A standard acute toxicity study was undertaken to assess 2′-deoxyribonucleoside
cyanoboranes for therapeutic safety. 2′-Deoxyribonucleoside cyanoboranes and related
derivatives were nontoxic at doses required for anti-neoplastic and hypolipidemic activities.
At higher doses (50 and 100 mg/kg/day IP for 7 days), all treated animals survived with
slight reductions in total body weight and small decrements in daily food consumption. No
clinical chemistry value was elevated to a magnitude suggesting onset of organ specific
toxicity. However, agents appeared to modulate subpopulations of white blood cells, i.e.¯,
more lymphocytes than PMNs were present in blood from treated animals as determined by
differential cell counts. This modulation is correlated with increases in granulomatous foci in
the spleen and mesentery of treated animals after 7 days. The kidney was damaged only by
Compound 5¯ at 50 and 100 mg/kg/day; Compound 5¯ had the most potent anti-neoplastic
activity. The compounds demonstrated no in vitro¯ toxicity against human HCT-8 ileum cells.
LD50 values were greater than 1000 mg/kg, IP, for all compounds.