Exposure of α-tocopherol (I) to NO under aerobic conditions resulted in a complex oxidn. process whose final outcome was dictated by the nature of the reaction medium. In a cyclohexane soln., a prevailing route led to a mixt. of relatively unstable polar products pos. to Griess reagent. On standing at room temp. these were partially converted to a recently described novel 2,3-dimethyl-4-acetyl-4-hydroxy-5-nitroso-2-cyclopentanone deriv. Reaction of I via a secondary oxidn. path led to the formation of α-tocopherylquinone (II) as well as of little amts. of the corresponding nitrite ester. A quite different product pattern was obsd. when the reaction was carried out on a suspension of I in 0.1M phosphate buffer, pH 7.4. In addn. to a significant formation of II and its nitrite ester, product anal. revealed a characteristic pattern of apolar compds. consisting of a yellow dimer and a series of related oligomers. These results provide an improved chem. background to inquire into the role of I in nitric oxide-induced tissue injury
Nitric oxide-induced oxidation of α-tocopherol
d'Ischia M.;
1996
Abstract
Exposure of α-tocopherol (I) to NO under aerobic conditions resulted in a complex oxidn. process whose final outcome was dictated by the nature of the reaction medium. In a cyclohexane soln., a prevailing route led to a mixt. of relatively unstable polar products pos. to Griess reagent. On standing at room temp. these were partially converted to a recently described novel 2,3-dimethyl-4-acetyl-4-hydroxy-5-nitroso-2-cyclopentanone deriv. Reaction of I via a secondary oxidn. path led to the formation of α-tocopherylquinone (II) as well as of little amts. of the corresponding nitrite ester. A quite different product pattern was obsd. when the reaction was carried out on a suspension of I in 0.1M phosphate buffer, pH 7.4. In addn. to a significant formation of II and its nitrite ester, product anal. revealed a characteristic pattern of apolar compds. consisting of a yellow dimer and a series of related oligomers. These results provide an improved chem. background to inquire into the role of I in nitric oxide-induced tissue injuryI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
