Quan‐Bin Han  Lina Wong  Fanny Lai  Nian‐Yun Yang  Jing‐Zheng Song  Chun‐Feng Qiao  Hong‐Xi Xu 《Journal of separation science》2009,32(2):309-313

In order to provide the chemical markers for the quality control of herbal medicines, four diterpenoids, pseudolaric acids A and B (PAA and PAB), and their glucosides were isolated from the methanol extract of the Chinese herb Pseudolarix kaempferi using high‐speed counter‐current chromatography (HSCCC). The diphase solvent system was n‐hexane/EtOAc/MeOH/H₂O which was used at two ratios (5:5:5:5 and 1:9:4:6 by volume) in the separation of pseudolaric acids and their glycosides, respectively. As a result, PAA (14 mg), PAB (129 mg), PAA‐O‐β‐D ‐glucopyranoside (8 mg, PAAG), and PAB‐O‐β‐D ‐glucopyranoside (42 mg, PABG) were obtained from 0.5 g of the crude extract. Their purities were determined to be above 97% by HPLC analysis. Their chemical structures were confirmed by ¹H and ¹³C NMR analysis or HPLC comparison with the reference compounds.  相似文献   

    

Li‐Peng Zhang  Yong Bao  Yun‐Yan Kuang  Fen‐Er Chen 《Helvetica chimica acta》2008,91(11):2057-2061

A six‐step asymmetric total synthesis of (20S)‐camptothecin ( 1 ) has been accomplished in 25% overall yield starting from the known pyridone 3 . The key steps in this synthesis are the chemoselective Ni‐catalyzed hydrogenation of 3‐cyanopyridone 6 to 3‐formylpyridone 7 in AcOH/pyridine/H₂O and the Davis asymmetric hydroxylation of tricyclic lactone 4 utilizing a chiral N‐sulfonyloxaziridine into (4′S)‐tricyclic hydroxylactone 2 .  相似文献   

    

Ying‐Tong Di  Ling‐Li Liu  Chun‐Shun Li  Yu Zhang  Qiang Zhang  Shu‐Zhen Mu  Qian‐Yun Sun  Fu‐Mei Yang  Hai‐Yang Liu  Xiao‐Jiang Hao 《Helvetica chimica acta》2008,91(5):838-843

Eight C₃₀ Daphniphyllum alkaloids, including two new ones, yunnandaphninines F and G ( 1 and 2 , resp.), were isolated from the leaves and stems of Daphniphyllum yunnanense. Their structures were elucidated on the basis of the spectroscopic data.  相似文献   

    

Xing‐Jing Zhang  Yong‐Heng Xing  Jing Han  Mao‐Fa Ge  Shu‐Yun Niu 《无机化学与普通化学杂志》2008,634(10):1765-1769

A series of lanthanide coordination polymers, [Ln^III(mal)(ox)_0.5(H₂O)₂]·2H₂O (Ln = Pr ( 1 ), Nd ( 2 ), and La ( 3 ); H₂mal= maleic acid; H₂ox = oxalic acid), were synthesized firstly by the reaction of Ln^III nitrate salts with maleic anhydrid and oxalic acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. X‐ray diffraction analyses reveal that they are crystallized in orthorhombic space group Fddd. Lanthanide metal center atom (Ln) and its corresponding centrosymmtric atom link through two chelating/bridging bidentate carboxyl groups of maleic acid ligands to form an infinite inorganic rod‐shaped building unit. These rod‐shaped building units were linked to each other through the carbon atoms of the maleate anions on the [110] plane to form lanthanide‐maleic acid layers. The oxalic acid pillared lanthanide‐maleic acid layers with intersected channels by free water molecules consist of a 3D framework structure. The thermogravimetric analyses of 1 – 3 were discussed in detail. The courses of the thermal decomposition of complexes are similar.  相似文献   

    

Chiyoung Park  Jino Lim  Mikyoung Yun  Chulhee Kim 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2008,120(16):3001-3005

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Kim YK  Lee JS  Bi X  Ha HH  Ng SH  Ahn YH  Lee JJ  Wagner BK  Clemons PA  Chang YT 《Angewandte Chemie (International ed. in English)》2011,50(12):2761-2763

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Nam SH  Bae YM  Park YI  Kim JH  Kim HM  Choi JS  Lee KT  Hyeon T  Suh YD 《Angewandte Chemie (International ed. in English)》2011,50(27):6093-6097

