One-step production of picolinic acids from 2-aminophenols catalyzed by 2-aminophenol 1,6-dioxygenase

Abstract

Picolinic acids have been synthesized previously from catechols by the action of catechol 2,3-dioxygenase and a subsequent chemical reaction in the presence of ammonia. 2-Aminophenol 1,6-dioxygenase catalyzes ring cleavage of several ortho-aminophenols. The ring fission products spontaneously convert to picolinic acids. Resting cells of Escherichia coli DH5α/pNBZ14 harboring the genes for 2-aminophenol 1,6-dioxygenase converted 2-aminophenol and 6-amino-m-cresol to picolinic acid and 5-methylpicolinic acid with yields greater than 90%. The results provide a convenient strategy for the synthesis of substituted picolinic acids from the corresponding aminophenols.