An imidazole nucleoside with immunosuppressive properties; inhibits T cell proliferation in response to various mitogenic stimuli by 10-100% (1-50 μg/mL); inhibits proliferation of stimulated T cells (IC50 = 5 μg/ml); inhibits guanine nucleotide formation in T cells, reducing GTP pools by 40-60% (5 μg/ml); inhibits replication of HCV RNA in vitro (IC50 = 100 μM); suppresses glomerulosclerosis, urinary albumin excretion, interstitial fibrotic lesions, and macrophage infiltration into glomeruli and the interstitium in a rat model of type 2 diabetes (5 or 10 mg/kg)