Hematin-catalyzed epoxidation of 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene by polyunsaturated fatty acid hydroperoxides.
AuthorsDix TA, Fontana R, Panthani A, Marnett LJ
JournalJ Biol Chem
PubMed ID4039321
'Hematin catalyzes the epoxidation of 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP-7,8-diol) by 13-hydroperoxy-9-cis,11-trans-octadecadienoic acid and other fatty acid hydroperoxides in the presence of detergent. The major oxidation product is the anti-dihydrodiolepoxide and the minor product is the syn-dihydrodiolepoxide. (+)-BP-7,8-diol is oxidized to (-)-anti-diolepoxide and (+)-syn-diolepoxide whereas (-)-BP-7,8-diol is oxidized to (+)-anti-diolepoxide and (-)-syn-diolepoxide. Oxygen ... More
Inhibition of diphenolase activity of tyrosinase by vitamin b(6) compounds.
AuthorsYokochi N, Morita T, Yagi T
JournalJ Agric Food Chem
PubMed ID12696965
The vitamin B(6) compounds pyridoxine (PN), pyridoxamine (PM), pyridoxal (PL), and pyridoxamine 5'-phosphate (PMP) inhibited the diphenolase activity of mushroom tyrosinase. PM showed the highest inhibition; the control activity was inhibited by 38% at 1.5 mM. Each PL, PN, and PMP showed about 30% inhibition at the same concentration. Lineweaver-Burk ... More
Point mutations at the thymidine kinase locus in L5178Y mouse lymphoma cells. II. Test validation and interpretation.
AuthorsAmacher DE, Paillet SC, Turner GN, Ray VA, Salsburg DS
JournalMutat Res
PubMed ID7453708
The L5178Y Mouse Lymphoma TK assay was studied extensively to determine if this mammalian cell assay for gene mutations at the thymidine kinase (TK) locus could provide valid, interpretable determinations of mutagenic potential, and whether this information is of value in the safety evaluation of chemicals. We first determined that ... More
Chlorination of pyridinium compounds. Possible role of hypochlorite, N-chloramines, and chlorine in the oxidation of pyridinoline cross-links of articular cartilage collagen type II during acute inflammation.
AuthorsDaumer KM, Khan AU, Steinbeck MJ
JournalJ Biol Chem
PubMed ID10940296
Reactive oxygen species produced by activated neutrophils and monocytes are thought to be involved in mediating the loss of collagen and other matrix proteins at sites of inflammation. To evaluate their potential to oxidize the pyridinoline (Pyd) cross-links found in collagen types I and II, we reacted hydrogen peroxide (H(2)O(2)), ... More