ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Chaoping Li,Jintao Hu,Cheng Tang,Zewei Liu,Xia Li,Sijie Liu,Rong Tan
Pickering emulsion has recently received widespread attention since it alleviates the mass transfer limitation between oil/water biphases for efficient interfacial catalysis. However, a convenient strategy to control the emulsification and demulsification, so as to combine the reactivity and recovery of catalytic emulsifiers in Pickering interfacial catalysis, remains challenging to date. Herein, we have developed a thermo-switchable Pickering emulsion which could undergo reversible emulsification and demulsification at its cloud point to realize the thermo-controlled Pickering interfacial catalysis for asymmetric sulfoxidation in water. Thermoresponsive Janus silica nanosheets (JNSs) were thus prepared by decorating a stimuli-responsive poly(N-isopropylacrylamide) (PNIPAAm) brush and a catalytically active chiral salen TiIV complex on the opposite sides of mesosilica nanosheets, respectively. Characterization results suggested their temperature-sensitive wettability switching behaviors which resulted in thermo-switchable emulsification/demulsification in an oil/water biphasic system. The smart JNSs could significantly accelerate the asymmetric sulfoxidation in water at room temperature through the formation of stable oil/water Pickering emulsions and then in situ-demulsified quickly for complete separation upon heating over the cloud point (T > 39 °C). The thermo-switchable emulsification/demulsification approach provided a convenient way to control the reaction and separation of Pickering interfacial catalysis on demand, which should simplify the operation in industrial applications.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Shiyu Wei,Yafei Liu,Jieyu Zhou,Guochao Xu,Ye Ni
Two enantiocomplementary Baeyer-Villiger monooxygenases Ra BVMO and Am BVMO were identified by genome mining for the asymmetric sulfoxidation. Both recombinant BVMOs have optimal pH of 9.0 and temperature of 35 °C. The half-lives of Ra BVMO and Am BVMO at 30 °C were 24.4 and 24.6 h. Ra BVMO and Am BVMO exhibited broad substrate spectrum and could catalyze the oxidization of various compounds including fatty ketones, cyclic ketones, and thioethers. Kinetic parameters analysis revealed that both Ra BVMO and Am BVMO displayed higher catalytic efficiency toward thioanisole than cyclohexanone. As much as 50 mM thioanisole could be completely oxidized by Am BVMO and Ra BVMO with 99% ( R ) and 95% ( S ), respectively. Molecular docking analysis further provides evidence for the complementary enantioselectivity of Ra BVMO and Am BVMO. Our results demonstrate the potential application of the two novel BVMOs in asymmetric synthesis of sulfoxides.
研究领域:
生物化学
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酶学
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有机化学
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DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Tiantian Li,Hongjing Liang,Bin Wu,Dongming Lan,Yunjian Ma,Frank Hollmann,Yonghua Wang
Unspecific peroxygenases (UPOs) represent an emerging class of catalysts for the selective oxyfunctionalisation of C H- and C = C groups. Until now, only a few UPOs have been characterised. In this study, we report a new peroxygenase identified from the Unspecific Peroxygenase Database. The UPO from Agaricus bisporus var. bisporus ( Abvb UPO) has been heterologously expressed in Aspergillus niger and initially characterised with respect to its basic biochemical features. Furthermore, its catalytic properties were evaluated with enzymatic cascade reactions of choline oxidase ( AnChOx ) and Abvb UPO, which the AnChOx provided H 2 O 2 necessary via reductive activation of oxygen in situ . Three types of oxyfunctionalizations, such as hydroxylation of ethylbenzene, epoxidations of styrene and cyclohexene, sulfoxidations of methyl phenyl sulfide and phenyl vinyl sulfide, were successfully achieved. We also investigated the activity of Abvb UPO on fatty acids in some more detail. The experimental results show that Under the above conditions, Abvb UPO had the higher activity for cyclohexene epoxidation and sulfonation of sulfide substrates. The concentration of epoxy cyclohexane was 2.91 mM, and the concentration of methyl phenyl sulfoxide was 3.69 mM. The regioselectivity of Abvb UPO was ω-1 bonds position of linear saturated fatty acid. All in all, Abvb UPO exhibits some interesting differences which may put the basis for further understanding of the factors determining peroxygenase selectivity.
研究领域:
生物化学
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酶学
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生物催化
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DOI
高影响因子
CHEMBIOCHEM
·
2014
·Vol. 15
·期 16
·2443-2449
·
IF 3.06
Yue-Cai Yin,Hui-Lei Yu,Zheng-Jiao Luan,Ren-Jie Li,Peng-Fei Ouyang,Jing Liu,Jian-He Xu
Graphical Catalytic versatility of P450 La MO : A new redox-self-sufficient P450 of the CYP116B subfamily was discovered by data mining. A substrate spectrum study showed that it was a catalytic versatile monooxygenase, mediating oxidation reactions as diverse as hydroxylation, alkene epoxidation, O -dealkyl- ation, sulfoxidation, and even hydration. A new member of the CYP116B subfamily—P450 La MO —was discovered in Labrenzia aggregata by genomic data mining. It was successfully overexpressed in Escherichia coli , purified, and subsequently characterized spectroscopically, and its catalytic properties were assessed. Substrate profiling of the P450 La MO revealed that it was a versatile catalyst, exhibiting hydroxylation and epoxidation activities as well as O -dealkylation and asymmetric sulfoxidation activities. Diverse compounds, including alkylbenzenes, aromatic bicyclic molecules, and terpenoids, were shown to be hydroxylated by P450 La MO . Such diverse catalytic activities are uncommon for the bacterial P450s, and the P450 La MO -mediated stereoselective hydroxylation of inactivated C H bonds—ubiquitous and relatively unreactive in organic molecules—is particularly unusual. The self-sufficient nature of P450 La MO , coupled with its broad substrate range, highlights it as an ideal template for directed evolution towards various applications.
