1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In th...1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...展开更多
The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring syntho...The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.展开更多
A series of highly timctionalized 1,4-dihydropyridines was synthesized via one-pot multicomponent reactions of aromatic aldehyde,malononitrile and N-methyl-1-(methylthio)-2-nitroethenamine using Porcine pancreatic lip...A series of highly timctionalized 1,4-dihydropyridines was synthesized via one-pot multicomponent reactions of aromatic aldehyde,malononitrile and N-methyl-1-(methylthio)-2-nitroethenamine using Porcine pancreatic lipase(PPL)as catalyst in DMSO.This protocol is featured by mild reaction conditions,simple operation and environmental acceptability.展开更多
The effect of low energy ultrasound in biochemistry and biotechnology has attracted great attention in recent years.It can enhance substrate dissolution and improve mass transfer within and outside of a cell,both of w...The effect of low energy ultrasound in biochemistry and biotechnology has attracted great attention in recent years.It can enhance substrate dissolution and improve mass transfer within and outside of a cell,both of which are beneficial to the synthesis of fructose ester.Here we describe the experimental study of the effect of ultrasounds of different intensity on the lipase-catalyzed synthesis of fructose ester in the solvent butanone.The results were compared with control reactions performed with no ultrasound.High performance liquid chromatography(HPLC)and thin layer chromatography(TLC)were used for qualitative and quantitative analyses.The results show the following:1)the concentration of monoester and diester increased with the reaction time,either with or without ultrasonic irradiation.Low energy ultrasound accelerated the reaction due to the effect of ultrasonic steady cavitations,and high energy ultrasound was not beneficial to the reaction.2)The application of ultrasound played an important role in our lipase-catalyzed reaction.It decreased reaction time as compared to a reaction without ultrasound that resulted in the same yield,increased reaction rate,and enhanced the amount of fructose ester produced.When the frequency was 10 kHz and sound intensity was 0.16W·m^(-2),the concentration of ester was twofold more than without ultrasonic irradiation after a reaction time of up to 12 h.With the proper ultrasonic parameters,the overall concentration of production appeared to increase exponentially with the reaction time.3)Ultrasound had little effect on the initial reaction rate,and continuous ultrasonic irradiation was favorable for the reaction.The longer the reaction continued,the more obvious the effects of the ultrasound became in our experiments.展开更多
PVA/Chitosan(CS) composite membrane was used for enzyme processing of fats and oils. The concentration of lipase and cross-linking agent which influence the immobilization of lipase in membrane were determined. Epichl...PVA/Chitosan(CS) composite membrane was used for enzyme processing of fats and oils. The concentration of lipase and cross-linking agent which influence the immobilization of lipase in membrane were determined. Epichlorohydrin is used as the cross-linking agent. The immobilized lipase is 0.66 u·cm -2 and the recovery of immobilized lipase is 24%. The membrane reactor was tested to synthesis monoglyceride(MG), which could be used many times without loss conversion yield of MG. The PVA/CS lipase membrane reactor is a new reactor for lipase catalytic biphase systems.展开更多
文摘1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...
文摘The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.
基金the National Natural Science Foundation of China(No.21706236)the China Postdoctoral Science Foundation(No.2016M592012)the Foundation for Selected Postdoctoral Project of Zhejiang Province,China(No.BSH1502150).
文摘A series of highly timctionalized 1,4-dihydropyridines was synthesized via one-pot multicomponent reactions of aromatic aldehyde,malononitrile and N-methyl-1-(methylthio)-2-nitroethenamine using Porcine pancreatic lipase(PPL)as catalyst in DMSO.This protocol is featured by mild reaction conditions,simple operation and environmental acceptability.
基金the financial support of the Innovation Fund for Doctoral Theses and the Nanjing University of Technology(No.BSCX200811)the Fundation of the Nanjing University of Technology(No.39708006).
文摘The effect of low energy ultrasound in biochemistry and biotechnology has attracted great attention in recent years.It can enhance substrate dissolution and improve mass transfer within and outside of a cell,both of which are beneficial to the synthesis of fructose ester.Here we describe the experimental study of the effect of ultrasounds of different intensity on the lipase-catalyzed synthesis of fructose ester in the solvent butanone.The results were compared with control reactions performed with no ultrasound.High performance liquid chromatography(HPLC)and thin layer chromatography(TLC)were used for qualitative and quantitative analyses.The results show the following:1)the concentration of monoester and diester increased with the reaction time,either with or without ultrasonic irradiation.Low energy ultrasound accelerated the reaction due to the effect of ultrasonic steady cavitations,and high energy ultrasound was not beneficial to the reaction.2)The application of ultrasound played an important role in our lipase-catalyzed reaction.It decreased reaction time as compared to a reaction without ultrasound that resulted in the same yield,increased reaction rate,and enhanced the amount of fructose ester produced.When the frequency was 10 kHz and sound intensity was 0.16W·m^(-2),the concentration of ester was twofold more than without ultrasonic irradiation after a reaction time of up to 12 h.With the proper ultrasonic parameters,the overall concentration of production appeared to increase exponentially with the reaction time.3)Ultrasound had little effect on the initial reaction rate,and continuous ultrasonic irradiation was favorable for the reaction.The longer the reaction continued,the more obvious the effects of the ultrasound became in our experiments.
基金国家自然科学基金! (No .2 96760 0 1 )山东大学国家微生物技术重点实验室开放基金河北省自然科学基金资助
文摘PVA/Chitosan(CS) composite membrane was used for enzyme processing of fats and oils. The concentration of lipase and cross-linking agent which influence the immobilization of lipase in membrane were determined. Epichlorohydrin is used as the cross-linking agent. The immobilized lipase is 0.66 u·cm -2 and the recovery of immobilized lipase is 24%. The membrane reactor was tested to synthesis monoglyceride(MG), which could be used many times without loss conversion yield of MG. The PVA/CS lipase membrane reactor is a new reactor for lipase catalytic biphase systems.
