Isolation of Isoguanosine from Croton tiglium and Its Antitumor Activity

This paper describes the isolation of isoguanosine from Croton tiglium L. and its cytotoxic effect anginst several tumor cell lines in culture and newly reports that isoguanosine has an antitumor activity against implanted S-180 ascitic turmor mice. Isoguanosine is effective at the dose of $24mg/kg/day{\times}5$, with T/C value of 168%. Isoguanosine inhibits the gorwth of S-180 and Ehrich solid tumor in mice at the optimal doses of $96\; mg/kg/day{\times}12$ and $48\;mg/kg/day{\times}12$, with 1-T/C values of 65% and 60% respecively.