A variety of aldehydes were converted into acylals in excellent yields with acetic anhydride in the presence of a catalytic amount of tin (IV) chloride supported on silica gel at room temperature.
An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in hi...An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in high yields (86% - 97%) at room temperature under solvent-free conditions. Deprotection of the resulting acylals has also been attained by using the same catalysts under microwave irradiation. This method consistently has advantage of excellent yields (82% - 96%) and a short reaction time (3 - 4 min).展开更多
A facile, rapid and solvent-flee method for the conversion of acids and dihalomethane to the corresponding methylene diesters （acylals） using microwave as activators or assistor, is reported. This method is particul...A facile, rapid and solvent-flee method for the conversion of acids and dihalomethane to the corresponding methylene diesters （acylals） using microwave as activators or assistor, is reported. This method is particularly powerful for the diesterification of carboxylic acids, which afford methylene diesters in good to excellent yields （up to 〉99%）. When the intermediate is trapped, a ＂double successive SN2 reactions＂ mechanism is proved.展开更多
MWCNTs-C-PO3H2has been used as an efficient,heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.A wide range of aldehydes was studied and c...MWCNTs-C-PO3H2has been used as an efficient,heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.A wide range of aldehydes was studied and corresponding products were obtained in good to excellent yields in short reaction times.Nanocatalyst can be easily recovered by centrifuge and reused for subsequent reactions for at least five times without deterioration in catalytic activity.The major advantages of the present method are high yields,short reaction time,recyclable catalyst and solvent-free reaction conditions at room temperature.展开更多
A method for the rapid reduction of acyl chlorides to aldehydes was developed using pinacolborane(HBpin)as the reducing agent.The method exhibits excellent generality for both aromatic and aliphatic substrates,affordi...A method for the rapid reduction of acyl chlorides to aldehydes was developed using pinacolborane(HBpin)as the reducing agent.The method exhibits excellent generality for both aromatic and aliphatic substrates,affording aldehydes in isolated yields of up to 88%with broad functional group tolerance,including cyano,halogen,alkenyl,ketone,and ester groups.Moreover,the method enables gram-scale aldehyde synthesis and shows high efficiency in reducing in situ generated acyl chlorides,thereby enhancing its synthetic practicality.展开更多
Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehyde...Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehydes via acyl radical intermediates is reported.This method exhibits exceptional functional group tolerance and enables late-stage diversification of peptides and carbonyl-group derivatization.Mechanistic studies confirm a radical-based pathway,while applications in peptide modification highlight its utility in bioorganic chemistry.展开更多
Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k...Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.展开更多
Indole[2,1-α]isoquinolines are an important class of bioactive molecules and show good antibacterial activity.In the present study,an efficient copper(I)-catalyzed acylation/cyclization has been developed for the con...Indole[2,1-α]isoquinolines are an important class of bioactive molecules and show good antibacterial activity.In the present study,an efficient copper(I)-catalyzed acylation/cyclization has been developed for the construction of indolo[2,1-α]isoquinoline derivatives by utilizing 2-aryl-N-acryloyl indole and benzohydrazide as reactants in the presence of CuI as catalyst and tert-butyl hydroperoxide as oxidant.The present protocol exhibits good functional group tolerance,and a series of acylated indole[2,1-α]isoquinolines were synthesized in moderate to good yields.Radical trapping experiments indicated that the reaction may involve a radical process.展开更多
