The preparation of immobilized enzyme with excellent performance is one of the difficulties that restrict the application of enzyme catalysis technology.Here,Candida rugosa lipase(CRL)was firstly adsorbed on the surfa...The preparation of immobilized enzyme with excellent performance is one of the difficulties that restrict the application of enzyme catalysis technology.Here,Candida rugosa lipase(CRL)was firstly adsorbed on the surface of magnetic zeolitic imidazolate framework-8(ZIF-8)nanospheres,which was further encapsulated with a mesoporous SiO_(2)nano-membrane formed by tetraethyl orthosilicate(TEOS)polycondensation.Consequently,lipase could be firmly immobilized on carrier surface by physical binding rather than chemical binding,which did not damage the active conformation of enzyme.There were mesopores on the silica nano-membrane,which could improve the accessibility of enzyme and its apparent catalytic activity.Moreover,silica membrane encapsulation could also improve the stability of enzyme,suggesting an effective enzyme immobilization strategy.It showed that TEOS amount and the encapsulation time had significant effects on the thickness of silica membrane and the enzyme activity.The analysis in enzyme activity and protein secondary structure showed that lipase encapsulated in silica membrane retained the active conformation to the greatest extent.Compared with the adsorbed lipase,the encapsulated lipase increased its thermostability by 3 times and resistance to chemical denaturants by 7 times.The relative enzyme activity remained around 80%after 8 repetitions,while the adsorbed lipase only remained at7.3%.展开更多
Objective:To explore pancreatic lipase inhibitory activity under different extraction conditions in order to track the most potent extract.Methods:The methanolic extract and its fractions in solvents of increasing pol...Objective:To explore pancreatic lipase inhibitory activity under different extraction conditions in order to track the most potent extract.Methods:The methanolic extract and its fractions in solvents of increasing polarity,ether,chloroform,ethyl acetate,n-butanol and water,were made through cold maceration.Extracts in ethanol,ethyl acetate,acetone and chloroform were similarly prepared.Aqueous extract was prepared through hot decoction method.A reported method was used to determine lipase inhibitory activity of extracts and fractions over wide ranges of concentrations.Results:The extracts and fractions exhibited concentration dependent activity.The IC50(μg/mL)values of methanolic,ethanolic,chloroform,ethyl acetate,acetone,ethyl acetate(after washing with water)and aqueous decoction were 293.40,266.47,157.59,182.12,352.34,257.00,and 190.00,respectively.The activity of chloroform,ethyl acetate and aqueous extracts were close to that of the drug orlistat(IC50 146μg/mL).Out of the fractions of the methanolic extract,the chloroform fraction was most active(IC50 189.6μg/mL).The order of inhibitory activity of the fractions was as follows:chloroform>ether>n-butanolic>aqueous>ethyl acetate.The GC/MS analysis of the most active chloroform faction showed the presence of hexadecanoic acid,methyl hexadecanoate,isopropyl palmitate,methyl 9,12-octadecadienate,and methyl 9,12,15-octadecatrienoate.Conclusions:The study suggests that Lagenaria siceraria has potential to inhibit pancreatic lipase activity,suppressing lipid digestion and thereby diminishing entry of lipids into the body.Regular intake of aqueous decoction of the fruit may therefore be recommended for control of obesity.Fatty acids and their esters may play role as inhibitors of lipase.展开更多
Determination of brazilin by High Performance Liquid Chromatography （HPLC） method and measurement of the antioxidative and lipase inhibition effects in the Caesalpinia sappan wood from various locations in Indonesia...Determination of brazilin by High Performance Liquid Chromatography （HPLC） method and measurement of the antioxidative and lipase inhibition effects in the Caesalpinia sappan wood from various locations in Indonesia is described in this paper. Brazilin was separated from sample matrix using a reversed phase C 18, Shim-pack VP column with the mobile phase in a gradient elution for45 min from 5% to 100% methanol in 0.05% aqueous trifluoroacetic acid. Brazilin in ethanolic extracts ofC. sappan wood was in the range of 5.81 to 24.85 mg/g on dry-weight basis. Antioxidant and lipase inhibition activities expressed by IC50 values from all samples were in the range from 6.60 to 11.53 μg/mL and 50.76 to 203.21 μg/mL, respectively. Antioxidative and lipase inhibition potency of all ethanolic extracts were compared to vitamin C and chloramphenicol, isopropyl methylphenol and tetracyclin, respectively.展开更多
