PX-478 hydrochloride is an inhibitor of HIF-1α (IC50 of 20-30 μM) with potential antineoplastic activity. PX-478 inhibits HIF-1alpha protein levels and transactivation in a variety of cancer cell lines. The inhibitory effect of PX-478 on HIF-1alpha levels is primarily due to its inhibition of translation because HIF-1alpha translation continues in hypoxia when translation of most proteins is decreased. MW: 394.11. Purity ≥98% by HPLC