研究领域:
生物化学
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酶学
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微生物学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Marine Drugs
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2024
·Vol. 22
·期 9
·419
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IF 4.9
Yun-Han Zhang,Ya-Ting Zou,Yong-Yi Zeng,Lan Liu,Bi-Shuang Chen
This study explores the reasons behind the variations in the enantioselectivity of the sulfoxidation of methyl phenyl sulfide by marine-derived vanadium-dependent haloperoxidases (VHPOs). Twelve new VHPOs of marine organisms were overexpressed, purified, and tested for their ability to oxidize sulfide. Most of these marine enzymes exhibited nonenantioselective behavior, underscoring the uniqueness ofAnVBPO from the brown seaweedAscophyllum nodosumandCpVBPO from the red seaweedCorallina pilulifera, which produce (R)- and (S)-sulfoxides, respectively. The enantioselective sulfoxidation pathway is likely due to direct oxygen transfer within the VHPO active site. This was demonstrated through molecular docking and molecular dynamics simulations, which revealed differences in the positioning of sulfide withinAnVBPO andCpVBPO, thus explaining their distinct enantioselectivities. Nonenantioselective VHPOs probably follow a different oxidation pathway, initiating with sulfide oxidation to form a positively charged radical. Further insights were gained from studying the catalytic effect of VO43−on H2O2-driven sulfoxidation. This research improves the understanding of VHPO-mediated sulfoxidation and aids in developing biocatalysts for sulfoxide synthesis.
研究领域:
生物化学
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海洋生物学
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酶学
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分子生物学
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DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
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2017
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IF 3.33
Chao Shen,Jun Qiao,Linwei Zhao,Kai Zheng,Jianzhong Jin,Pengfei Zhang
A new type of silica supported Chitosan@vanadium complex was used as a highly active heterogeneous catalyst for asymmetric oxidation of aryl alkyl sulfides. With the economic aqueous H 2 O 2 (30%) as the oxidant, the oxidation products were obtained in high yields (up to 95%) with good enantioselectivities (up to 68% ee). It is noted that the marketed drug Nexium (first proton-pump inhibitor, esomeprazole) could be synthesized easily by the newly developed asymmetric sulfoxidation reaction. In addition, the highly active catalyst can be reused five times without losing its catalytic activity.
研究领域:
催化
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有机化学
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药物化学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Yan Zhang,Yin-Qi Wu,Na Xu,Qian Zhao,Hui-Lei Yu,Jian-He Xu
Enzymatic asymmetric sulfoxidation using molecular oxygen as the oxidant is a promising green chemistry approach to chiral sulfoxide production. Despite the broad substrate spectrum of cyclohexanone monooxygenases (CHMOs), some unnatural substrates with bulky functional groups, such as the pharmaceutically relevant omeprazole sulfide, cannot be effectively accepted by CHMOs. Herein, we describe a set of variants derived from an Acinetobacter calcoaceticus CHMO (AcCHMO), whose active sites adjacent to the substrate tunnel were altered to shift the substrate specificity from cyclohexanone monooxygenation toward omeprazole sulfide sulfoxidation. We performed homologous modeling and molecular docking to identify key residues that might affect the substrate specificity. Two libraries of residues lining the active center of AcCHMO were then constructed and screened by an effective halo-based selection method using the solubility difference between the substrate (omeprazole sulfide) and product (esomeprazole). Functional evaluation of the resultant variants showed that the substrate specificity of AcCHMO was markedly altered from the small natural substrate (cyclohexanone) toward the desired bulky substrate (omeprazole sulfide) despite the extremely poor activity detected even for the best variant, M2 (0.61 U/gprot). The crystal structure of M2 complexed with a flavin adenine dinucleotide (FAD) prosthetic group was determined, which provided insight into the altered substrate specificity. To improve the activity of enzyme M2 toward pharmaceutical precursor omeprazole sulfide, we performed both local and global protein engineering among the two CASTing libraries surrounding FAD+ and NADP+ prosthetic groups and an error-prone PCR library of the full-length AcCHMO. As a result, variant M6 was obtained, giving a 50-fold higher activity compared to M2. This structure-guided protein engineering of AcCHMO provided a promising candidate for converting omeprazole sulfide into (S)-omeprazole using a green biocatalytic method.
研究领域:
生物催化
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酶工程
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药物化学
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绿色化学
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蛋白质结构与功能
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DOI
高影响因子
危险品化学品经营许可证（带存储）