Study On Asymmetric Reduction Of Aromatic Sulfides And Oxidation Of Aromatic Ketones Catalyzed With Pseudomonas Sp.

Purpose: To investigate the biocatalytic process of asymmetric oxidation of aromatic sulfides and reduction of aromatic ketones with pseudomonas species.Method: Thioanisole and 4-chromanone were selected as model substrate for screening by whole-cell biotransformation.The reaction system was optimized in order to construct asymmetric oxidation and reduction process,and the substrate scope was investigated.The bioproducts were characterized by HPLC,NMR,Polarimeter,LC-MS.Results:1.Thioanisole was used as the substrate for screening and the reaction conditions were optimized.The target compounds were obtained with 99% conversion in 99% e.e.at this reaction conditions(10 g/cdw cell density,10 mM substrate concentration,pH=7.0,30 ℃).No over-oxidized products sulfone was produced by extending the reaction time to 48 h.The activity was decreased when 10%(v/v)cosolvents was added.Moreover,chiral sulfoxides were obtained with 54%-99% yield in 63%-99% e.e.by investigating the substrate scope.2.The activity of the asymmetric reduction was discovered with Pseudomonas species by changing the culturing conditions.The target compounds were obtained with 99%conversion in 99% e.e.at this reaction conditions(40 g/cdw cell density,5 mM substrate concentration,pH=8.0,30 ℃).Chroman-4-ol was obtained with 98% conversionin 99%e.e.10%(v/v)propanetriol was used as cosolvents and good for increasing activity.Moreover,chiral alcohols were obtained with 87%-99% yield in 65%-92% e.e.by investigating the substrate scope.Conclusion:1.(R)-chiral sulfoxides were obtained with 54-99% yield in 63-99% e.e.by asymmetric oxidation using whole-cell Pseudomonas monteilii M2013683 when M9 medium was used as culture medium.2.(S)-chiral alcohols was obtained with 87-99% yield in 65-92% e.e.by asymmetric reduction using whole-cell Pseudomonas plecoglossicida ZMU-T06 when LB medium was used as culture medium.