| Literature DB >> 3621161 |
J M van Maanen, J de Vries, D Pappie, E van den Akker, V M Lafleur, J Retèl, J van der Greef, H M Pinedo.
Abstract
The antitumor agent VP-16-213 is oxidatively O-demethylated by rat liver microsomes and purified rat liver microsomal cytochrome P-450. 3-Methylcholanthrene can quantitatively induce O-demethylation of VP-16-213. The Km and Vmax values for O-demethylation by noninduced, phenobarbital-, and 3-methylcholanthrene-induced rat liver microsomes were found to be 130, 600, and 160 microM and 8.5, 11.8, and 15.6 nmol H2CO/min X mg protein, respectively. Mass spectrometric comparison of the product of O-demethylation of VP-16-213 with the synthetic metabolite resulted in identification of the orthodihydroxy derivative. In studies on the biological activity of the orthodihydroxy derivative, it was found to inactivate single- and double-stranded phiX174 DNA, to bind to calf thymus DNA and to be highly toxic against chinese hamster ovary cells.Entities:
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Year: 1987 PMID： 3621161
Source DB: PubMed Journal: Cancer Res ISSN： 0008-5472 Impact factor: 12.701