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101.
GuoQiangHU WenLongHUANG HaiWANG 《中国化学快报》2005,16(1):1-3
4-Amino-5-(pyridin-3-yl)-4H-l,2,4-triazole-3-thiol 1 were condensed with 2-bromo-l-(substituted phenyl)ethanone to give pyridinyltriazolothiadiazines 2a-c, which were quaternarized with methyl iodide and oxidized with 30 % hydrogen peroxide to afford the corresponding methyl pyridinium salts 3a-c and pyridine- 1 -oxides 4a-c, respectively. The redtiction of compounds 3 and 4 with NaBH4 in methanol produced the target compounds 1-methyl- 1.2.5.6-tetrahydropyridin-3-yl)-6-aryl-s-triazolothiadiazines 5a-c and 3-( l-hydroxyl- 1, 2, 5, 6-tetrahydropyridin -3-yl)-6-aryl-s-triazolothiadiazines 6a-c, respectively. The endothelium vascular relaxing activity of the target compounds was screened. 相似文献
102.
Qian LIU Gang FANG Li Ping WU Jian Mei CUI Xiao Tian LIANG Song WU Institute of Materia Medica Peking Union Medical College & Chinese Academy of Medical Sciences Beijing 《中国化学快报》2004,15(12)
A stereoselective and economic synthesis of the carbapenem sidechain (2S, 4S)-4-ace-tylsulphanyl-2-[(S)1-phenylethyl-carbamoyl] pyrrolidine-1-carboxylic acid 4-nitrobenzylester was developed. Due to the effect of spatial hindrance, only the (2S,4S) diastereomer 3 wasobtained by coupling 1 and the inexpensive racemic 2 catalyzed by EEDQ. 相似文献
103.
IntroductionCriticalmicelleconcentration (cmc)ofsurfactantsinaqueoussolutionisoneofthemostusefulparametersforcharacterizingthepropertiesofsurfactants.Overaverynarrowconcentrationrangearoundthecmctransitionsoftheexistenceofsurfactantsoccurfrommonomer ,premicel lartomicellar .Andcompanyingthesetransitions ,manyotherimportantpropertiesofsurfactantsolution ,suchassurfacetension ,interfacialtension ,conductivity ,osmoticpressure ,detergency ,emulsification ,foamingandsoon ,alsochangesharplyatthepoi… 相似文献
104.
巯基棉富集-氢化物原子荧光法测定地下水中超痕量铅、汞 总被引:8,自引:0,他引:8
本文对巯基棉同时富集铅,汞的条件及洗脱条件,氢化物-原子荧光法测定铅、汞的条件及干扰元素进行探讨,并拟定了测定地下水中超痕量铅、汞的灵敏、可靠的分析方法,实验结果表明,此方法的各项指标均满足地下水分析要求。 相似文献
105.
Orotic acid is an intermediate in the pathway of pyrimidine synthesis. It is an important substance but difficult to analyze in biological samples because it is present in trace amount in normal human urine, but greatly increased in inherited metabolic diseases and drug treatment. The methods used to determine orotic acid in urine were mainly high performance liquid chromatography (HPLC)1 and capillary zone electrophoresis (CZE)2. To date, the analysis of orotic acid in urine with SFC h… 相似文献
106.
Tai Sheng LU Yang Hua YI* Shi Long MAO Da Zheng ZHOU Qiang Zhi XU Hai Feng TANG Shu Yu ZHANG Center of Marine Drug Research School of Pharmacy Second Military Medical University Shanghai 《中国化学快报》2001,(8)
Cassia siamea Lam. (CSL) is a common tree in the southern part of China. It has been used as folk medicine for aperient, antiarthritic and swellings1. We report here the isolation and structural elucidation of a new chromone glucoside, 2-methyl-5-propyl-7, 12-dihydroxy chromone-12-O-(-D-glucopyranoside (1), from the n-butanol-soluble fraction of CSL extract . 1The 80% ethanolic extract of CSL was dissolved in water and partitioned with petroleum ether, dichloromethane and n-butanol. The … 相似文献
107.
GUO Xing-gang DONG Xin-shu CHEN Jie The Affiliated Tumor Hospital of Harbin Medical University Harbin P. R. China 《高等学校化学研究》2009,25(2)
To explore the functional mechanism of tetraarsenic tetrasulfide(As4S4)against the growth and proliferation of colon cancer cells ls174t,MTT method was used to observe the functions of tetraarsenic tetrasulfide for the inhibition of cells ls174t in vitro.Transmission electron microscope was used to observe cell morphologies.FCM assay was performed to measure the change of cell cycle.RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA.Westernblot method was used to detect the expressions of bcl-2 and bax protein.Tetraarsenic tetrasulfide showed an inhibiting effect on the proliferation of cells ls174t in vitro(P<0.01).It induces the apoptosis of cells ls174t,which is related to the decrease in the expression of bcl-2 and the increase in the expression of bax. 相似文献
108.
Shao Yong Li Bei Sun Zhi Chao Xiao Ming Hui Huang Wei Xue Xie Jun Min Liu 《中国化学快报》2009,20(6):640-642
A one-step procedure is developed to synthesize inherently chiral p-tert-butylcalix[4]azacrown 1 through etherification between p-tert-butylcalix[4]arene and compound 3, which can be amplified to efficiently prepare more inherently chiral calix[4]arenes in ABHH substitution pattern. 相似文献
109.
A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method.With highly polar groups,the ligand can be recycled and reused eight times to prepare ethyl(2R,3S)-2,3-dihydroxy-3-phenylpropionate with high yield and ee via asymmetric dihydroxylation(AD) reaction. 相似文献
110.
Zhi Li Li Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic Medicine Peking Union Medical College Beijing China 《中国化学快报》2009,20(2):204-206
The catalytic and signaling activities of insulin receptor kinase(IRK)are regulated by the autophosphorylation of three tyrosine residues in a cytoplasmic protein-tyrosine kinase domain at Tyro 1158,Tyro 1162 and Tyro 1163.In this study,time-course of the auphosphorylation of the core kinase(residues 978-1283)from IRK was directly investigated by online electrospray ionization mass spectrometry.It is found that two tyrosine residues were phosphorylated in reaction time range of 30 min.This study implies ... 相似文献