Enantiomeric separation and analysis of unsaturated hydroperoxy fatty acids by chiral column chromatography-mass spectrometry

Chiral Phase-HPLC Separation of Hydroperoxyoctadecenoic Acids and Their Biosynthesis by Fatty Acid Dioxygenases

“…The MS/MS spectra (m/z 313 →full scan) confirmed that HPOME were dehydrated to KOME as judged from the main ion at m/z 295 (313-18) in analogy with dehydration of other hydroperoxy fatty acids (12,24). Important ions in the MS 3 spectra (m/z 313 →295 →full scan) of HPOME are summarized in Tables 2 and 3.…”

“…Fractions (1-2 ml) were collected, and an aliquot (2 µl) of fractions with UV absorbance was analyzed for HPOME by direct injection to the mass spectrometer in a solvent stream (0.3 ml/min) of methanol/water/acetic acid, 800/200/0.1. This method can also be used for separation of stereoisomers of 9-and 13-HPODE obtained by photooxidation of linoleic acid (12), and with UV analysis at 235 nm for detection of HPODE.…”

“…An alternative to cellulose and amylose is an aromatic chiral selector of "Pirkle type", coated on silica (Reprosil Chiral NR (see Note 1). The latter can separate enantiomers of hydroperoxyeicosatetraenoic and hydroperoxyoctadecadienoic acids (12).…”

Catalytic Convergence of Manganese and Iron Lipoxygenases by Replacement of a Single Amino Acid

“…46) or with Chiralcel OBH (Daicel; 4.6 ϫ 250 mm; equipped with a silica guard cartridge) eluted with 95:5:0.1 hexane/isopropyl alcohol/ acetic acid at 0.5 ml/min. Hydroperoxy fatty acids were separated on Reprosil Chiral NR (8 m; 2 ϫ 250 mm; Dr. Maisch GmbH, Ammerbuch, Germany; equipped with a silica guard cartridge) eluted at 0.5 ml/min with 99:1:0.1 hexane/methanol/ acetic acid (45). The effluent from the chiral columns was combined with 3:2 isopropyl alcohol/water from a Surveyor MS pump (0.1-0.25 ml/min) and analyzed on line by MS/MS as described above.…”

A new class of fatty acid allene oxide formed by the DOX-P450 fusion proteins of human and plant pathogenic fungi, C. immitis and Z. tritici

“…Chiral-phase (CP)-HPLC analysis of 8-and 9-HPODE was performed by chromatography on Reprosil Chiral-NR (8 m; 2 × 250 mm; Dr. Maisch), which was eluted at 0.5 ml/min with hexane/ isopropyl alcohol/acetic acid, 98.8/1.2/0.01 (25), and isomers of 8-HODE were resolved on Chiralcel OBH (26). Isomers of HETE and 9-and 13-HODE were resolved on Reprosil Chiral-AM (5 m; 2 × 250 mm; Dr. Maisch), eluted (0.2 ml/min) with hexane/ methanol/acetic acid, 96/4/0.02 or 95/5/0.02.…”