An antineoplastic agent; inhibits DNA replication and cell proliferation and induces cell cycle arrest in the G1/S phase; inhibits proliferation of NCI H460 human lung cancer cells in vitro (IC50 = 0.56 mM); reduces RNR activity by 75% when used at a concentration of 5 mM via degradation of its active site tyrosyl radical; reduces leukocyte adhesion and extravasation in a humanized mouse model of SCD via NO production and a cGMP-dependent pathway; inhibits HIV-1 viral replication in PBMCs (IC90 = 0.4 mM),