We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as ...We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.展开更多
As the only naturally occurring stable derivative of L-ascorbic acid(AA;vitamin C),2-O-β-D-glucopyranosyl-L-ascorbic acid(AA-2βG)is hydrolyzed in vivo to release active AA.AA-2βG exhibits strong antioxidant and ant...As the only naturally occurring stable derivative of L-ascorbic acid(AA;vitamin C),2-O-β-D-glucopyranosyl-L-ascorbic acid(AA-2βG)is hydrolyzed in vivo to release active AA.AA-2βG exhibits strong antioxidant and antiphotoaging effects comparable to those of AA,and it plays a key role in maintaining organismal health.Owing to its superior stability and bioavailability,AA-2βG is considered as a promising,longer-lasting natural alternative to conventional vitamin C.It was first identified and is particularly abundant in Lycii Fructus(Gouqizi in Chinese)but has been detected in several crop plants.This review offers a comprehensive overview of recent advances in AA-2βG research,covering key aspects including discovery,structure,natural sources,extraction and detection methods,chemical and in vitro enzymatic synthesis,biosynthetic pathways,as well as applications in health care,skin care,and functional foods.Additionally,we highlight strategies for leveraging plant resources and enhancing AA-2βG biosynthesis,which are expected to accelerate future research and support the sustainable development and utilization of AA-2βG and other high-value natural products.展开更多
基金the Science and Technology R&D Major Project of Jiangxi Province(No.20244AFI92001)the National Natural Science Foundation of China(Nos.22071033 and 21801047)for the financial supports.
文摘We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.
基金funded by the National Key Research and Development Program(Nos.2023YFC3504104 and 2024YFD2100700)the Fundamental Research Funds for the Central public welfare research institutes(No.ZZ13-YQ-101)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(No.CI2023E002-Y-28).
文摘As the only naturally occurring stable derivative of L-ascorbic acid(AA;vitamin C),2-O-β-D-glucopyranosyl-L-ascorbic acid(AA-2βG)is hydrolyzed in vivo to release active AA.AA-2βG exhibits strong antioxidant and antiphotoaging effects comparable to those of AA,and it plays a key role in maintaining organismal health.Owing to its superior stability and bioavailability,AA-2βG is considered as a promising,longer-lasting natural alternative to conventional vitamin C.It was first identified and is particularly abundant in Lycii Fructus(Gouqizi in Chinese)but has been detected in several crop plants.This review offers a comprehensive overview of recent advances in AA-2βG research,covering key aspects including discovery,structure,natural sources,extraction and detection methods,chemical and in vitro enzymatic synthesis,biosynthetic pathways,as well as applications in health care,skin care,and functional foods.Additionally,we highlight strategies for leveraging plant resources and enhancing AA-2βG biosynthesis,which are expected to accelerate future research and support the sustainable development and utilization of AA-2βG and other high-value natural products.