Highly toxic phosgene,diethyl chlorophosphate(DCP)and volatile acyl chlorides endanger our life and public security.To achieve facile sensing and discrimination of multiple target analytes,herein,we presented a single...Highly toxic phosgene,diethyl chlorophosphate(DCP)and volatile acyl chlorides endanger our life and public security.To achieve facile sensing and discrimination of multiple target analytes,herein,we presented a single fluorescent probe(BDP-CHD)for high-throughput screening of phosgene,DCP and volatile acyl chlorides.The probe underwent a covalent cascade reaction with phosgene to form boron dipyrromethene(BODIPY)with bright green fluorescence.By contrast,DCP,diphosgene and acyl chlorides can covalently assembled with the probe,giving rise to strong blue fluorescence.The probe has demonstrated high-throughput detection capability,high sensitivity,fast response(within 3 s)and parts per trillion(ppt)level detection limit.Furthermore,a portable platform based on BDP-CHD was constructed,which has achieved high-throughput discrimination of 16 analytes through linear discriminant analysis(LDA).Moreover,a smartphone adaptable RGB recognition pattern was established for the quantitative detection of multi-analytes.Therefore,this portable fluorescence sensing platform can serve as a versatile tool for rapid and high-throughput detection of toxic phosgene,DCP and volatile acyl chlorides.The proposed“one for more”strategy simplifies multi-target discrimination procedures and holds great promise for various sensing applications.展开更多
Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)...Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)[Co(CO)_(4)]^(-)catalysts.However,the decomposition of[Co(CO)_(4)]^(-)species at temperatures exceeding 80℃presents a hurdle for the development of commercially viable processes under high-temperature reaction conditions to reduce reaction time.Drawing insights from stable{(acyl)Co(CO)n}intermediates involved in historical HCo(CO)_(4)-catalyzed hydroformylation processes,we sought to the high-temperature catalytic activity of epoxide ring-expansion carbonylation.The developed catalyst system,[(acetyl)Co(CO)_(2)dppp]and[(TPP)CrCl],exhibited exceptional catalytic performance with an unprecedented initial turnover frequency of 4700 h^(-1)at 100℃and a turnover numbers of 93000.Notably,the catalyst displayed outstanding stability,operating at 80℃for 168 h while selectively generatingβ-lactones.展开更多
Mechanistic studies of the cleavage and transformation of unactivated C_(sp3)-H bonds are a significant field of chemistry.Overcoming the inherent low acidity of C-H bonds to activate the inert substrates is challenge...Mechanistic studies of the cleavage and transformation of unactivated C_(sp3)-H bonds are a significant field of chemistry.Overcoming the inherent low acidity of C-H bonds to activate the inert substrates is challenge under mild conditions.And their complex multi-step transformations may also hinder mechanistic understanding.Herein,we perform theoretical calculations and experimental studies to explore the C_(sp3)-H bonds activation and acylation mechanisms of toluene/thioether using the relatively weak base LDA.A synergistic"main and auxiliary"model was revealed involving dual lithium metal by LDA dimers,and the aryl dilithium species as an intermediate base can facilitate C_(sp3)-H activation.This model not only aids in understanding the acidity of unactivated C_(sp3)-H bonds and the nucleophilicity of their conjugate bases for their kinetic control through cooperative interactions,but also predicts unusual kinetic isotope effects(KIE)for newly designed 2-(methylthio)naphthalene that are experimentally validated.This research is expected to provide a crucial scenario for the cleavage and transformation of unactivated C_(sp3)-H bonds and the development of new functionalities for alkali metal reagents.展开更多
The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Th...The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.展开更多
Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN ge...Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.展开更多
A support made of mussel-inspired polydopamine-coated magnetic iron oxide nanoparticles （PD-MNPs） was prepared and characterized. The widely used Aspetyillus niger lipase （ANL） was immobilized on the PD-MNPs （ANL...A support made of mussel-inspired polydopamine-coated magnetic iron oxide nanoparticles （PD-MNPs） was prepared and characterized. The widely used Aspetyillus niger lipase （ANL） was immobilized on the PD-MNPs （ANL@PD-MNPs） with a protein loading of 138 mg/g and an activity recovery of 83.6% under optimized conditions. For the immobilization, the pH and immobilization time were investigated. The pH and thermal and storage stability of the ANL@PD-MNPs significant- ly surpassed those of free ANL. The ANL@PD-MNPs had better solvent tolerance than free ANL. The secondary structure of free ANL and ANL@PD-MNPs was analyzed by infrared spectroscopy, A kinetic study demonstrated that the ANL@PD-MNPs had enhanced enzyme-substrate affinity and high catalytic efficiency. The ANL@PD-MNPs was applied as a biocatalyst for the regioselective acylation of dihydromyricetin （DMY） in DMSO and gave a conversion of 79.3%, which was higher than that of previous reports. The ANL@PD-MNPs retained over 55% of its initial activity after 10 cycles of reuse. The ANL@PD-MNPs were readily separated from the reaction system by a magnet. The PD-MNPs is an excellent support for ANL and the resulting ANL@PD-MNPs displayed good potential for the efficient synthesis of dihydromyricetin-3-acetate by enzymatic regioselective acylation.展开更多
