RI-1 (chemical)
RI-1 is a small molecule that selectively blocks RAD51, a key protein used in repairing DNA through homologous recombination. In many cancers, RAD51 is overproduced, which can help tumors grow and resist chemotherapy and radiation. RI-1 inhibits RAD51 by covalently bonding to it at cysteine 319, disrupting the protein interactions needed for RAD51 filament formation and recombinase activity. Its potency is in the IC50 range of about 5–30 μM. The compound has the formula C14H11Cl3N2O3 and a molar mass of about 361.6 g/mol. Because it weakens DNA repair in cancer cells, RI-1 is studied as a potential cancer drug and as a tool to understand DNA repair mechanisms.
This page was last edited on 2 February 2026, at 13:55 (CET).