%0 Journal Article
%T Unusual oxidative pattern in thermo-oxidation of dry films of cholesterol
%A Medina-Meza
%A I.G.
%A Rodr¨ªguez-Estrada
%A M.T.
%A Lercker
%A G.
%A Soto-Rodr¨ªguez
%A I.
%A Garc¨ªa
%A H.S.
%J Revista mexicana de ingenier¨ªa qu¨ªmica
%D 2011
%I Universidad Aut¨®noma Metropolitana Unidad Iztapalapa
%X formation of cholesterol oxidation products (cops) during dry heating of cholesterol films at 150¡ãc for 48 h was studied. a method based on aminopropyl solid-phase extraction (spe), followed by gc-ms analysis was employed for the identification and quantification of cops. two kinetic runs were performed: 60 min and 48 h of treatment. in the short run (60 min), 7-ketocholesterol and 25-hydroxycholesterol were detected in similar amounts after 30 and 15 min, respectively. oxysterols present in higher amounts in the long run (48 h) were 7¦Â-hydroxycholesterol (12.6 mg/g) and 5,6a-epoxycholesterol (13.4 mg/g). however, compounds whose formation is related to enzymatic oxidation and/or irradiation were detected, as 6-ketocholestanol (3.38 mg/g) and 4¦Â-hydroxycholesterol (2.04 mg/g). 25-hydroxycholesterol (0.12 mg/g) was found after only 1 h, reaching 0.99 mg/g after 48 h of treatment. the results suggest that due to the physical state of cholesterol, the oxidative pattern was changed, favoring unusual routes, such as formation of 4¦Â-oh and 6-keto from breakage of the epoxide ring. regarding 25-hydroxycholesterol, it is assumed that the solid state favored exposure of the side chain, rendering it more susceptible to oxidation.
%K 6-ketocholestanol
%K 4¦Â-hydroxycholesterol
%K 25-hydroxycholesterol
%K cholesterol oxidation
%K thermo-oxidation.
%U http://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1665-27382011000100006&lng=en&nrm=iso&tlng=en