By analyzing the key steps that restricted the industrial synthesis of salidroside, selective protection of tyrosol with different acylation reagents was adopted. The strategy facilitated the crystallization of interm...By analyzing the key steps that restricted the industrial synthesis of salidroside, selective protection of tyrosol with different acylation reagents was adopted. The strategy facilitated the crystallization of intermediates, which allowed the scalable synthesis of salidroside. It included a reaction of penta-O-acetyl-β-D-glucose with acyl protected tyrosol in the presence of Lewis acid catalyst（ZnCl2）, followed by deacylation under basic condition（NaOMe/MeOH） to give the salidroside. The total yield of this three-step reaction was 47%. Final product and intermediates were purified by recrystallization, which significantly reduced the cost and made the large scale synthesis feasible.展开更多
As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategie...As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategies exploited. For one compound, a highly reactive intermediate of isothiocyanate was constructed to get the desired piperazinecarbothioamide. The synthesis of the other compound was completed sequentially through Friedel-Crafts acylation, coupling reaction and Michael addition. Both synthetic routes have short steps and acceptable yields, and such strategies can be applied to the synthesis of similar oioerazine-containin~ comoounds.展开更多
4-Acylated or 3,4-diacylated caffeic acid phenethyl ester （CAPE） was prepared as prodrug to improve its stability and lipid solubility. Their neuroprotective activities were assessed by H202 model and 6-OHDA model. ...4-Acylated or 3,4-diacylated caffeic acid phenethyl ester （CAPE） was prepared as prodrug to improve its stability and lipid solubility. Their neuroprotective activities were assessed by H202 model and 6-OHDA model. The results showed that target compounds displayed positive abilities to protect PC 12 nerve cells from oxidative stress injury, superior to that of CAPE. Additionally, target compounds showed high blood-brain barrier permeability.展开更多
AIM To investigate the effects of hydrogen-rich water(HRW) treatment on prevention of ethanol(Et OH)-induced early fatty liver in mice.METHODS In vitro reduction of hydrogen peroxide by HRW was determined with a chemi...AIM To investigate the effects of hydrogen-rich water(HRW) treatment on prevention of ethanol(Et OH)-induced early fatty liver in mice.METHODS In vitro reduction of hydrogen peroxide by HRW was determined with a chemiluminescence system. Female mice were randomly divided into five groups: control,Et OH,Et OH + silymarin,Et OH + HRW and Et OH + silymarin + HRW. Each group was fed a Lieber-De Carli liquid diet containing Et OH or isocaloric maltose dextrin(control diet). Silymarin was used as a positive control to compare HRW efficacy against chronic Et OH-induced hepatotoxicity. HRW was freshly prepared and given at a dosage of 1.2 m L/mouse trice daily. Blood and liver tissue were collected after chronic-binge liquid-diet feeding for 12 wk.RESULTS The in vitro study showed that HRW directly scavenged hydrogen peroxide. The in vivo study showed that HRW increased expression of acyl ghrelin,which was correlated with food intake. HRW treatment significantly reduced Et OH-induced increases in serum alanine aminotransferase,aspartate aminotransferase,triglycerol and total cholesterol levels,hepatic lipid accumulation and inflammatory cytokines,including tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-6. HRW attenuated malondialdehyde level,restored glutathione depletion and increased superoxide dismutase,glutathione peroxidase and catalase activities in the liver. Moreover,HRW reduced TNF-α and IL-6 levels but increased IL-10 and IL-22 levels.CONCLUSION HRW protects against chronic Et OH-induced liver injury,possibly by inducing acyl ghrelin to suppress the pro-inflammatory cytokines TNF-α and IL-6 and induce IL-10 and IL-22,thus activating antioxidant enzymes against oxidative stress.展开更多
基金The projcet was supported by the Nature Science Foundation of Guangdong Province(Grant No 974021)
文摘A variety of aldehydes were converted into acylals in excellent yields with acetic anhydride in the presence of a catalytic amount of tin (IV) chloride supported on silica gel at room temperature.