A simple and efficient Knoevenagel condensation between a b-unsaturated aldehydes and active methylene compounds is reported.Notably,this condensation can be catalyzed by PPL（lipase from porcine pancreas） with satis...A simple and efficient Knoevenagel condensation between a b-unsaturated aldehydes and active methylene compounds is reported.Notably,this condensation can be catalyzed by PPL（lipase from porcine pancreas） with satisfied yields（49%–92%）.Moreover,PPL induces moderate Z/E selectivity in the Knoevenagel condensation.展开更多
A metagenomic library recombinant clone CAPL3, an Escherichia coli strain generated by transformed with metagenomic library from deep-sea sediments, can efficiently produce cold active lipase. The effects of both temp...A metagenomic library recombinant clone CAPL3, an Escherichia coli strain generated by transformed with metagenomic library from deep-sea sediments, can efficiently produce cold active lipase. The effects of both temperature and dissolved oxygen（DO） on cold active lipase production by batch culture of metagenomic library recombinant clone（CAPL3） from deep-sea sediment were investigated. First, a two-stage temperature control strategy was developed, in which the temperature was kept at 34 ℃ for the first 15 h, and then switched to30 ℃. The cold active lipase activity and productivity reached 315.2 U·ml^-1and 8.08 U·ml^-1·h^-1, respectively,increased by both 14.5% compared to the results obtained with temperature controlled at 30℃. In addition, different DO control modes were conducted, based on the data obtained from the different DO control strategies and analysis of kinetics parameters at different DO levels. A step-wise temperature and DO control strategy were developed to improve lipase production, i.e., temperature and DO level were controlled at 34℃, 30% during 0–15 h;30 ℃, 30% during 15–18 h, and 30 ℃, 20% during 18–39 h. With this strategy, the maximum lipase activity reached 354.6 U·ml^-1at 39 h, which was 28.8% higher than that achieved without temperature and DO control（275.3 U·ml^-1）.展开更多
This research reported the effect of peeling naked oats with a peeling machine equipped with the flexible alloy blade.Results showed that the flexible alloy blade could achieve the same effect as traditional abrasive ...This research reported the effect of peeling naked oats with a peeling machine equipped with the flexible alloy blade.Results showed that the flexible alloy blade could achieve the same effect as traditional abrasive rolls. Furthermore, the new peeling method had hardly damage to the oat kernels. The result of scanning electron microscopy indicated the surface of peeled naked oats by the flexible alloy blade is homogeneous. The gap between the flexible alloy blade and the slotted screen could change the particle sizes of the flours obtained, which differed from traditional peeling machines. In addition, peeling for 15 seconds significantly reduced the microbial contaminants. The removal of outer layer decreased the lipase activity. The technological parameters were optimized by orthogonal L_9(3~4) test, the results showed a 30 s peeling time and 2% second-addition of water contributed to the peeling rate. The texture analysis demonstrate that the hardness of cooked groats decreases obviously after peeling treatments.展开更多
In vitro digestion studies demonstrate large potential to gain more and quicker insights into the underlying mechanisms of feed additives,allowing the optimization of feed design.Unfortunately,current in vitro digesti...In vitro digestion studies demonstrate large potential to gain more and quicker insights into the underlying mechanisms of feed additives,allowing the optimization of feed design.Unfortunately,current in vitro digestion models relevant for broiler chickens lack sufficient description in terms of protocols and standardisation used.Furthermore,no distinction is made between the different life phases of these animals(starter,grower,and finisher).Hence,our research aimed to establish adapted in vitro digestion conditions,corresponding to the 3 life phases in broilers,with specific focus on lipid digestion.The effect of 3 different bile salt concentrations of 2,10,and 20 mM,and 3 different lipase activities of 5,20,and 100 U/mL,on in vitro lipid digestion kinetics were evaluated using a full factorial design.These values were selected to represent starter,grower,and finisher birds,respectively.Our findings showed that the extent of lipid digestion was mainly influenced by lipase activity.The rate of lipid digestion was affected by an interplay between bile salt concentration and lipase activity,due to possible lipase inhibition at certain bile salt concentrations.Overall,this work resulted in 3 in vitro lipid digestion models representative for starter,grower,and finisher birds.In conclusion,this research showed the impact of adapted in vitro digestion conditions on lipid digestion kinetics and thus the need for these conditions relevant for each life phase of broilers.展开更多
