(R)-1,3-butanediol is an important pharmaceutical intermediate, and the synthesis of(R)-1,3-butanediol using green biological methods has recently been of interest for industrial application. Here, a novel strain QC-1...(R)-1,3-butanediol is an important pharmaceutical intermediate, and the synthesis of(R)-1,3-butanediol using green biological methods has recently been of interest for industrial application. Here, a novel strain QC-1 that efficiently transforms 4-hydroxy-2-butanone to(R)-1,3-butanediol was isolated from soil samples. Based on morphological, physiological, and biochemical tests and 5.8 S-internal transcribed spacer sequencing, the strain was identified as Pichia kudriavzevii QC-1. The reaction conditions were optimized to 35 ℃, pH 8.0, rotation speed 200 rpm, and 6:5 mass ratio of glucose to 4-hydroxy-2-butanone. Evaluation of the effects of 4-hydroxy-2-butanone concentrations on yield and cell survival rate showed that 85.60 g·L^-1 product accumulated, with an enantiomeric excess of more than 99%, when 30 g·L^-14-hydroxy-2-butanone was added at 0, 10, and 30 h in a 3-L bioreactor. Thus, strain QC-1 showed excellent catalytic activity and stereoselectivity for the synthesis of(R)-1,3-butanediol from 4-hydroxy-2-butanone.展开更多
As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-...As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-HPBE is a biocatalyst that efficiently reduces ethyl 2-oxo-4-phenylbutanoate(OPBE)with high R-enantiose-lectivity.This paper proposed a strategy for identifying key residues involved in enantioselectivity control based on per-residue free energy decomposition and sequence conservatism analysis.Using this strategy,4 noncon-servative sites with high energy contribution to binding of OPBE were chosen as engineering targets,generating variant Mu27 with 99%conversion and 98%(R)ee value at substrate loading of up to 500 mmol/L.MD simu-lations suggested the higher stability and formation probability of Mu27-OPBEproR prereaction state as key rea-sons for the excellent R-enantioselectivity of Mu27 towards OPBE.The success in this study provides a viable approach for rational design of alcohol dehydrogenases with high enantioselectivity towards unnatural substrates.展开更多
Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl)ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-(4"-hydroxy-3",5"- named isatidifoliumindolinones A-D (1-4), were isolated from an...Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl)ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-(4"-hydroxy-3",5"- named isatidifoliumindolinones A-D (1-4), were isolated from an aqueous extract of lsatis indigotica leaves (da qing ye). Their structures including absolute configurations were determined by spectroscopic data analysis combined with comparison of their experimental CD and calculated ECD spectra. Validity of the ECD spectra calculation to assign the absolute configurations is discussed. Plausible biosynthetic pathways of 1-4 are proposed. Stereochemistry-dependent activity against LPS-induced NO production in BY2 cells was observed, and among the stereoisomers compound 4 is most active.展开更多
基金Financial supports from the National Key R&D Program of China(2018YFC1604100)the National Natural Science Foundation of China(NSFC)[21676120,31872891]+8 种基金the 111 Project[111-2-06]the Highend Foreign Experts Recruitment Program[G20190010083]the Program for Advanced Talents within Six Industries of Jiangsu Province[2015-NY007]the National Program for Support of Top-notch Young Professionalsthe Fundamental Research Funds for the Central Universities[JUSRP51504]the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education InstitutionsTop-notch Academic Programs Project of Jiangsu Higher Education Institutionsthe Jiangsu Province“Collaborative Innovation Center for Advanced Industrial Fermentation”Industry Development Programthe National First-Class Discipline Program of Light Industry Technology and Engineering[LITE2018-09]。
文摘(R)-1,3-butanediol is an important pharmaceutical intermediate, and the synthesis of(R)-1,3-butanediol using green biological methods has recently been of interest for industrial application. Here, a novel strain QC-1 that efficiently transforms 4-hydroxy-2-butanone to(R)-1,3-butanediol was isolated from soil samples. Based on morphological, physiological, and biochemical tests and 5.8 S-internal transcribed spacer sequencing, the strain was identified as Pichia kudriavzevii QC-1. The reaction conditions were optimized to 35 ℃, pH 8.0, rotation speed 200 rpm, and 6:5 mass ratio of glucose to 4-hydroxy-2-butanone. Evaluation of the effects of 4-hydroxy-2-butanone concentrations on yield and cell survival rate showed that 85.60 g·L^-1 product accumulated, with an enantiomeric excess of more than 99%, when 30 g·L^-14-hydroxy-2-butanone was added at 0, 10, and 30 h in a 3-L bioreactor. Thus, strain QC-1 showed excellent catalytic activity and stereoselectivity for the synthesis of(R)-1,3-butanediol from 4-hydroxy-2-butanone.
基金This study is financially supported by the National Key Research and Development Program of China(No.2018YFA0901800 to H.Yu and L.Ye)Zhejiang Provincial Natural Science Foundation of China(No.LY18B060001 to L.Ye and No.LZ20B060002 to H.Yu)Natural Science Foundation of China(No.21776244 to H.Yu).We are grateful to the constructive suggestions from academician Fen-Er Chen(Department of Chemistry,Fudan University,Shanghai,China)and the support of Discovery Studio software from Fuzhou University platform.
文摘As an important building block for the synthesis of angiotensin-converting enzyme inhibitors,ethyl(R)-2-hy-droxyl-4-phenylbutanoate[(R)-HPBE]has attracted increasing attention.The key to industrial biosynthesis of(R)-HPBE is a biocatalyst that efficiently reduces ethyl 2-oxo-4-phenylbutanoate(OPBE)with high R-enantiose-lectivity.This paper proposed a strategy for identifying key residues involved in enantioselectivity control based on per-residue free energy decomposition and sequence conservatism analysis.Using this strategy,4 noncon-servative sites with high energy contribution to binding of OPBE were chosen as engineering targets,generating variant Mu27 with 99%conversion and 98%(R)ee value at substrate loading of up to 500 mmol/L.MD simu-lations suggested the higher stability and formation probability of Mu27-OPBEproR prereaction state as key rea-sons for the excellent R-enantioselectivity of Mu27 towards OPBE.The success in this study provides a viable approach for rational design of alcohol dehydrogenases with high enantioselectivity towards unnatural substrates.
基金supported by national 863 project(Grant No.2004AA625030,2001AA620503)NNSFC(Grant No.20432030)Key Innovative Project of the Academy(Grant No.KZCX3-SW-215).
基金Financial support from the National Natural Science Foundation of China (NNSFCNos.81630094,81373287,and 30825044)
文摘Two pairs of unusual scalemic enantiomers with a dimethoxyphenyl)ethyl]-2-methoxyindolin-3-one, novel carbon skeleton of 2-[1′-(4"-hydroxy-3",5"- named isatidifoliumindolinones A-D (1-4), were isolated from an aqueous extract of lsatis indigotica leaves (da qing ye). Their structures including absolute configurations were determined by spectroscopic data analysis combined with comparison of their experimental CD and calculated ECD spectra. Validity of the ECD spectra calculation to assign the absolute configurations is discussed. Plausible biosynthetic pathways of 1-4 are proposed. Stereochemistry-dependent activity against LPS-induced NO production in BY2 cells was observed, and among the stereoisomers compound 4 is most active.