Lotus(Nelumbo nucifera),an ancient aquatic plant,possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids(BIAs).However,only few genes and enzymes involved in BIA biosy...Lotus(Nelumbo nucifera),an ancient aquatic plant,possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids(BIAs).However,only few genes and enzymes involved in BIA biosynthesis in N.nucifera have been isolated and characterized.In the present study we identified the regiopromiscuity of an O-methyltransferase,designated NnOMT6,isolated from N.nucifera;NnOMT6 was found to catalyze the methylation of monobenzylisoquinoline 6-O/7-O,aporphine skeleton 6-O,phenylpropanoid 3-O,and protoberberine 2-O.We further probed the key residues affecting NnOMT6 activity via molecular docking and molecular dynamics simulation.Verification using site-directed mutagenesis revealed that residues D316,N130,L135,N176A,D269,and E328 were critical for BIA O-methyltransferase activities;furthermore,N323A,a mutant of NnOMT6,demonstrated a substantial increase in catalytic efficiency for BIAs and a broader acceptor scope compared with wild-type NnOMT6.To the best of our knowledge,this is the first study to report the O-methyltransferase activity of an aporphine skeleton without benzyl moiety substitutions in N.nucifera.The study findings provide biocatalysts for the semisynthesis of related medical compounds and give insights into protein engineering to strengthen O-methyltransferase activity in plants.展开更多
The selective aerobic oxidation of benzyl alcohol to benzaldehyde has attracted considerable attention because benzaldehyde is a high value-added product. The rate of this typical gas–liquid reaction is significantly...The selective aerobic oxidation of benzyl alcohol to benzaldehyde has attracted considerable attention because benzaldehyde is a high value-added product. The rate of this typical gas–liquid reaction is significantly affected by mass transfer. In this study, CoTPP-mediated(CoTPP: cobalt(II) mesotetraphenylporphyrin) selective benzyl alcohol oxidation with oxygen was conducted in a membrane microchannel(MMC) reactor and a bubble column(BC) reactor, respectively. We observed that 83% benzyl alcohol was converted within 6.5 min in the MMC reactor, but only less than 10% benzyl alcohol was converted in the BC reactor. Hydrodynamic characteristics and gas–liquid mass transfer performances were compared for the MMC and BC reactors. The MMC reactor was assumed to be a plug flow reactor,and the dimensionless variance was 0.29. Compared to the BC reactor, the gas–liquid mass transfer was intensified significantly in MMC reactor. It could be ascribed to the high gas holdup(2.9 times higher than that of BC reactor), liquid film mass transfer coefficient(8.2 times higher than that of BC reactor), and mass transfer coefficient per unit interfacial area(3.8 times higher than that of BC reactor). Moreover,the Hatta number for the MMC reactor reached up to 0.61, which was about 15 times higher than that of the BC reactor. The computational fluid dynamics calculations for mass fractions in both liquid and gas phases were consistent with the experimental data.展开更多
Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was ...Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, plane MFI structured titanosilicate (TS-1) and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] (TPA), dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P+aq] (DMAA), sodium tungstate hydrated purified [Na12WO4.2H2O] (STH)] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.展开更多
NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemosele...NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.展开更多
A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additiona...A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additionally, the HfO2 can be re-used after the reaction. ?2009 Xin Qin Gao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic ac...In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic activity not only for electron-rich aromatic compounds, but also for electron-poor aromatic compounds. Under identical conditions, the self-benzylation of benzyl chloride, and dibenzylation and/or multi-benzylation of aromatic compounds were negligible.展开更多
A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According ...A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.展开更多
o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hyd...o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hydride transfer mechanism.展开更多
Objective:To determine the content of benzyl glueosinolate(BG) in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performe...Objective:To determine the content of benzyl glueosinolate(BG) in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C<sub>18</sub> column at the wavelength of 214 nm with 0.1%trifluoroacelic acid(TFA) aqueous solution(A) and 0.1%TFA acelonilrile(B) as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale(BITC) againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC<sub>50</sub> was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.展开更多
Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolu...Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.展开更多
Lotus predominantly accumulates benzylisoquinoline alkaloids(BIAs),but their biosynthesis and regulation remain unclear.Here,we investigated structural and regulatory genes involved in BIA accumulation in lotus.Two cl...Lotus predominantly accumulates benzylisoquinoline alkaloids(BIAs),but their biosynthesis and regulation remain unclear.Here,we investigated structural and regulatory genes involved in BIA accumulation in lotus.Two clustered CYP80 genes were identified to be responsible for the biosynthesis of bis-BIAs and aporphine-type BIAs,respectively,and their tissue-specific expression causes divergence in alkaloid component between leaf and embryo.In contrast with the common(S)-reticuline precursor for most BIAs,aporphine alkaloids in lotus leaf may result from the(S)-N-methylcoclaurine precursor.Structural diversity of BIA alkaloids in the leaf is attributed to enzymatic modifications,including intramolecular C–C phenol coupling on ring A and methylation and demethylation at certain positions.Additionally,most BIA biosynthetic pathway genes show higher levels of expression in the leaf of high-BIA cultivar compared with low-BIA cultivar,suggesting transcriptional regulation of BIA accumulation in lotus.Five transcription factors,including three MYBs,one ethylene-responsive factor,and one basic helix–loop–helix(bHLH),were identified to be candidate regulators of BIA biosynthesis in lotus.Our study reveals a BIA biosynthetic pathway and its transcriptional regulation in lotus,which will enable a deeper understanding of BIA biosynthesis in plants.展开更多
A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction...A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, in situ laser Raman spectroscopy, UV-Vis diffused reflectance spectroscopy, scanning electron microscopy, and temperature-programmed desorption of NH3 techniques. Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol. The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity. The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support. In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures. The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.展开更多
Two new benzyl dihydroflavones phelligrins A and B were isolated from the fruit body of Phellinus igniarius. Their structrues were identified as 5, 7, 4-trihydroxy-6-O-hydroxybenzyl -dihydroflavone and 5, 7, 4-trihyd...Two new benzyl dihydroflavones phelligrins A and B were isolated from the fruit body of Phellinus igniarius. Their structrues were identified as 5, 7, 4-trihydroxy-6-O-hydroxybenzyl -dihydroflavone and 5, 7, 4-trihydroxy-8-O-hydroxybenzyldihydroflavone, respectively, by means of spectral methods.展开更多
Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic ac...Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.展开更多
Opium poppy(Papaver somniferum)is a source of morphine,codeine,and semisynthetic derivatives,including oxycodone and naltrexone.Here,we report the de novo assembly and genomic analysis of P.somniferum traditional land...Opium poppy(Papaver somniferum)is a source of morphine,codeine,and semisynthetic derivatives,including oxycodone and naltrexone.Here,we report the de novo assembly and genomic analysis of P.somniferum traditional landrace‘Chinese Herbal Medicine’.Variations between the 2.62 Gb CHM genome and that of the previously sequenced high noscapine 1(HN1)variety were also explored.Among 79,668 protein-coding genes,we functionally annotated 88.9%,compared to 68.8%reported in the HN1 genome.Gene family and 4DTv comparative analyses with three other Papaveraceae species revealed that opium poppy underwent two whole-genome duplication(WGD)events.The first of these,in ancestral Ranunculales,expanded gene families related to characteristic secondary metabolite production and disease resistance.The more recent species-specific WGD mediated by transposable elements resulted in massive genome expansion.Genes carrying structural variations and large-effect variants associated with agronomically different phenotypes between CHM and HN1 that were identified through our transcriptomic comparison of multiple organs and developmental stages can enable the development of new varieties.These genomic and transcriptomic analyses will provide a valuable resource that informs future basic and agricultural studies of the opium poppy.展开更多
