Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.^(2,6)] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of meso-diacetate 5.
Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one （ATMC） with 5, 5-dimethyl- 1, 3-dioxan-2-one （DTC） were successfully synthesized for the first time using immobilized porcine pancreas lipase （IPPL） as cata...Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one （ATMC） with 5, 5-dimethyl- 1, 3-dioxan-2-one （DTC） were successfully synthesized for the first time using immobilized porcine pancreas lipase （IPPL） as catalyst. The resulting copolymers were characterized by IR, ^1H NMR, ^13C NMR and GPC. The molecular weight （Mn） of the copolymer with molar feed ratio of 10：90 （ATMC：DTC） was 9300 and the polydispersity was 1.31, while the Mn increased to 14300 and polydispersity of 1.25 with the feed ratio of 50：50. Moreover, the composition of the copolymers agreed well with the monomer feed.展开更多
The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculat...The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculating kinetic parameters, KM,Ki and Urn were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation of o-dihydroxybenzene by m-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type, KM=6.224×10-3 mol L-1, Ki=2. 363 × 10-2 mol. L-1.展开更多
Solar dermatitis is an acute or chronic high incidence of skin injury caused by ultraviolet(UV)radiation based on strong sunlight,which seriously endangers people's health.In this study,we designed and demonstrate...Solar dermatitis is an acute or chronic high incidence of skin injury caused by ultraviolet(UV)radiation based on strong sunlight,which seriously endangers people's health.In this study,we designed and demonstrated enzyme-catalyzed semi-inter penetrating polymer network(Semi-IPN)sprayable nanodrug-loaded hydrogels based on gelatin,3-(4-hydroxyphenyl)propionic acid(HPA),polyvinyl alcohol(PVA),glycerol,and dexamethasone sodium phosphate(DEXP)for solar dermatitis.The hydrogels had high water content,excellent biocompatibility,effective encapsulation and sustained release of nanodrugs,antiinflammatory,and strong anti-ultraviolet B(anti-UVB)radiation properties based on glycerol and phenol functional groups,but also controllable spray gelation mode to make them adhere well on the dynamic skin surfaces and achieve continuous transdermal drugs delivery for solar dermatitis.The sprayable nanodrug-loaded hydrogel systems could be used as a highly effective therapeutic method for solar dermatitis,and also provide a good strategy for designing novel nanodrug-loaded hydrogel delivery systems.展开更多
文摘Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.^(2,6)] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of meso-diacetate 5.
基金The authors are grateful for the financial support of the National Natural Science Foundation of China （No. 20104005）.
文摘Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one （ATMC） with 5, 5-dimethyl- 1, 3-dioxan-2-one （DTC） were successfully synthesized for the first time using immobilized porcine pancreas lipase （IPPL） as catalyst. The resulting copolymers were characterized by IR, ^1H NMR, ^13C NMR and GPC. The molecular weight （Mn） of the copolymer with molar feed ratio of 10：90 （ATMC：DTC） was 9300 and the polydispersity was 1.31, while the Mn increased to 14300 and polydispersity of 1.25 with the feed ratio of 50：50. Moreover, the composition of the copolymers agreed well with the monomer feed.
文摘The thermokinetic reduced extent equations of reversible inhibitions for Michaiels-Menten enzymatic reaction were deduced, and then the criteria for distingushing inhibition type was given and the methods for calculating kinetic parameters, KM,Ki and Urn were suggested. This theory was applied to inverstigate the inhibited thermokinetics of laccase-catalyzed oxidation of o-dihydroxybenzene by m-dihydroxybenzene. The experimental results show the inhibition belongs to reversible competitive type, KM=6.224×10-3 mol L-1, Ki=2. 363 × 10-2 mol. L-1.
基金supported by the National Natural Science Foundation of China(Nos.22078265,22108225,and 21838009)the Shaanxi Provincial Science Foundation(Nos.2017SF-201 and 2021JQ-434)China Postdoctoral Science Foundation(No.2018M643720).
文摘Solar dermatitis is an acute or chronic high incidence of skin injury caused by ultraviolet(UV)radiation based on strong sunlight,which seriously endangers people's health.In this study,we designed and demonstrated enzyme-catalyzed semi-inter penetrating polymer network(Semi-IPN)sprayable nanodrug-loaded hydrogels based on gelatin,3-(4-hydroxyphenyl)propionic acid(HPA),polyvinyl alcohol(PVA),glycerol,and dexamethasone sodium phosphate(DEXP)for solar dermatitis.The hydrogels had high water content,excellent biocompatibility,effective encapsulation and sustained release of nanodrugs,antiinflammatory,and strong anti-ultraviolet B(anti-UVB)radiation properties based on glycerol and phenol functional groups,but also controllable spray gelation mode to make them adhere well on the dynamic skin surfaces and achieve continuous transdermal drugs delivery for solar dermatitis.The sprayable nanodrug-loaded hydrogel systems could be used as a highly effective therapeutic method for solar dermatitis,and also provide a good strategy for designing novel nanodrug-loaded hydrogel delivery systems.
