The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the triclinic system,spac...The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the triclinic system,space group P1 with a=8.0157(8),b=12.5748(13),c=13.3768(14)Å,α=64.770(2),β=75.720(2),γ=89.784(2)°,μ=0.085 mm^(-1),Mr=442.49,V=1174.1(2)Å3,Z=2,Dc=1.252 g/cm^(3),F(000)=468,T=294(2)K,R=0.0603 and wR=0.1498 for 2644 observed reflections with I〉2σ(I).X-ray diffraction analysis reveals that the single crystal contains strong non-classical hydrogen bonds.The preliminary bioassay showed that the title compound exhibits inhibitory activity against the Pseudoperoniospora cubensis and Rhizoctonia solani at the test concentration of 200 mg/L.展开更多
Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-me...Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (【14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 ×10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 ×10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.展开更多
Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amou...Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.展开更多
The title compound （ethyl5-（4-（2-phenylacetamido）phenyl）-lH-pyrazole-3-carboxylate, C20H19N3O3） was synthesized by the reaction of Claisen condensation, cyclization, reduction and acylation. The structure was ch...The title compound （ethyl5-（4-（2-phenylacetamido）phenyl）-lH-pyrazole-3-carboxylate, C20H19N3O3） was synthesized by the reaction of Claisen condensation, cyclization, reduction and acylation. The structure was characterized by X-ray diffraction, MS, NMR and IR. It belongs to the monoclinic system, space group C2/c with a = 22.723（9）, b = 9.324（4）, c = 18.890（8） A, β = 114.259（6）°, V = 3649（3） A^3, Dc = 1.272 Mg·m^3, Z = 8, Mr = 349.38, p = 0.087 mm^-1, F（000） = 1472, the final R = 0.0615 and wR = 0.1643. The biological test shows that the title compound has a moderate acrosin inhibition activity.展开更多
The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined...The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215（9）, b = 8.5311（4）, c = 21.6886（9） A^°, β = 91.607（1）°, V = 3814.0（3）A^°^3, Z = 8, Dc = 1.400 g/cm^3, F（000） = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit.展开更多
The crystal structure of the title compound(E)-ethyl 2-(4-(2,4-dimethoxy benzylide-neamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate(4,C_(24)H_(28)N_(4)O_(7)S,Mr=516.17)was synthesized and determin...The crystal structure of the title compound(E)-ethyl 2-(4-(2,4-dimethoxy benzylide-neamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate(4,C_(24)H_(28)N_(4)O_(7)S,Mr=516.17)was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P2_(1)/n with a=13.162(2),b=8.4506(13),c=22.602(4)Å,β=99.888(3)°,μ=0.183 mm^(-1),V=2476.5(7)Å^(3),Z=4,D_(c)=1.385 g/cm^(3),F(000)=1088,T=110(2)K,R=0.0426 and wR=0.1216 for 3859 observed reflections with I 2σ(Ⅰ).展开更多
The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-ox...The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.展开更多
4-（4,6-Dimethoxyl-pyrimidin-2-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single ...4-（4,6-Dimethoxyl-pyrimidin-2-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at room temperature. The crystal structure was determined by X-ray diffraction analysis. Crystallographic data： C10H14N4O4S, M, = 286.31, monoclinic, space group C2/c with a = 2.5309（3）, b = 0.67682（6）, c = 1.74237（19） nm, β = 114.744（3）°, V= 2.7106（5） nm3, Dc = 1.403 g/cm3, p = 0.225 mm-1, F（000） = 1200, Z= 8, R= 0.0514 and wR= 0.1529.展开更多
A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions o...A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.展开更多
