“…DT-diaphorase has been shown to be an important activating enzyme for bioreductive anti-tumour agents, such as mitomycin C (MMC) (Begleiter et al, 1989;Ross et al, 1993;Mikami et al, 1996), 3-hydroxymethyl-5-aziridinyl-l-methyl-2(1H-indole-4,7-dione)prop-,B-en-a-ol (EO9) (Plumb et al, 1994), diaziquone (Siegel et al, 1990), streptonigrin (Beall et al, 1996) and others (Workman and Stratford, 1993) in many systems. Bioreductive agents require intracellular activation by either two-electronreducing enzymes, such as DT-diaphorase (Ross et al, 1993;Plumb et al, 1994) and xanthine dehydrogenase (EC 1.1.1.204) (Gustafson and Pritsos, 1992) or by one-electron-reducing enzymes, such as NADPH:cytochrome P450 reductase (EC 1.6.2.4) (Pan et al, 1984) and NADH:cytochrome b5 reductase (EC 1.6.2.2) (Hodnick and Sartorelli, 1993).…”