Microsomal chemiluminescence of benzo[ a]pyrene-7,8-dihydrodiol and its synthetic analogues trans- and cis-1-methoxyvinylpyrene

• Published in: Biochimica et biophysica acta. General subjects Vol. 882; no. 2; pp. 210 - 219
• Main Authors: Thompson, Ambler, Biggley, W.H., Posner, G.H., Lever, J.R., Seliger, H.H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 19.06.1986
• Subjects: Benzo[ a]pyrene analog; Chemiluminescence; Dioxetane; Methoxyvinylpyrene; Microsome; Methoxyvinylpyrene; c- and t-MVP, cis- and trans-1-(2′-methoxyvinyl)pyrene; Chemiluminescence; Benzo[ a]pyrene analog; diol epoxide, 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[ a]pyrene; Dioxetane; Microsome; 7,8-diol, trans-7,8-dihydroxy-7,8-dihydrobenzo[ a]pyrene
• ISSN: 0304-4165; 1872-8006
• DOI: 10.1016/0304-4165(86)90157-1

The cis- and trans-methoxyvinylpyrene (MVP) analogues of benzo[ a]pyrene-7,8-dihydrodiol (7,8-diol) produce specific microsomal chemiluminescence comparable to that produced from 7,8-diol in Aroclor-induced rat liver microsome preparations. The chemiluminescence quantum yields, emission spectra, and the concentration and the temporal kinetics of these three substrates have been examined. Radiolabelled 7,8-diol and t-MVP exhibit significant covalent binding (more than 14%) to microsomal protein when metabolized enzymatically. The extreme quenching of the dioxetane chemiluminescence by both microsomes and phosphatidylcholine, as a model phospholipid, implies that despite the low quantum yield (approx. 10 −8 photons per substrate molecule) for microsomal chemiluminescence of these substrates, a significant fraction of their microsomal oxygenations may proceed via a dioxetane pathway.