As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-...As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-HPBE is a biocatalyst that efficiently reduces ethyl 2-oxo-4-phenylbutanoate(OPBE)with high R-enantiose-lectivity.This paper proposed a strategy for identifying key residues involved in enantioselectivity control based on per-residue free energy decomposition and sequence conservatism analysis.Using this strategy,4 noncon-servative sites with high energy contribution to binding of OPBE were chosen as engineering targets,generating variant Mu27 with 99%conversion and 98%(R)ee value at substrate loading of up to 500 mmol/L.MD simu-lations suggested the higher stability and formation probability of Mu27-OPBEproR prereaction state as key rea-sons for the excellent R-enantioselectivity of Mu27 towards OPBE.The success in this study provides a viable approach for rational design of alcohol dehydrogenases with high enantioselectivity towards unnatural substrates.展开更多
A series of self-yellowished polymer latexes were pr epared from styrene (St),butyl acrylate (BA) and 2-［4-(4′-nitrophenylazo)p henoxyl］ethyl acrylate (NAPEA) via semi-continuous emulsion polymerization.The influen...A series of self-yellowished polymer latexes were pr epared from styrene (St),butyl acrylate (BA) and 2-［4-(4′-nitrophenylazo)p henoxyl］ethyl acrylate (NAPEA) via semi-continuous emulsion polymerization.The influence of NAPEA on the polymerization,the latex properties and molecule wei ght of copolymer were investigated.The copolymerization of NAPEA with St and BA was preliminary confirmed using thin layer chromatography analysis.Experiments showed that the monomer conversion and the molecular weight of polymer decrease d obviously with the increase of the amount of NAPEA,and the electrolyte resist ance and mechanical stability of latexes were improved by incorporating NAPEA in to polymer chains.展开更多
A new bisxanthone, named bijaponicaxanthone C, was isolated from the whole plant of Hypericum japonicum. The structure was elucidated as 6-[1’’,5’’,6’’-trihydroxy-2’’’-(β-hydroxy-β- methylethyl)-2’’’,3...A new bisxanthone, named bijaponicaxanthone C, was isolated from the whole plant of Hypericum japonicum. The structure was elucidated as 6-[1’’,5’’,6’’-trihydroxy-2’’’-(β-hydroxy-β- methylethyl)-2’’’,3’’’-dihydrofuran(5’’’,4’’’,3’’,4’’)xanthone-3’’’-oxyl]-1,3,5-trihydroxy-4-isoprenylxant- hone (1) on the basis of the spectral and chemical evidences.展开更多
Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl）ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-（4＂-hydroxy-3＂,5＂- named isatidifoliumindolinones A-D （1-4）, were isolated from an...Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl）ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-（4＂-hydroxy-3＂,5＂- named isatidifoliumindolinones A-D （1-4）, were isolated from an aqueous extract of lsatis indigotica leaves （da qing ye）. Their structures including absolute configurations were determined by spectroscopic data analysis combined with comparison of their experimental CD and calculated ECD spectra. Validity of the ECD spectra calculation to assign the absolute configurations is discussed. Plausible biosynthetic pathways of 1-4 are proposed. Stereochemistry-dependent activity against LPS-induced NO production in BY2 cells was observed, and among the stereoisomers compound 4 is most active.展开更多
基金supported by the Science Foundation of the Southern Medical University for New Excellent Talents(No.B1000374)
文摘The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the triclinic system,space group P1 with a=8.0157(8),b=12.5748(13),c=13.3768(14)Å,α=64.770(2),β=75.720(2),γ=89.784(2)°,μ=0.085 mm^(-1),Mr=442.49,V=1174.1(2)Å3,Z=2,Dc=1.252 g/cm^(3),F(000)=468,T=294(2)K,R=0.0603 and wR=0.1498 for 2644 observed reflections with I〉2σ(I).X-ray diffraction analysis reveals that the single crystal contains strong non-classical hydrogen bonds.The preliminary bioassay showed that the title compound exhibits inhibitory activity against the Pseudoperoniospora cubensis and Rhizoctonia solani at the test concentration of 200 mg/L.
文摘Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (【14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 ×10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 ×10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.
文摘Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.