文摘An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in high yields (86% - 97%) at room temperature under solvent-free conditions. Deprotection of the resulting acylals has also been attained by using the same catalysts under microwave irradiation. This method consistently has advantage of excellent yields (82% - 96%) and a short reaction time (3 - 4 min).
文摘A facile, rapid and solvent-flee method for the conversion of acids and dihalomethane to the corresponding methylene diesters （acylals） using microwave as activators or assistor, is reported. This method is particularly powerful for the diesterification of carboxylic acids, which afford methylene diesters in good to excellent yields （up to 〉99%）. When the intermediate is trapped, a ＂double successive SN2 reactions＂ mechanism is proved.
文摘MWCNTs-C-PO3H2has been used as an efficient,heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.A wide range of aldehydes was studied and corresponding products were obtained in good to excellent yields in short reaction times.Nanocatalyst can be easily recovered by centrifuge and reused for subsequent reactions for at least five times without deterioration in catalytic activity.The major advantages of the present method are high yields,short reaction time,recyclable catalyst and solvent-free reaction conditions at room temperature.
文摘A method for the rapid reduction of acyl chlorides to aldehydes was developed using pinacolborane(HBpin)as the reducing agent.The method exhibits excellent generality for both aromatic and aliphatic substrates,affording aldehydes in isolated yields of up to 88%with broad functional group tolerance,including cyano,halogen,alkenyl,ketone,and ester groups.Moreover,the method enables gram-scale aldehyde synthesis and shows high efficiency in reducing in situ generated acyl chlorides,thereby enhancing its synthetic practicality.
文摘Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehydes via acyl radical intermediates is reported.This method exhibits exceptional functional group tolerance and enables late-stage diversification of peptides and carbonyl-group derivatization.Mechanistic studies confirm a radical-based pathway,while applications in peptide modification highlight its utility in bioorganic chemistry.
基金Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Key Research and Development Program of China under grant 2024YFE0214900+2 种基金the National Natural Science Foundation of China under grant 32272341,he National Key Research and Development Program of China under grant 2023YFD2100401the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition under grant 202401,are gratefully acknowledged.
文摘Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.
文摘Indole[2,1-α]isoquinolines are an important class of bioactive molecules and show good antibacterial activity.In the present study,an efficient copper(I)-catalyzed acylation/cyclization has been developed for the construction of indolo[2,1-α]isoquinoline derivatives by utilizing 2-aryl-N-acryloyl indole and benzohydrazide as reactants in the presence of CuI as catalyst and tert-butyl hydroperoxide as oxidant.The present protocol exhibits good functional group tolerance,and a series of acylated indole[2,1-α]isoquinolines were synthesized in moderate to good yields.Radical trapping experiments indicated that the reaction may involve a radical process.
基金the financial support of the National Natural Science Foundation of China(No.22168009)。
文摘Highly toxic phosgene,diethyl chlorophosphate(DCP)and volatile acyl chlorides endanger our life and public security.To achieve facile sensing and discrimination of multiple target analytes,herein,we presented a single fluorescent probe(BDP-CHD)for high-throughput screening of phosgene,DCP and volatile acyl chlorides.The probe underwent a covalent cascade reaction with phosgene to form boron dipyrromethene(BODIPY)with bright green fluorescence.By contrast,DCP,diphosgene and acyl chlorides can covalently assembled with the probe,giving rise to strong blue fluorescence.The probe has demonstrated high-throughput detection capability,high sensitivity,fast response(within 3 s)and parts per trillion(ppt)level detection limit.Furthermore,a portable platform based on BDP-CHD was constructed,which has achieved high-throughput discrimination of 16 analytes through linear discriminant analysis(LDA).Moreover,a smartphone adaptable RGB recognition pattern was established for the quantitative detection of multi-analytes.Therefore,this portable fluorescence sensing platform can serve as a versatile tool for rapid and high-throughput detection of toxic phosgene,DCP and volatile acyl chlorides.The proposed“one for more”strategy simplifies multi-target discrimination procedures and holds great promise for various sensing applications.
