110657-92-6Relevant academic research and scientific papers
Preparation of fatty acid cholesterol ester hydroperoxides by photosensitized oxidation
El Hafidi,Michel,Bascoul,Crastes De Paulet
, p. 127 - 138 (2007/10/03)
Preparation of fatty acid cholesterol ester hydroperoxides was undertaken with the purpose of evaluating their biological effects on cell growth. Cholesterol stearate, oleate, linoleate and α-linolenate were oxidized using methylene blue as a photosensitizer. The structures of all compounds were established by mass spectrometry and by nuclear magnetic resonance. The photosensitized oxidation of cholesterol oleate gave two hydroperoxide isomers: 9-hydroperoxy-trans-10-octadecenoate, and 10-hydroperoxy-trans-8-octadecenoate. In the case of the cholesterol linoleate, hydroperoxide isomers formed were: 9-hydroperoxy-trans-10, cis-12-octadecadienoate; 10-hydroperoxy-trans-8, cis-12-octadecadienoate; 12-hydroperoxy-cis-9, trans-13-octadecadienoate; 13-hydroperoxy-cis-9, trans-11-octadecadienoate. The oxidation of the cholesterol α-linolenate gave a mixture of six hydroperoxide isomers, at positions 9, 10, 12, 13, 15 and 16 of the fatty acid chain. The photosensitized oxidation of cholesterol stearate produced a formation of hydroperoxide at position 5α of cholesterol. The same hydroperoxide isomers on the fatty acid chain were obtained as described in the literature for the fatty acid methyl esters. Copyright (C) 1999 Elsevier Science Ireland Ltd.
Allylic Hydroperoxide Rearrangement: β-Scission or Concerted Pathway?
Porter, Ned A.,Wujek, Jacqueline Sullivan
, p. 5085 - 5089 (2007/10/02)
The rearrangements of the allylic hydroperoxides derived from oleic acid have been studied.Two hydroperoxides are formed by singlet-oxygen oxidation of oleic acid trans-9-hydroperoxyoctadec-10-enoic acid (5) and trans-10-hydroperoxyoctadec-8-enoic acid (6).These hydroperoxides can be separated by reverse-phase chromatography.Rearrangement of 18O-labeled hydroperoxides (5 or 6) under a 32O2 atmosphere led to no incorporation of 16O into the rearrangement products.Similarly, rearrangement of 16O-labeled hydroperoxides (5 or 6) under a 36O2 atmosphere led to no incorporation of 18O into the rearrangement products.The hydroperoxide 5 rearranges to a mixture of 5 and trans-11-hydroperoxyoctadec-9-enoic acid and alcohols and ketones resulting from Russell termination steps.The results are discussed in terms of a concerted rearrangement of allylic peroxyl radicals proceeding through a five-membered-ring transition state.