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Zining Cui  Li Zhang  Juan Huang  Xinling Yang  Yun Ling 《中国化学》2010,28(7):1257-1266

42 novel diacylhydrazine derivatives containing furan were synthesized by the reaction of 5‐substituted phenyl‐2‐furoyl chloride with substituted benzohydrazide in anhydrous dichloromethane under reflux. Their structures were confirmed by IR, ¹H NMR, MS and elemental analysis. Insecticidal and antitumor activity of these new compounds was evaluated. The preliminary bioassays showed that the target compounds exhibited larvicidal activity to the Mythimna separate, some of them exhibited good or moderate larvicidal activity. At the concentration of 0.1%, compounds I2 , I4 , I5 , and III1 showed 95.0%, 90.0%, 95.0% and 95.0% larvicidal activity to Mythimna separate respectively. Some compounds such as I2 , I4 , I5 and III1 showed the typical IGRs' activity, which could induce the larvae premature, abnormal, and lethal larval molt. Results of anticancer activity indicated that some compounds exhibited potential activity against some human cancer cell lines, for example, I1 and IV showed good activity to the BGC‐823 and the inhibitory rates were 60.86% and 61.94% respectively at 10 µmol/L.  相似文献   

    

Kang‐Zhen Xu  Ji‐Rong Song  Feng‐Qi Zhao  Shu‐Yun Heng  Li Ding  Yao‐Yu Wang  Rong‐Zu Hu 《中国化学会会志》2009,56(3):524-531

A novel high energy material, 1‐amino‐1‐methylamino‐2,2‐dinitroethlyene (AMFOX‐7), was synthesized by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) and methylamine aqueous solution in N‐methyl pyrrolidone at 80°C. The thermal behavior and non‐isothermal decomposition kinetics of AMFOX‐7 were studied with DSC and TG/DTG methods. The kinetic equation of thermal decomposition reaction can be expressed as: $ {rm dalpha /d}T = frac{{10^{21.03}}}{{rm beta}}frac{3}{2}left({1 - {rm alpha}} right)left[{- 1{rm n}left({{rm 1} - {rm alpha}} right)} right]^{frac{1}{3}} exp left({- 2.292 times 10^5 {rm /}RT} right) A novel high energy material, 1‐amino‐1‐methylamino‐2,2‐dinitroethlyene (AMFOX‐7), was synthesized by the reaction of 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) and methylamine aqueous solution in N‐methyl pyrrolidone at 80°C. The thermal behavior and non‐isothermal decomposition kinetics of AMFOX‐7 were studied with DSC and TG/DTG methods. The kinetic equation of thermal decomposition reaction can be expressed as: $ {rm dalpha /d}T = frac{{10^{21.03}}}{{rm beta}}frac{3}{2}left({1 - {rm alpha}} right)left[{- 1{rm n}left({{rm 1} - {rm alpha}} right)} right]^{frac{1}{3}} exp left({- 2.292 times 10^5 {rm /}RT} right) $. The critical temperature of thermal explosion of AMFOX‐7 is 244.89°C. The specific heat capacity of AMFOX‐7 was determined with micro‐DSC method and theoretical calculation method, and the standard molar specific heat capacity is 199.39 J·mol^?1·K^?1 at 298.15 K. Adiabatic time‐to‐explosion of AMFOX‐7 was also calculated to be 215.41 s. AMFOX‐7 has higher thermal stability than FOX‐7.  相似文献   

    

Chein‐I Wu  Jiann‐Wen Huang  Ya‐Lan Wen  Shaw‐Bing Wen  Yun‐Hwei Shen  Mou‐Yung Yeh 《中国化学会会志》2009,56(6):1231-1235

Stable aqueous dispersions of silver (Ag) nanoparticles were prepared by reducing silver nitrate solutions with sodium borohydride (NaBH₄) in the presence of waterborne polyurethane as a stabilizing agent. WPU/Ag nanocomposites were obtained after evaporating water. Transmission electron microscope (TEM) shows nanoscale Ag particles are well dispersed in WPU matrix at a lower concentration, while particles exhibit a little aggregation at a higher concentration. UV‐visible spectra, X‐ray powder diffraction, and energy dispersive X‐ray spectrometer (EDS) confirm the existence of Ag particle in WPU matrix. The WPU/Ag composite films show good antibiotic ability.  相似文献