PYRIB-SO 2 is an effective antimitotic (mitotic) agent that exhibits antiproliferative activity and induces cell cycle arrest at the G2/M phase. It disrupts and reduces microtubule structures by binding to the colchicine-binding site (C-BS) on α, β-tubulin.

PYRIB-SO 2 (150 nM; 24 h) induces cell cycle arrest in the G2/M phase. At a concentration of 138 nM over 24 hours, PYRIB-SO 2 disrupts and reduces microtubule structure in MCF7 cells. It also decreases the formation of EBI:β-tubulin adducts at concentrations of 5 and 50 µM.