Streptonigrin is a phenylpyridylquinoline originally isolated from S. flocculus with diverse biological activities.1,2,3,4,5,6 Streptonigrin (2.5-12.5 μM) induces DNA cleavage by calf thymus topoisomerase II in a concentration-dependent manner.1 It induces phage production in S. typhimurium when used at concentrations ranging from 1 to 10 μg/ml.2 Streptonigrin (10 μg/ml) inhibits DNA synthesis in and reduces survival of S. typhimurium bacteria. Streptonigrin is bactericidal against E. coli in an iron-dependent manner, an effect that is blocked by the iron chelators deferoxamine and orthophenanthroline.3 Streptonigrin (40 nM) is cytotoxic to human HT-29 colon carcinoma cells but not to BE colon carcinoma cells in which NAD(P)H:quinone oxidoreductase is not expressed.4 Streptonigrin (0.001-0.1 μg/ml) inhibits mitosis and induces chromatin breaks in human leukocytes in a concentration-dependent manner.5 In vivo, streptonigrin (0.05 mg/kg, i.p.) increases the mean survival time in rats infected with Rauscher virus.6
1.Yamashita, Y., Kawada, S., Fujii, N., et al.Induction of mammalian DNA topoisomerase II dependent DNA cleavage by antitumor antibiotic streptonigrinCancer Res.50(18)5841-5844(1990) 2.Levine, M., and Borthwick, M.The action of streptonigrin on bacterial DNA metabolism and on induction of phage production in lysogenic bacteriaVirology21(4)568-574(1963) 3.Yeowell, H.N., and White, J.R.Iron requirement in the bactericidal mechanism of streptonigrinAntimicrob. Agents Chemother.22(6)961-968(1982) 4.Beall, H.D., Liu, Y., Siegel, D., et al.Role of NAD(P)H:quinone oxidoreductase (DT-diaphorase) in cytotoxicity and induction of DNA damage by streptonigrinBiochem. Pharmacol.51(5)645-652(1996) 5.Cohen, M.M., Shaw, M.W., and Craig, A.P.The effects of streptonigrin on cultured human leukocytesProc. Natl. Acad. Sci. USA50(1)16-24(1963) 6.McBride, T.J., Oleson, J.J., and Woolf, D.The activity of streptonigrin against the Rauscher murine leukemia virus in vivoCancer Res.26(4)727-732(1966)