文摘Polyhydroxyalkanoate(PHA),a well-known biodegradable polymer,featuresβ-lactones as its monomers,which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined[Lewis acid]^(+)[Co(CO)_(4)]^(-)catalysts.However,the decomposition of[Co(CO)_(4)]^(-)species at temperatures exceeding 80℃presents a hurdle for the development of commercially viable processes under high-temperature reaction conditions to reduce reaction time.Drawing insights from stable{(acyl)Co(CO)n}intermediates involved in historical HCo(CO)_(4)-catalyzed hydroformylation processes,we sought to the high-temperature catalytic activity of epoxide ring-expansion carbonylation.The developed catalyst system,[(acetyl)Co(CO)_(2)dppp]and[(TPP)CrCl],exhibited exceptional catalytic performance with an unprecedented initial turnover frequency of 4700 h^(-1)at 100℃and a turnover numbers of 93000.Notably,the catalyst displayed outstanding stability,operating at 80℃for 168 h while selectively generatingβ-lactones.
基金the National Key Research and Development Program of China(No.2021YFA1500100)the National Natural Science Foundation of China(Nos.92156017 and 21890722)+1 种基金“Frontiers Science Center for New Organic Matter”,Nankai University(No.63181206)Haihe Laboratory of Sustainable Chemical Transformation of Tianjin(No.24HHWCSS00019)for generous financial support。
文摘Mechanistic studies of the cleavage and transformation of unactivated C_(sp3)-H bonds are a significant field of chemistry.Overcoming the inherent low acidity of C-H bonds to activate the inert substrates is challenge under mild conditions.And their complex multi-step transformations may also hinder mechanistic understanding.Herein,we perform theoretical calculations and experimental studies to explore the C_(sp3)-H bonds activation and acylation mechanisms of toluene/thioether using the relatively weak base LDA.A synergistic"main and auxiliary"model was revealed involving dual lithium metal by LDA dimers,and the aryl dilithium species as an intermediate base can facilitate C_(sp3)-H activation.This model not only aids in understanding the acidity of unactivated C_(sp3)-H bonds and the nucleophilicity of their conjugate bases for their kinetic control through cooperative interactions,but also predicts unusual kinetic isotope effects(KIE)for newly designed 2-(methylthio)naphthalene that are experimentally validated.This research is expected to provide a crucial scenario for the cleavage and transformation of unactivated C_(sp3)-H bonds and the development of new functionalities for alkali metal reagents.
文摘The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.
文摘Several phenylselenyl esters were selected as precursors of acyl radicals and synthesised by our established method. Treatment of these phenylselenyl esters with tributyltinhydride and AIBN generated the corresponding acyl radicals, which were found to proceed in 5 exo trig or 6 endo trig cyclisations to afford high yields of cyclopentanones and cyclohexanones, The substitution groups on the substrates have played an important role on the regioselectivity of cyclisations.
基金supported by the National Natural Science Foundation of China(21336002,21222606,21376096)the Key Program of Guangdong Natural Science Foundation(S2013020013049)+1 种基金the Fundamental Research Funds for the Chinese Universities(2015PT002,2015ZP009)the Program of State Key Laboratory of Pulp and Paper Engineering(2015C04)~~
文摘A support made of mussel-inspired polydopamine-coated magnetic iron oxide nanoparticles （PD-MNPs） was prepared and characterized. The widely used Aspetyillus niger lipase （ANL） was immobilized on the PD-MNPs （ANL@PD-MNPs） with a protein loading of 138 mg/g and an activity recovery of 83.6% under optimized conditions. For the immobilization, the pH and immobilization time were investigated. The pH and thermal and storage stability of the ANL@PD-MNPs significant- ly surpassed those of free ANL. The ANL@PD-MNPs had better solvent tolerance than free ANL. The secondary structure of free ANL and ANL@PD-MNPs was analyzed by infrared spectroscopy, A kinetic study demonstrated that the ANL@PD-MNPs had enhanced enzyme-substrate affinity and high catalytic efficiency. The ANL@PD-MNPs was applied as a biocatalyst for the regioselective acylation of dihydromyricetin （DMY） in DMSO and gave a conversion of 79.3%, which was higher than that of previous reports. The ANL@PD-MNPs retained over 55% of its initial activity after 10 cycles of reuse. The ANL@PD-MNPs were readily separated from the reaction system by a magnet. The PD-MNPs is an excellent support for ANL and the resulting ANL@PD-MNPs displayed good potential for the efficient synthesis of dihydromyricetin-3-acetate by enzymatic regioselective acylation.