基金the financial supports from the National Natural Science Foundation of China(Nos.22378093,21878065)Natural Science Foundation of Hebei Province,China(No.E2022201100)+2 种基金the Science and Technology Support Plan of Baoding City(No.2241ZF111)the Medical Science Foundation of Hebei University(No.2021A09)the Foundation of Affiliated Hospital of Hebei University(No.2021Z003)。
文摘The preparation of immobilized enzyme with excellent performance is one of the difficulties that restrict the application of enzyme catalysis technology.Here,Candida rugosa lipase(CRL)was firstly adsorbed on the surface of magnetic zeolitic imidazolate framework-8(ZIF-8)nanospheres,which was further encapsulated with a mesoporous SiO_(2)nano-membrane formed by tetraethyl orthosilicate(TEOS)polycondensation.Consequently,lipase could be firmly immobilized on carrier surface by physical binding rather than chemical binding,which did not damage the active conformation of enzyme.There were mesopores on the silica nano-membrane,which could improve the accessibility of enzyme and its apparent catalytic activity.Moreover,silica membrane encapsulation could also improve the stability of enzyme,suggesting an effective enzyme immobilization strategy.It showed that TEOS amount and the encapsulation time had significant effects on the thickness of silica membrane and the enzyme activity.The analysis in enzyme activity and protein secondary structure showed that lipase encapsulated in silica membrane retained the active conformation to the greatest extent.Compared with the adsorbed lipase,the encapsulated lipase increased its thermostability by 3 times and resistance to chemical denaturants by 7 times.The relative enzyme activity remained around 80%after 8 repetitions,while the adsorbed lipase only remained at7.3%.
基金Pakistan Science Foundation(PSF),Islamabad,for its financial support for the study(PSF/NSLP/P-FCCU)
文摘Objective:To explore pancreatic lipase inhibitory activity under different extraction conditions in order to track the most potent extract.Methods:The methanolic extract and its fractions in solvents of increasing polarity,ether,chloroform,ethyl acetate,n-butanol and water,were made through cold maceration.Extracts in ethanol,ethyl acetate,acetone and chloroform were similarly prepared.Aqueous extract was prepared through hot decoction method.A reported method was used to determine lipase inhibitory activity of extracts and fractions over wide ranges of concentrations.Results:The extracts and fractions exhibited concentration dependent activity.The IC50(μg/mL)values of methanolic,ethanolic,chloroform,ethyl acetate,acetone,ethyl acetate(after washing with water)and aqueous decoction were 293.40,266.47,157.59,182.12,352.34,257.00,and 190.00,respectively.The activity of chloroform,ethyl acetate and aqueous extracts were close to that of the drug orlistat(IC50 146μg/mL).Out of the fractions of the methanolic extract,the chloroform fraction was most active(IC50 189.6μg/mL).The order of inhibitory activity of the fractions was as follows:chloroform>ether>n-butanolic>aqueous>ethyl acetate.The GC/MS analysis of the most active chloroform faction showed the presence of hexadecanoic acid,methyl hexadecanoate,isopropyl palmitate,methyl 9,12-octadecadienate,and methyl 9,12,15-octadecatrienoate.Conclusions:The study suggests that Lagenaria siceraria has potential to inhibit pancreatic lipase activity,suppressing lipid digestion and thereby diminishing entry of lipids into the body.Regular intake of aqueous decoction of the fruit may therefore be recommended for control of obesity.Fatty acids and their esters may play role as inhibitors of lipase.
文摘Determination of brazilin by High Performance Liquid Chromatography （HPLC） method and measurement of the antioxidative and lipase inhibition effects in the Caesalpinia sappan wood from various locations in Indonesia is described in this paper. Brazilin was separated from sample matrix using a reversed phase C 18, Shim-pack VP column with the mobile phase in a gradient elution for45 min from 5% to 100% methanol in 0.05% aqueous trifluoroacetic acid. Brazilin in ethanolic extracts ofC. sappan wood was in the range of 5.81 to 24.85 mg/g on dry-weight basis. Antioxidant and lipase inhibition activities expressed by IC50 values from all samples were in the range from 6.60 to 11.53 μg/mL and 50.76 to 203.21 μg/mL, respectively. Antioxidative and lipase inhibition potency of all ethanolic extracts were compared to vitamin C and chloramphenicol, isopropyl methylphenol and tetracyclin, respectively.
