title: Microbial transformations of p-coumaric acid by Bacillus megaterium and Curvularia lunata.
abstract: p-Coumaric acid (1) is an abundant phenolic natural product that exhibits both chemoprotectant and antioxidant properties. Microbial transformation screening studies showed that 1 was converted to 4-vinylphenol (4), 4-hydroxybenzoic acid (2), caffeic acid (5), protocatechuic acid (6), and other unidentified metabolites over 144 h. 4-Vinylphenol (4) and its dimer, (2R,2S)-4-(2,3-dihydro-5-hyroxy-2-benzofuranyl) phenol (11), were produced by Bacillus megaterium, and 5-[(E)-2-carboxyethenyl]-2,3-dihydro-2-(4-hydroxyphenyl)-3-benzofurancarboxylic acid (15) and 4-hydroxybenzoic acid (2) were produced by Curvularia lunata. On the basis of deuterium-labeling experiments, B. megaterium catalyzes the nonoxidative enzymatic tautomerization of 1 to a vinylogous beta-keto acid intermediate that decarboxylates to 4. The presence of peroxidase and laccase activities in C. lunata extracts suggests that these enzymes may be involved in one-electron, p-coumaric acid dimerization in this organism.
authors.affiliation: Division of Medicinal and Natural Products Chemistry, and Center for Biocatalysis and Bioprocessing, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Torres Y Torres
authors.forename: J P
authors.initials: JP
authors.lastname: Rosazza
mesh_terms: D001410:Bacillus megaterium / Q000201:enzymology / Q000378:metabolism*; D001711:Biotransformation; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003373:Coumaric Acids / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D008401:Gas Chromatography-Mass Spectrometry; D042845:Laccase; D013058:Mass Spectrometry; D003904:Mitosporic Fungi / Q000201:enzymology / Q000378:metabolism*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010088:Oxidoreductases / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: D003373:Coumaric Acids; D010088:Oxidoreductases; D042845:Laccase; D009195:Peroxidase