基金supported by the Science and technology support program of Jiangsu Province (2010, BE2010682)
文摘The title compound （ethyl5-（4-（2-phenylacetamido）phenyl）-lH-pyrazole-3-carboxylate, C20H19N3O3） was synthesized by the reaction of Claisen condensation, cyclization, reduction and acylation. The structure was characterized by X-ray diffraction, MS, NMR and IR. It belongs to the monoclinic system, space group C2/c with a = 22.723（9）, b = 9.324（4）, c = 18.890（8） A, β = 114.259（6）°, V = 3649（3） A^3, Dc = 1.272 Mg·m^3, Z = 8, Mr = 349.38, p = 0.087 mm^-1, F（000） = 1472, the final R = 0.0615 and wR = 0.1643. The biological test shows that the title compound has a moderate acrosin inhibition activity.
基金supported by the Natural Science Foundation of Hubei Province (2006ABB016)Key Science Research Project of Hubei Provincial Department of Education (No.D200724001) the Science Research Project of Yunyang Medical College (No. 2006QDJ16)
文摘The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215（9）, b = 8.5311（4）, c = 21.6886（9） A^°, β = 91.607（1）°, V = 3814.0（3）A^°^3, Z = 8, Dc = 1.400 g/cm^3, F（000） = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit.
基金supported by the Science Foundation of the Southern Medical University for New Excellent Talents(No.B1000374)the Natural Science Foundation of Guangdong Province(No.10451051501004725)
文摘The crystal structure of the title compound(E)-ethyl 2-(4-(2,4-dimethoxy benzylide-neamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate(4,C_(24)H_(28)N_(4)O_(7)S,Mr=516.17)was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P2_(1)/n with a=13.162(2),b=8.4506(13),c=22.602(4)Å,β=99.888(3)°,μ=0.183 mm^(-1),V=2476.5(7)Å^(3),Z=4,D_(c)=1.385 g/cm^(3),F(000)=1088,T=110(2)K,R=0.0426 and wR=0.1216 for 3859 observed reflections with I 2σ(Ⅰ).
基金Supported by the National Natural Science Foundation of China (20872033, 20575019)Natural Science Foundation of Hunan Province (07JJ1003)+1 种基金Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) (KLCBTCMR2008-14)Scientific Research Fund of Science and Technology Department of Hunan Province (No. 2006GK3067)
文摘The title compound ethyl 2-（6-（1,3-dioxo-4,5,6,7-tetrahydro-lH-isoindol-2（3H）- yl）-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate 3 was synthesized by the reaction of ethyl 2-（6-amino-7-fluoro-3-oxo-2H-benzo[b][1,4]oxazin-4（3H）-yl） butanoate with 4,5,6,7- tetraydrophthalic anhydride, and its structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2 1/n with a = 9.3469（2）, b = 16.7715（5）, c = 13.7153（4） A, β= 104.9680（10）°, μ = 0.107 mm^-1, Mr = 430.42, V= 2077.08（10） ,A3, Z= 4, Dc = 1.376 g/cm3, F（000） = 904, T= 296（2） K, R = 0.0508 and wR = 0.1478.
基金supported by the National Natural Science Foundation of China (20571060)Natural Science Foundation of Shaanxi Province (2007B08)Education Committee of Shaanxi Province (05JK294)
文摘4-（4,6-Dimethoxyl-pyrimidin-2-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at room temperature. The crystal structure was determined by X-ray diffraction analysis. Crystallographic data： C10H14N4O4S, M, = 286.31, monoclinic, space group C2/c with a = 2.5309（3）, b = 0.67682（6）, c = 1.74237（19） nm, β = 114.744（3）°, V= 2.7106（5） nm3, Dc = 1.403 g/cm3, p = 0.225 mm-1, F（000） = 1200, Z= 8, R= 0.0514 and wR= 0.1529.
