project(No.BE2012687)the Special Fund for Cooperation between Jilin Province and Chinese Academy of Sciences(No.2013SYHZ0023)
文摘A rapid, sensitive and reproducible high performance liquid chromatography （HPLC） method with post-column fluorescence derivatization has been developed to determine the amount of low-molecular- weight sulfated polysaccharide （GFS） in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection, and its pharmacokinetic parameters were determined to be as follows： half-time of distribution phase （t1/2α）=11.2±2.93 min, half-time of elimination phase （tl/2α）=98.20±25.78 min, maximum concentration （Cmax）=110.53 gg/mL and peak time （Tmax）=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However, the concentration of GFS found in serum was too low for detection, and GFS could only be detected for up to 2 h after intragastric administration （200 mg/kg body weight）. Thus, the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion, HPLC with post-column derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.
基金This work was supported by the National Natural Science Foundation of China （No.21102121）, the Shaanxi Province Council （No.2014JQ2077）, the China＇s Scholarship Council （No.2013JK0643）, and the Xianyang Normal University Council （No.13XSYK021）.
文摘Polyurethane-conjugated HgS nanocrystals with tunable sizes prepared by using biomimetic method. The obtained HgS nanoparticles with good dispersibility were characterized by Fourier transform infrared. Scanning electron microscopy are used to envisage the binding of nanoparticles with functional groups. The polyurethane molecules can control nucleation and growth of HgS crystals by binding on the surface of nanocrystals to stabilize nanoparticles. Quantum confinement effect of polyurethane-conjugated HgS nanocrystals was confirmed by UV-Vis spectra. The nanoparticles exhibit a well-defined emission feature at about 291 nm. The fluorescence results reveal that the PU/HgS nanoparticles film is sensitive to Ba2＋, and a small amount of Ba2＋ makes the emissions increase rapidly. The emission is hardly affected by other common ions in water. The nanocomposite film is possible to become a special sensor material for Ba2＋.
基金Project supported by the National Key Project for Basic Research （No.2003CB114404）, High-tech Research and Development Program of China （No. 2002AA217131）, the National Natural Science Foundation of China （Nos. 20442003 and 20362004） and Program for New Century Excellent Talents in University of China （No. NCET-04-0912）.
文摘A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and ^1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.
基金National Natural Science Foundation of China(Grant No.21877002,81673332,81573326 and 81741148)
文摘WS9326 A is a tachykinin receptor antagonist and quorum sensing inhibitor discovered from several Streptomyces strains.The structure of WS9326 A features a(Z)-pentenylcinnamoyl moiety attached on a cyclic depsipeptide skeleton,which is biosynthesized by nonribosomal peptide synthetases(NRPS).The regioselective cyclization in the last step of NRPS catalysis,which is proposed to be catalyzed by a thioesterase(TE)domain in the last module,has not been experimentally characterized.We here report the synthesis of two substrate mimics(1 and 2)of the TE(WS9326 A-TE)in WS9326 A biosynthesis,by using Fmoc-based solid-phase peptide synthesis(SPPS)method.Compounds 1 and 2 are new compounds whose structures have been elucidated based on NMR and HRESIMS analyses.The N-terminal cinnamoyl moiety and C-terminal methylated L-Ser moiety in 2 were incorporated under the mild SPPS conditions.Given the isolation difficulties of substrate of WS9326 A-TE from the Streptomyces producers of WS9326 A,our synthesis of 1 and 2 set the stage for the reconstitution of WS9326 A-TE’s catalytic reaction in vitro in the future.
