Purity ≥98%. Inhibitor of heat shock protein 90 (Hsp90) chaperone activity, and an analog of geldanamycin. Subsequently inhibits the activity of oncogenic proteins such as p185erbB-2 (IC50 = 31nM), N-ras, Ki-ras and c-Akt. Antitumor in vivo. Also protects neuroprogenitor cells against stress-induced apoptosis at low concentrations (10nM) in vitro. Synonyms: NSC 330507, 17-(Allylamino)-17-demethoxygeldanamycin, Tanespimycin