A broad spectrum anticancer nucleoside with selective toxicity against human colon cells in vitro

2′,3′-Bis-O-tert-butyldimethylsilyl-5′-deoxy-5′-[N-(methylcarbamoyl)amino]-N⁶-(N-phenylcarbamoyl)adenosine, a new member of the N⁶,5′-bis-ureidoadenosine class of anticancer nucleosides, is found to exhibit broad spectrum antiproliferative activity. A majority of the cell lines in the NCI-60 are inhibited with an average GI₅₀ = 3.13 μM. Selective toxicity against human colon cancer cell lines (COLO 205, HCC-2998, HCT-116, HT29, KM12) was also exhibited (LC₅₀’s = 6-10 μM).