Quinazoline, enzymic oxidation

Diamine oxidase (DAO) activity could be determined by first reacting cadaverine with an enzyme to produce A1-piperidine, which then was reacted with 2-aminobenzaldehyde and finally chromium(VI) oxide to form 6,7,8,9-tetrahydro-ll//-pyrido[2,l-b]quinazolin-ll-one (7). The latter was determined on an HPLC apparatus (Scheme 5) (84MI4). 

The ability of quinazoline to enter the xanthine oxidase active site, and the presence of an active site nucleophile near the alkylating center, very likely accounts for enzyme inactivation by these hydroquinones. The quinone (696) acts as an oxidizing suicide substrate. It is able to enter the xanthine oxidase active-site, and by the enzyme reductive action and HCl elimination it becomes a reductive alkylating agent (698) targeted towards cellular structures important to the cancer cell <88JOC6099>. 

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