title: A novel ortho-dehalogenation reaction of 2-chlorocinnamic acid catalyzed by the pink yeast Rhodotorula rubra Y-1529.
abstract: In the present study, a resting cells suspension of Rhodotorula rubra Y-1529 was shown to have the capacity to perform an ortho-dehalogenation reaction on 2-chlorocinnamic acid. The results from the biodegradation of U-[14C]benzoic acid, cinnamic acid, 3-chlorocinnamic acid and 4-chlorocinnamic acid suggest that the first step of the ortho-dehalogenation reaction occurred during the oxidation of the unsaturated C3 side chain of 2-chlorocinnamic acid to 2-chlorobenzoic acid. None of the 2-chlorobenzoic acid was found in the biodegradation system, suggesting that this step was a highly regulated step. After the side-chain oxidation reaction, the hydroxylation of the benzene ring was determined to be at the para-position first, followed by the meta-position. The occurrence of 3:4-position ring fission reactions and the production of the final product, CO2, was proven by the biodegradation of U-[14C] benzoic acid. This oxidative dehalogenation reaction catalyzed by R. rubra was found to be regiospecific for 2-chlorocinnamic acid; the chloride ion was probably removed after the ring fission reaction. A pathway of the ortho-dehalogenation reaction of 2-chlorocinnamic acid catalyzed by R. rubra was proposed based on these data.
authors.affiliation: Department of Health and Nutrition, Chia Nan College of Pharmacy and Science, Tainan 71710, Taiwan, ROC. pfangmin@chna.chna.edu.tw
authors.forename: F M
authors.initials: FM
authors.lastname: Sun
authors.forename: J S
authors.initials: JS
authors.lastname: Wang
authors.forename: R W
authors.initials: RW
authors.lastname: Traxler
mesh_terms: D019817:Benzoic Acid / Q000737:chemistry / Q000378:metabolism; D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000032:analysis / Q000737:chemistry; D002250:Carbon Radioisotopes; D002384:Catalysis; D002712:Chlorides / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002934:Cinnamates / Q000737:chemistry* / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D017736:Ion-Selective Electrodes; D012248:Rhodotorula / Q000378:metabolism*
chemical_list: D002250:Carbon Radioisotopes; D002712:Chlorides; D002934:Cinnamates; D002245:Carbon Dioxide; C409927:2-chlorocinnamic acid; D019817:Benzoic Acid