Heterogeneous photocatalytic system are widely applied to degrade organic pollutants or converse into high value-added chemicals. Both environmental and energy aspects should be considered to improve these chemical pr...Heterogeneous photocatalytic system are widely applied to degrade organic pollutants or converse into high value-added chemicals. Both environmental and energy aspects should be considered to improve these chemical processes, favoring reaction conditions that involve room temperature and ambient O2 pressure. In the present work, hollow titanium dioxide nanospheres were fabricated via template-free method. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation of benzyl alcohol to benzaldehyde with visible light under atmospheric pressure at room temperature. The designed hollow structure(2%Pt–TiO2–5) not only exhibited a very high surface area,but also promoted photonic behavior and multiple light scattering, which as an efficient photocatalyst performed moderate conversion(about 20%) and high selectivity(> 99%) for oxidation of benzyl alcohol to benzaldehyde at room temperature with visible light in solvent of toluene.This work suggests that both hollow structure and Pt nanoparticles have great potential for execution of oxidative transformations under visible light.展开更多
Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr+Cl04- or PhAcr+Cl04- as photocatalysts under visible light irradiation at room temperature.
Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric ...Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.展开更多
Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetrapbenylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed. The catalyst has ...Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetrapbenylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.展开更多
Fe_3O_4-PVDF membranes were prepared by blending of magnetic Fe_3O_4 powders with polyvinylidene fluoride to investigate whether those were usable or not in catalytic membrane reactors. Filtration performances and cat...Fe_3O_4-PVDF membranes were prepared by blending of magnetic Fe_3O_4 powders with polyvinylidene fluoride to investigate whether those were usable or not in catalytic membrane reactors. Filtration performances and catalytic activity of membranes in microwave conditions were measured in separate processes. Composite Fe_3O_4-PVDF membranes were characterized by TG-DTA, FTIR, XRD, SEM and contact angle techniques.Disappearing of α-phases at PVDF was observed with increasing amount of additives from XRD diffraction patterns. Decomposition of polymer fastened due to catalytic effect of Fe_3O_4. Finger-like structures and large number of small pores were observed at the SEM images. Those provided effective transportation of substrate among the active sites of catalyst. At the experiments conducted in batch reactor, 51%, 77%, 66% and 63% benzyl alcohol conversion were recorded for 2%, 4%, 6% and 8% Fe_3O_4-PVDF composite pieces respectively. Catalyst were separated magnetically and reused several times. On the other hand Fe_3O_4 blended PVDF membranes provided improved flux and BSA rejection compared with performance of bare PVDF membrane; 41.6% BSA rejection was obtained with 4% Fe_3O_4-PVDF whereas it was only 6.7% for PVDF. Fe_3O_4-PVDF composites performed high activity for the benzyl alcohol oxidation in batch reactor and also better filtration at filtration cell. These results promise to obtain practical and low cost membrane material for catalytic reactors usable in microwave support to get fast results.展开更多
基金supported by the National Natural Science Foundation of China(32170388)the Scientific and Technological Innovation project of China Academy of Chinese Medical Sciences(CACMS Innovation Fund CI2021A04108,CI2021A04515)the Fundamental Research Funds for the Central Public Welfare Research Institutes of China(ZZ13-YQ-057,ZXKT21006)。
文摘Lotus(Nelumbo nucifera),an ancient aquatic plant,possesses a unique pharmacological activity that is primarily contributed by benzylisoquinoline alkaloids(BIAs).However,only few genes and enzymes involved in BIA biosynthesis in N.nucifera have been isolated and characterized.In the present study we identified the regiopromiscuity of an O-methyltransferase,designated NnOMT6,isolated from N.nucifera;NnOMT6 was found to catalyze the methylation of monobenzylisoquinoline 6-O/7-O,aporphine skeleton 6-O,phenylpropanoid 3-O,and protoberberine 2-O.We further probed the key residues affecting NnOMT6 activity via molecular docking and molecular dynamics simulation.Verification using site-directed mutagenesis revealed that residues D316,N130,L135,N176A,D269,and E328 were critical for BIA O-methyltransferase activities;furthermore,N323A,a mutant of NnOMT6,demonstrated a substantial increase in catalytic efficiency for BIAs and a broader acceptor scope compared with wild-type NnOMT6.To the best of our knowledge,this is the first study to report the O-methyltransferase activity of an aporphine skeleton without benzyl moiety substitutions in N.nucifera.The study findings provide biocatalysts for the semisynthesis of related medical compounds and give insights into protein engineering to strengthen O-methyltransferase activity in plants.
