Thioredoxin-1 (Trx-1) inhibitor; irreversibly inactivates Trx-1 as a substrate for reduction by thioredoxin reductase (TR); competitively inhibits the reduction of Trx-1 by TR (Ki = 30.8 μM). Attenuates expression of HIF-1α, VEGF and iNOS (IC50 values are 7.2, 10.4 and 18.1 μM respectively). Exhibits antitumor activity; directly inhibits tubulin in vitro and decreases tumor microvessel density in vivo. Purity 99%. MW (observed): 188.31