文摘A concise and efficient method for the synthesis of novel 9,10-imethoxybenzo[6,7]oxepino[3,4-b]quinolin13(6H)-one and its derivatives 7a-p has been developed via the intramolecular Friedel-Crafts acylation reactions of 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylic acids 6a-p with polyphosphoric acid (PPA) as catalyst and solvent under mild conditions. The key intermediates 6a-p were prepared through the in situ formation of ethyl 6,7-dimethoxy-2-(phenoxymethyl)quinoline-3-carboxylates 5a-p followed by hydrolysis with aqueous ethanolic sodium hydroxide solution. The novel synthetic method has the advantages of good yields, easy work-up, and environmentally friendly character, which may provide a novel highly efficient process for making quinoline and related azaheterocycle libraries.
基金This study is financially supported by the National Key Research and Development Program of China(No.2018YFA0901800 to H.Yu and L.Ye)Zhejiang Provincial Natural Science Foundation of China(No.LY18B060001 to L.Ye and No.LZ20B060002 to H.Yu)Natural Science Foundation of China(No.21776244 to H.Yu).We are grateful to the constructive suggestions from academician Fen-Er Chen(Department of Chemistry,Fudan University,Shanghai,China)and the support of Discovery Studio software from Fuzhou University platform.
文摘As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-HPBE is a biocatalyst that efficiently reduces ethyl 2-oxo-4-phenylbutanoate(OPBE)with high R-enantiose-lectivity.This paper proposed a strategy for identifying key residues involved in enantioselectivity control based on per-residue free energy decomposition and sequence conservatism analysis.Using this strategy,4 noncon-servative sites with high energy contribution to binding of OPBE were chosen as engineering targets,generating variant Mu27 with 99%conversion and 98%(R)ee value at substrate loading of up to 500 mmol/L.MD simu-lations suggested the higher stability and formation probability of Mu27-OPBEproR prereaction state as key rea-sons for the excellent R-enantioselectivity of Mu27 towards OPBE.The success in this study provides a viable approach for rational design of alcohol dehydrogenases with high enantioselectivity towards unnatural substrates.
文摘A series of self-yellowished polymer latexes were pr epared from styrene (St),butyl acrylate (BA) and 2-［4-(4′-nitrophenylazo)p henoxyl］ethyl acrylate (NAPEA) via semi-continuous emulsion polymerization.The influence of NAPEA on the polymerization,the latex properties and molecule wei ght of copolymer were investigated.The copolymerization of NAPEA with St and BA was preliminary confirmed using thin layer chromatography analysis.Experiments showed that the monomer conversion and the molecular weight of polymer decrease d obviously with the increase of the amount of NAPEA,and the electrolyte resist ance and mechanical stability of latexes were improved by incorporating NAPEA in to polymer chains.
基金supported by the National 863 program of China(2003AA2Z3507)Science and Technology Developping Foundation of Shanghai(02DZ19147,01DJ19010)
文摘A new bisxanthone, named bijaponicaxanthone C, was isolated from the whole plant of Hypericum japonicum. The structure was elucidated as 6-[1’’,5’’,6’’-trihydroxy-2’’’-(β-hydroxy-β- methylethyl)-2’’’,3’’’-dihydrofuran(5’’’,4’’’,3’’,4’’)xanthone-3’’’-oxyl]-1,3,5-trihydroxy-4-isoprenylxant- hone (1) on the basis of the spectral and chemical evidences.
基金Financial support from the National Natural Science Foundation of China (NNSFCNos.81630094,81373287,and 30825044)
文摘Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl）ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-（4＂-hydroxy-3＂,5＂- named isatidifoliumindolinones A-D （1-4）, were isolated from an aqueous extract of lsatis indigotica leaves （da qing ye）. Their structures including absolute configurations were determined by spectroscopic data analysis combined with comparison of their experimental CD and calculated ECD spectra. Validity of the ECD spectra calculation to assign the absolute configurations is discussed. Plausible biosynthetic pathways of 1-4 are proposed. Stereochemistry-dependent activity against LPS-induced NO production in BY2 cells was observed, and among the stereoisomers compound 4 is most active.