基金financially supported by the National Key Research and Development Program of China (2020YFA0210900)the National Natural Science Foundation of China (21938001 and 21878344)+1 种基金Guangdong Provincial Key Research and Development Programme (2019B110206002)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01C102)。
文摘The selective aerobic oxidation of benzyl alcohol to benzaldehyde has attracted considerable attention because benzaldehyde is a high value-added product. The rate of this typical gas–liquid reaction is significantly affected by mass transfer. In this study, CoTPP-mediated(CoTPP: cobalt(II) mesotetraphenylporphyrin) selective benzyl alcohol oxidation with oxygen was conducted in a membrane microchannel(MMC) reactor and a bubble column(BC) reactor, respectively. We observed that 83% benzyl alcohol was converted within 6.5 min in the MMC reactor, but only less than 10% benzyl alcohol was converted in the BC reactor. Hydrodynamic characteristics and gas–liquid mass transfer performances were compared for the MMC and BC reactors. The MMC reactor was assumed to be a plug flow reactor,and the dimensionless variance was 0.29. Compared to the BC reactor, the gas–liquid mass transfer was intensified significantly in MMC reactor. It could be ascribed to the high gas holdup(2.9 times higher than that of BC reactor), liquid film mass transfer coefficient(8.2 times higher than that of BC reactor), and mass transfer coefficient per unit interfacial area(3.8 times higher than that of BC reactor). Moreover,the Hatta number for the MMC reactor reached up to 0.61, which was about 15 times higher than that of the BC reactor. The computational fluid dynamics calculations for mass fractions in both liquid and gas phases were consistent with the experimental data.
文摘Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, plane MFI structured titanosilicate (TS-1) and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] (TPA), dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P+aq] (DMAA), sodium tungstate hydrated purified [Na12WO4.2H2O] (STH)] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.
文摘NaBH<sub>4</sub>, CH<sub>3</sub>CO<sub>2</sub>H, Pd/C has been described as an effective reagent system to hydrogenate alkenes. Here, we show that the hydrogenation occurs chemoselectively, making it possible to hydrogenate alkenes under Pd/C catalysis with hydrogen created in situ without O- or N-debenzylation.
文摘A highly efficient benzylation of arenes and heteroarenes catalyzed by HfCl4/HfO2 has been developed. Broad scope of benzylation reagents have been used in this process with high yields under mild condition. Additionally, the HfO2 can be re-used after the reaction. ?2009 Xin Qin Gao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘In the presence of Nafion/SiO2 nanocomposite catalyst, the benzylation of aromatic compounds with benzyl chloride proceeded to afford diphenylmethane derivatives in high yields. The catalyst showed high catalytic activity not only for electron-rich aromatic compounds, but also for electron-poor aromatic compounds. Under identical conditions, the self-benzylation of benzyl chloride, and dibenzylation and/or multi-benzylation of aromatic compounds were negligible.
基金This work was supported by the Major State Basic Research Program of China (No. G1999064704).
文摘A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.
