NITROAROMATIC BETULIN DERIVATIVES AS REDOX CYCLING AGENTS

We have synthesized nitroaromatic derivatives of triterpenoid betulin (lup-20(29)-ene-3 beta,28-diol), ulin-(28)-5'-(aziridin-1-yl)-2',4'-di nitrobenzoate and betulin-(28)-5'-nitro-2'-furoate. These compounds we re reduced in single-electron way by ferredoxin: NADP(+) reductase and flavocytochrome b(2) at rates comparable with their simple structure analogs. Besides, these compounds were substrates for DT-diaphorase. T heir toxicity to bovine leukemia virus-transformed lamb fibroblast cul ture was partly prevented by antioxidant N,N'-diphenyl-p-phenylene dia mine and desferrioxamine, indicating an involvement of oxidative stres s in their cytotoxicity.