Potent, selective inhibitor of IκB kinase (IKK) β (IC50 = 17.9 nM) that displays > 22-fold selectivity over IKKα and > 550-fold selectivity over other kinases and enzymes. Inhibits production of pro-inflammatory cytokines in vitro and in vivo and inhibits NF-κB nuclear localization. Reduces the severity and onset of collagen-induced arthritis; anti-inflammatory. Purity 97%. MW (observed): 279.29