基金the financial support from the National Natural Science Foundation of China (Nos. 21172093, 31070708, and 21072075)the Natural Science Foundation of Jilin Province of China (Nos. 201115039 and 20140101141JC)the Scientific Research Fund of Jilin University (No. 450060326007)
文摘A simple and efficient Knoevenagel condensation between a b-unsaturated aldehydes and active methylene compounds is reported.Notably,this condensation can be catalyzed by PPL（lipase from porcine pancreas） with satisfied yields（49%–92%）.Moreover,PPL induces moderate Z/E selectivity in the Knoevenagel condensation.
基金Supported by the Hi-Tech Research and Development Program of China(863 program of China2012AA092103)China Ocean Mineral Resources R&D Association(DY125-15-T-06)
文摘A metagenomic library recombinant clone CAPL3, an Escherichia coli strain generated by transformed with metagenomic library from deep-sea sediments, can efficiently produce cold active lipase. The effects of both temperature and dissolved oxygen（DO） on cold active lipase production by batch culture of metagenomic library recombinant clone（CAPL3） from deep-sea sediment were investigated. First, a two-stage temperature control strategy was developed, in which the temperature was kept at 34 ℃ for the first 15 h, and then switched to30 ℃. The cold active lipase activity and productivity reached 315.2 U·ml^-1and 8.08 U·ml^-1·h^-1, respectively,increased by both 14.5% compared to the results obtained with temperature controlled at 30℃. In addition, different DO control modes were conducted, based on the data obtained from the different DO control strategies and analysis of kinetics parameters at different DO levels. A step-wise temperature and DO control strategy were developed to improve lipase production, i.e., temperature and DO level were controlled at 34℃, 30% during 0–15 h;30 ℃, 30% during 15–18 h, and 30 ℃, 20% during 18–39 h. With this strategy, the maximum lipase activity reached 354.6 U·ml^-1at 39 h, which was 28.8% higher than that achieved without temperature and DO control（275.3 U·ml^-1）.
基金Supported by National Natural Science Foundation of China(No.31571873)National College Students Innovation and Entrepreneurship Training Program Project(201710463002)
文摘This research reported the effect of peeling naked oats with a peeling machine equipped with the flexible alloy blade.Results showed that the flexible alloy blade could achieve the same effect as traditional abrasive rolls. Furthermore, the new peeling method had hardly damage to the oat kernels. The result of scanning electron microscopy indicated the surface of peeled naked oats by the flexible alloy blade is homogeneous. The gap between the flexible alloy blade and the slotted screen could change the particle sizes of the flours obtained, which differed from traditional peeling machines. In addition, peeling for 15 seconds significantly reduced the microbial contaminants. The removal of outer layer decreased the lipase activity. The technological parameters were optimized by orthogonal L_9(3~4) test, the results showed a 30 s peeling time and 2% second-addition of water contributed to the peeling rate. The texture analysis demonstrate that the hardness of cooked groats decreases obviously after peeling treatments.
基金D.Michels is a Doctoral Researcher funded by VLAIO(Flanders Innovation and Entrepreneurship,Belgium)in the context of a Baekeland mandate(HBC.2020.2836)S.H.E.Verkempinck is a Postdoctoral Researcher funded by the Research Foundation Flanders(FWO–Grant no.1222420N).
文摘In vitro digestion studies demonstrate large potential to gain more and quicker insights into the underlying mechanisms of feed additives,allowing the optimization of feed design.Unfortunately,current in vitro digestion models relevant for broiler chickens lack sufficient description in terms of protocols and standardisation used.Furthermore,no distinction is made between the different life phases of these animals(starter,grower,and finisher).Hence,our research aimed to establish adapted in vitro digestion conditions,corresponding to the 3 life phases in broilers,with specific focus on lipid digestion.The effect of 3 different bile salt concentrations of 2,10,and 20 mM,and 3 different lipase activities of 5,20,and 100 U/mL,on in vitro lipid digestion kinetics were evaluated using a full factorial design.These values were selected to represent starter,grower,and finisher birds,respectively.Our findings showed that the extent of lipid digestion was mainly influenced by lipase activity.The rate of lipid digestion was affected by an interplay between bile salt concentration and lipase activity,due to possible lipase inhibition at certain bile salt concentrations.Overall,this work resulted in 3 in vitro lipid digestion models representative for starter,grower,and finisher birds.In conclusion,this research showed the impact of adapted in vitro digestion conditions on lipid digestion kinetics and thus the need for these conditions relevant for each life phase of broilers.
