omega-Hydroxylation of Z9-octadecenoic, Z9,10-epoxystearic and 9,10-dihydroxystearic acids by microsomal cytochrome P450 systems from Vicia sativa

Biochem Biophys Res Commun. 1992 Apr 15;184(1):183-93. doi: 10.1016/0006-291x(92)91176-q.


A microsomal fraction from etiolated Vicia sativa seedlings incubated aerobically with [1-14C]oleic acid (Z9-octadecenoic acid) or [1-14C]9,10-epoxystearic acid or [1-14C]9,10-dihydroxystearic acid catalyzed the NADPH-dependent formation of hydroxylated metabolites. The chemical structure of compounds formed from oleic, 9,10-epoxystearic or 9,10-dihydroxystearic acids was established by gas chromatography/mass spectra analysis to be 18-hydroxyoleic acid, 18-hydroxy-9,10-epoxystearic acid and 9,10,18-trihydroxystearic acid, respectively. The reactions required O2 and NADPH and were inhibited by carbon monoxide. As expected for monooxygenase reactions involving cytochrome P450, inhibition could be partially reversed by light and all three reactions were inhibited by antibodies raised against NADPH-cytochrome P450 reductase from Jerusalem artichoke. The omega-hydroxylation of the three substrates was enhanced in microsomes from clofibrate induced seedlings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Radioisotopes
  • Chromatography, High Pressure Liquid
  • Cytochrome P-450 Enzyme System / metabolism*
  • Darkness
  • Gas Chromatography-Mass Spectrometry
  • Hydroxylation
  • Kinetics
  • Light
  • Microsomes / enzymology*
  • Mixed Function Oxygenases / metabolism*
  • Oleic Acid
  • Oleic Acids / metabolism*
  • Plants / enzymology*
  • Stearic Acids / metabolism*
  • Substrate Specificity


  • Carbon Radioisotopes
  • Oleic Acids
  • Stearic Acids
  • 9,10-dihydroxystearic acid
  • 9,10-epoxystearic acid
  • Oleic Acid
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases