Affiliation: | (1) Department of Biological Sciences, The University of Warwick, Coventry, CV4 7AL, UK;(2) Present address: Air Force Research Laboratory, MLQL, Building 1117, 139 Barnes Drive, Suite #2, Tyndall AFB, Tyndall AFB, FL 32403, USA;(3) School of Chemistry, The Queens University of Belfast, Belfast, BT9 5AG, UK;(4) Avecia Pharmaceuticals, Belasis Avenue, Billingham, Cleveland, TS23 1YN, UK |
Abstract: | The kinetic resolution of racemic sulfoxides by dimethyl sulfoxide (DMSO) reductases was investigated with a range of microorganisms. Three bacterial isolates (provisionally identified as Citrobacter braakii, Klebsiella sp. and Serratia sp.) expressing DMSO reductase activity were isolated from environmental samples by anaerobic enrichment with DMSO as terminal electron acceptor. The organisms reduced a diverse range of racemic sulfoxides to yield either residual enantiomer depending upon the strain used. C. braakii DMSO-11 exhibited wide substrate specificity that included dialkyl, diaryl and alkylaryl sulfoxides, and was unique in its ability to reduce the thiosulfinate 1,4-dihydrobenzo-2, 3-dithian-2-oxide. DMSO reductase was purified from the periplasmic fraction of C. braakii DMSO-11 and was used to demonstrate unequivocally that the DMSO reductase was responsible for enantiospecific reductive resolution of racemic sulfoxides. |