Labelled Genistein (G350000). Exhibits specific inhibitory activity against tyrosine kinases,including autophosphorylation of epidermal growth factor receptor kinase (IC50 - 2.6uM). Also inhibits other protein kinases through competitive inhibition of ATP. Inhibits tumor cell proliferation and induces tumor cell differentiation. Produces cell-cycle arrest and apoptosis in Jurat T-leukemia cells. However, it prevents anti-CD3 monoclonal antibody-induced thymic apoptosis. Genistein also inhibits topoisomerase II activity in vitro. Genistein has also been shown to inhibit the action of GABA on recombinant GABAA receptors 2. uv(max)ethanol: 262.5 nm (e= 138). moderately sol. in hot alcohol