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1814194 
Journal Article 
Hydroperoxidase Activity of Lipoxygenase: A Potential Pathway for Xenobiotic Metabolism in the Presence of Linolenic Acid 
Kulkarni, AP; Cook, DC 
1988 
1 
Research Communications in Chemical Pathology and Pharmacology
ISSN: 0034-5164 
NIOSH/00183176 
61 
3 
305-314 
The ability of soybean lipoxygenase to cooxidize xenobiotic compounds was studied in-vitro. Soybean lipoxygenase was incubated with guaiacol (489861) in the presence of linolenic-acid over the pH range 6.0 to 9.0. The rate of oxidation was followed by measuring oxygen consumption and the amount of tetraguaiacol formed. Similar experiments were conducted with boiled lipoxygenase or in the presence of nordihydroguaiaretic-acid (NDGA), an inhibitor of lipoxygenase. Tetramethyl-p-phenylenediamine (100221) (TMPD), tetramethylbenzidine (366290) (TMB), benzidine (92875), dimethoxybenzidine (119904) (DMB), p-phenylene-diamine (106503) (PPD), or 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic-acid) (30931670) (ABTS) were incubated with soybean lipoxygenase and linolenic-acid and the extent of cooxidation and hydroperoxidase activity were determined as before. Maximum formation of tetraguaiacol occurred at pH 9.0. The amount of tetraguaiacol formed depended on the amount of lipoxygenase and the concentrations of guaiacol and linolenic-acid used. Consumption of oxygen did not depend on the concentration of guaiacol. Boiled lipoxygenase had no hydroperoxidase activity. NDGA inhibited formation of tetraguaiacol in a dose dependent manner. TMPD, TMB, benzidine, DMB, PPD, and ABTS were all cooxidized by lipoxygenase and linolenic-acid. Lipoxygenase had the greatest hydroperoxidase activity toward DMB and the least toward benzidine. The authors conclude that the hydroperoxidase activity of soybean lipoxygenase has a wide substrate specificity and may be a potential pathway of xenobiotic oxidation. 
DCN-171978; In vitro studies; Agricultural products; Enzyme activity; Oxidative processes; Oxygen uptake; Fatty acids; Biotransformation; Organic compounds