A novel and highly regioselective biocatalytic approach to acetylation of helicid by using whole-cell biocatalysts in organic solvents

Abstract A whole microbial-cell biocatalytic approach was applied in the highly efficient and regioselective acylation of helicid with fatty acid vinyl esters for the first time. Pseudomonas aeruginosa GDM 1.443 displayed the highest conversion and initial rate among the microbial strains tested. Under the optimal operating conditions, the initial reaction rate was 3.4 mM/h, whereas the substrate bioconversion and regioselectivity were 99%. Moreover, an array of 6′-esters of helicid were synthesized with excellent conversion rates and regioselectivities. The reaction rate varies extensively with varying acyl donors because of differential interactions with the enzyme catalytic site. Conclusively, the newly developed route might offer a high potential for helicid fatty acid esters formation.