Pressurized CO2 as a carboxylating agent for the biocatalytic ortho-carboxylation of resorcinol

The utilization of gaseous carbon dioxide instead of bicarbonate would greatly facilitate process development for enzyme catalyzed carboxylations on a large scale. As a proof-of-concept, 1,3-di-hydroxybenzene (resorcinol) was carboxylated in the ortho-position using pressurized CO2 (similar to 30-40 bar) catalyzed by ortho-benzoic acid decarboxylases with up to 68% conversion. Optimization studies revealed tight pH-control and enzyme stability as the most important determinants.