基金the National Basic Research Program of China(973 Program,Grant No.2012CB822100)the National Key Technology R&D Program"New Drug Innovation"of China(Grant No.2012ZX09502001-001)the National Natural Science Foundation of China(Grant No.21232002,21072016 and 21072017)
文摘By analyzing the key steps that restricted the industrial synthesis of salidroside, selective protection of tyrosol with different acylation reagents was adopted. The strategy facilitated the crystallization of intermediates, which allowed the scalable synthesis of salidroside. It included a reaction of penta-O-acetyl-β-D-glucose with acyl protected tyrosol in the presence of Lewis acid catalyst（ZnCl2）, followed by deacylation under basic condition（NaOMe/MeOH） to give the salidroside. The total yield of this three-step reaction was 47%. Final product and intermediates were purified by recrystallization, which significantly reduced the cost and made the large scale synthesis feasible.
基金National Basic Research Program of China(Grant No.2012CB518000)the National Natural Science Foundation of China(Grant No.21172012)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120001110010)
文摘As important constitutes in many drugs, piperazine comprised compounds are of great interest for drug design. In this paper, two piperazine-based compounds were synthesized for the first time, with different strategies exploited. For one compound, a highly reactive intermediate of isothiocyanate was constructed to get the desired piperazinecarbothioamide. The synthesis of the other compound was completed sequentially through Friedel-Crafts acylation, coupling reaction and Michael addition. Both synthetic routes have short steps and acceptable yields, and such strategies can be applied to the synthesis of similar oioerazine-containin~ comoounds.
基金National Natural Science Foundation of China(Grant No.201310061931.8)
文摘4-Acylated or 3,4-diacylated caffeic acid phenethyl ester （CAPE） was prepared as prodrug to improve its stability and lipid solubility. Their neuroprotective activities were assessed by H202 model and 6-OHDA model. The results showed that target compounds displayed positive abilities to protect PC 12 nerve cells from oxidative stress injury, superior to that of CAPE. Additionally, target compounds showed high blood-brain barrier permeability.
基金Supported by a grant from the Chung Shan Medical University,No.CSMU0150011
文摘AIM To investigate the effects of hydrogen-rich water(HRW) treatment on prevention of ethanol(Et OH)-induced early fatty liver in mice.METHODS In vitro reduction of hydrogen peroxide by HRW was determined with a chemiluminescence system. Female mice were randomly divided into five groups: control,Et OH,Et OH + silymarin,Et OH + HRW and Et OH + silymarin + HRW. Each group was fed a Lieber-De Carli liquid diet containing Et OH or isocaloric maltose dextrin(control diet). Silymarin was used as a positive control to compare HRW efficacy against chronic Et OH-induced hepatotoxicity. HRW was freshly prepared and given at a dosage of 1.2 m L/mouse trice daily. Blood and liver tissue were collected after chronic-binge liquid-diet feeding for 12 wk.RESULTS The in vitro study showed that HRW directly scavenged hydrogen peroxide. The in vivo study showed that HRW increased expression of acyl ghrelin,which was correlated with food intake. HRW treatment significantly reduced Et OH-induced increases in serum alanine aminotransferase,aspartate aminotransferase,triglycerol and total cholesterol levels,hepatic lipid accumulation and inflammatory cytokines,including tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-6. HRW attenuated malondialdehyde level,restored glutathione depletion and increased superoxide dismutase,glutathione peroxidase and catalase activities in the liver. Moreover,HRW reduced TNF-α and IL-6 levels but increased IL-10 and IL-22 levels.CONCLUSION HRW protects against chronic Et OH-induced liver injury,possibly by inducing acyl ghrelin to suppress the pro-inflammatory cytokines TNF-α and IL-6 and induce IL-10 and IL-22,thus activating antioxidant enzymes against oxidative stress.
