RT Journal Article
SR Electronic
T1 Characterization and mechanism of formation of reactive products formed during peroxidase-catalyzed oxidation of p-phenetidine. Trapping of reactive species by reduced glutathione and butylated hydroxyanisole.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 277
OP 286
VO 27
IS 2
A1 D Ross
A1 R Larsson
A1 K Norbeck
A1 R Ryhage
A1 P Moldéus
YR 1985
UL http://molpharm.aspetjournals.org/content/27/2/277.abstract
AB OFF products of horseradish peroxidase (EC 1.11.1.7)-catalyzed oxidation of p-phenetidine were isolated and reactive species were trapped with reduced glutathione (GSH) and butylated hydroxyanisole (BHA). When BHA was added to a reaction mixture after 5 min, subsequent TLC and mass spectrometric analysis revealed the formation of an adduct of BHA and 4-(ethoxyphenyl)-p-benzoquinone diimine (A). The diimine derivative (A) was unstable and its expected degradation products, 4-(ethoxyphenyl)-p-benzoquinone imine (B) and ammonia, were recovered from the reaction in stoichiometric amounts. Ethanol was an early product of the reaction presumably resulting from radical coupling reactions and its formation agreed with the combined production of A and B, suggesting that this was its sole route of formation. The addition of GSH to a reaction at various times and subsequent TLC and high performance liquid chromatographic analysis revealed the presence of at least seven conjugates. Two conjugates were identified by fast atom bombardment mass spectrometry, one as a mono-GSH conjugate of A and another as a mono-GSH conjugate of B. When purified [14C]B was mixed with [3H]GSH, three conjugates were isolated by high performance liquid chromatography, two of which were tentatively identified as di-GSH conjugates. The conjugates isolated existed in both oxidized and reduced forms which could be easily interconverted by redox processes. The production of such reactive species and their conjugates in vivo may be a useful indicator of peroxidase-catalyzed metabolism.