title: Absolute configuration of 3-hydroxy acids formed by Stenotrophomonas maltophilia: application of multidimensional gas chromatography and circular dichroism spectroscopy.
abstract: The soil bacterium Stenotrophomonas maltophilia was found to transform various long-chain fatty acids selectively into 3-hydroxy fatty acids of shorter chain length. Their chiral evaluation was performed by multidimensional gas chromatography (MDGC) on modified cyclodextrin phase comparing the enantiodistribution of 1,3-diol formed without loss of stereochemical information from a representative microbial product with those of synthetic (3RS)- and (3S)-1,3-diols. Enantiomeric excesses of 84-98% (R) were determined for the microbially produced 3-hydroxy acids. In addition, the CD exciton chirality method was applied to determine their absolute configuration. Derivatization with 9-anthryldiazomethane and 2-naphthoylimidazole led to the required bichromophoric structures. Their CD spectra displayed a positive first Cotton effect around 254 nm and a negative second Cotton effect around 237 nm, which confirmed the (R)-configuration of the bacterial products.
authors.affiliation: Universität Würzburg, Lehrstuhl für Lebensmittelchemie, Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Weil
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Humpf
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.forename: Peter
authors.initials: P
authors.lastname: Schreier
mesh_terms: D001711:Biotransformation; D002849:Chromatography, Gas / Q000379:methods; D002942:Circular Dichroism; D006880:Hydroxy Acids / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D020615:Stenotrophomonas maltophilia / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D006880:Hydroxy Acids