title: omicron-Quinone formation in the biochemical oxidation of the antitumor drug N2-methyl-9-hydroxyellipticinium acetate.
abstract: The activation of N2-methyl-9-hydroxyellipticinium acetate (4) by a peroxidase--H2O2 system leads to the formation of an omicron-quinone (7a). This omicron-quinone is not directly generated from the starting material but through a quinone imine intermediate (6) which is subsequently oxidized. This reaction is highly dependent on pH values. The omicron-quinone 7a is easily protonated (7b), gives an addition product with methanol (9), and is reduced by cysteine. The omicron-quinone 7b has a rather low inhibitory effect against L1210 leukemia cell multiplication but acts as an electron carrier and dramatically augments the oxygen consumption in xanthine oxidase-NADH and rat liver microsomes-NADPH systems.
mesh_terms: D000470:Alkaloids / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D004611:Ellipticines / Q000378:metabolism*; D007939:Leukemia L1210 / Q000378:metabolism; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D011809:Quinones / Q000378:metabolism* / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000470:Alkaloids; D000970:Antineoplastic Agents; D004611:Ellipticines; D011809:Quinones; C027767:elliptinium