VR-23

A potent inhibitor of trypsin-like proteasome (IC50=1 nM), chymotrypsin-like proteasome (IC50=50-100 nM) and caspase-like proteasome (IC50=3 uM) ; targets the β2 of the 20S proteasome catalytic subunit and structurally distinct from other known proteasome inhibitors and selectively kills cancer cells by apoptosis, with little effect on noncancerous cells.