文摘o-Bromomethylbenzylidenemalononitrile 4 is reduced by 1-benzyl-1,4-dihydronicotinamide (BNAH, 1) to give 2,2-indanedicarbonitrile 6 and p-bromomethylbenzylidenemalononitrile 5 is reduced by BNAH to give 7 and 8 by hydride transfer mechanism.
基金Supported by National Key Technologies R & D Program of China (2009BADA2B02-04)Natural Science Fund of Hainan Province(No.309042)Natural Science Fund of China(No.31171822)
文摘Objective:To determine the content of benzyl glueosinolate(BG) in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C<sub>18</sub> column at the wavelength of 214 nm with 0.1%trifluoroacelic acid(TFA) aqueous solution(A) and 0.1%TFA acelonilrile(B) as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale(BITC) againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC<sub>50</sub> was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.
基金financially supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(grant nos.51772285,21473170)the Fundamental Research Funds for the Central Universities
文摘Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.
基金This project was supported by funds received from the National Natural Science Foundation of China(Grants 31450110420 and 31272195)the Overseas Construction Plan for Science and Education Base,China-Africa Center for Research and Education,Chinese Academy of Sciences(Grant No.SAJC201327).
文摘Lotus predominantly accumulates benzylisoquinoline alkaloids(BIAs),but their biosynthesis and regulation remain unclear.Here,we investigated structural and regulatory genes involved in BIA accumulation in lotus.Two clustered CYP80 genes were identified to be responsible for the biosynthesis of bis-BIAs and aporphine-type BIAs,respectively,and their tissue-specific expression causes divergence in alkaloid component between leaf and embryo.In contrast with the common(S)-reticuline precursor for most BIAs,aporphine alkaloids in lotus leaf may result from the(S)-N-methylcoclaurine precursor.Structural diversity of BIA alkaloids in the leaf is attributed to enzymatic modifications,including intramolecular C–C phenol coupling on ring A and methylation and demethylation at certain positions.Additionally,most BIA biosynthetic pathway genes show higher levels of expression in the leaf of high-BIA cultivar compared with low-BIA cultivar,suggesting transcriptional regulation of BIA accumulation in lotus.Five transcription factors,including three MYBs,one ethylene-responsive factor,and one basic helix–loop–helix(bHLH),were identified to be candidate regulators of BIA biosynthesis in lotus.Our study reveals a BIA biosynthetic pathway and its transcriptional regulation in lotus,which will enable a deeper understanding of BIA biosynthesis in plants.
基金supported by the Department of Science & Technology, New Delhi under SERC scheme, DST No. SR/S1/PC-40/2006
文摘A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, in situ laser Raman spectroscopy, UV-Vis diffused reflectance spectroscopy, scanning electron microscopy, and temperature-programmed desorption of NH3 techniques. Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol. The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity. The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support. In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures. The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.
基金The authors are grateful to professor Ablez zeper Institute of Materia Medica,Chinese Academy of Medical Sciences,for mass spectra measurements,and financial support from National“863”program of China(Grant No.2001AA234021).
文摘Two new benzyl dihydroflavones phelligrins A and B were isolated from the fruit body of Phellinus igniarius. Their structrues were identified as 5, 7, 4-trihydroxy-6-O-hydroxybenzyl -dihydroflavone and 5, 7, 4-trihydroxy-8-O-hydroxybenzyldihydroflavone, respectively, by means of spectral methods.
基金the support of Natural Science Foundation of China (51804238, 51904214)the Open Foundation of State Key Laboratory of Mineral Processing, BGRIMM Technology (No. BGRIMM-KJSKL-2021-22)the Fundamental Research Funds for the Central Universities (2021IVA110, 2021IVA039)。
文摘Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.
