1-Methylxanthine

1-Methylxanthine is a caffeine derivative. 1-Methylxanthine is an essential human urinary metabolite of caffeine and theophylline (1,3-dimethylxanthine, TP) . 1-Methylxanthine enhances the radiosensitivity of tumor cells. (In Vitro) :1-Methylxanthine exhibits similar activities to other naturally occurring methylxanthines. Unlike caffeine and theobromine, 3-Methylxanthine, and 1-methylxanthine do not occur naturally at high levels in plants. 1-Methylxanthine (3 mM; for 30 min) increases the radiation-induced clonogenic and apoptotic cell (RKO human colorectal cancer cells carrying wild type protein 53 kDa (p53) ) death.