Synthesis of Gallic Acid and Pyrogallol from Glucose: Replacing Natural Product Isolation with Microbial Catalysis

Abstract

Among a spectrum of uses, 1 gallic acid and pyrogallol are often incorporated into chemical syntheses to provide the trihydrox-ylated aromatic ring of biologically active molecules such as the antibiotic trimethoprim 1 , the muscle relaxant gallamine tri-ethiodide 2 , and the insecticide bendiocarb 3 . The availability of gallic acid is restricted by its current isolation from insect carapices (gall nuts) harvested in China, and an isolate (tara powder) derived from the ground seed pod of a tree found in Peru. 1 Thermal decarboxylation of gallic acid in copper autoclaves affords pyrogallol. 1 As part of a larger effort 2 to supplant isolation of natural products from scarce natural sources, gallic acid and pyrogallol were targeted for microbe-catalyzed synthesis from abundant glucose. In lieu of an elaborated biosynthetic pathway leading to gallic acid, a pathway had to be created. The result is Escherichia coli KL7/pSK6.161, which synthesizes 20 g/L of gallic acid in 12% yield from glucose. E. coli RB791 serA :: aroB / pSK6.234 then converts gallic acid into pyrogallol in yields of 93 - 97%

Keywords

Identifiers

DOI

10.1021/JA000853R

Journal

Journal of the American Chemical Society

Year

2000