基金the National Science Foundation of China(Grant 81671876)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Grant 2016JB024)。
文摘Opium poppy(Papaver somniferum)is a source of morphine,codeine,and semisynthetic derivatives,including oxycodone and naltrexone.Here,we report the de novo assembly and genomic analysis of P.somniferum traditional landrace‘Chinese Herbal Medicine’.Variations between the 2.62 Gb CHM genome and that of the previously sequenced high noscapine 1(HN1)variety were also explored.Among 79,668 protein-coding genes,we functionally annotated 88.9%,compared to 68.8%reported in the HN1 genome.Gene family and 4DTv comparative analyses with three other Papaveraceae species revealed that opium poppy underwent two whole-genome duplication(WGD)events.The first of these,in ancestral Ranunculales,expanded gene families related to characteristic secondary metabolite production and disease resistance.The more recent species-specific WGD mediated by transposable elements resulted in massive genome expansion.Genes carrying structural variations and large-effect variants associated with agronomically different phenotypes between CHM and HN1 that were identified through our transcriptomic comparison of multiple organs and developmental stages can enable the development of new varieties.These genomic and transcriptomic analyses will provide a valuable resource that informs future basic and agricultural studies of the opium poppy.
基金support provided by the National Key R&D Program of China (No. 2017YFB0602804)the National Natural Science Foundation of China (No. 21878164)+1 种基金the National Key Technology Support Program of China (No. 2014BAC10B01)the Key Scientific and Technological Project of Shanxi Province (No. MH2014-10)
文摘Heterogeneous photocatalytic system are widely applied to degrade organic pollutants or converse into high value-added chemicals. Both environmental and energy aspects should be considered to improve these chemical processes, favoring reaction conditions that involve room temperature and ambient O2 pressure. In the present work, hollow titanium dioxide nanospheres were fabricated via template-free method. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation of benzyl alcohol to benzaldehyde with visible light under atmospheric pressure at room temperature. The designed hollow structure(2%Pt–TiO2–5) not only exhibited a very high surface area,but also promoted photonic behavior and multiple light scattering, which as an efficient photocatalyst performed moderate conversion(about 20%) and high selectivity(> 99%) for oxidation of benzyl alcohol to benzaldehyde at room temperature with visible light in solvent of toluene.This work suggests that both hollow structure and Pt nanoparticles have great potential for execution of oxidative transformations under visible light.
文摘Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr+Cl04- or PhAcr+Cl04- as photocatalysts under visible light irradiation at room temperature.
基金This project was financially supported by the National Natural Science Foundation of China(Approved No.29775006)
文摘Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.
基金The authors thank the National Natural Science Foundation of China (No. 20576045)the Program for New Century Excellent Talents in University (NCET) for the financial support.
文摘Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetrapbenylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.
文摘Fe_3O_4-PVDF membranes were prepared by blending of magnetic Fe_3O_4 powders with polyvinylidene fluoride to investigate whether those were usable or not in catalytic membrane reactors. Filtration performances and catalytic activity of membranes in microwave conditions were measured in separate processes. Composite Fe_3O_4-PVDF membranes were characterized by TG-DTA, FTIR, XRD, SEM and contact angle techniques.Disappearing of α-phases at PVDF was observed with increasing amount of additives from XRD diffraction patterns. Decomposition of polymer fastened due to catalytic effect of Fe_3O_4. Finger-like structures and large number of small pores were observed at the SEM images. Those provided effective transportation of substrate among the active sites of catalyst. At the experiments conducted in batch reactor, 51%, 77%, 66% and 63% benzyl alcohol conversion were recorded for 2%, 4%, 6% and 8% Fe_3O_4-PVDF composite pieces respectively. Catalyst were separated magnetically and reused several times. On the other hand Fe_3O_4 blended PVDF membranes provided improved flux and BSA rejection compared with performance of bare PVDF membrane; 41.6% BSA rejection was obtained with 4% Fe_3O_4-PVDF whereas it was only 6.7% for PVDF. Fe_3O_4-PVDF composites performed high activity for the benzyl alcohol oxidation in batch reactor and also better filtration at filtration cell. These results promise to obtain practical and low cost membrane material for catalytic reactors usable in microwave support to get fast results.