GSTO-IN-2 is a glutathione S-transferase inhibitor with IC 50 s of 3.6, 16.3, and 1.4 μM for GSTA2, GSTM1, and GSTP1-1. In Vitro GSTO-IN-2 is compound 3 in the reference. GSTO-IN-2 shows synergetic effect with chemotherapy drugs against two breast cancer cell lines through the inactivation of GST isozymes. The maximal enhancement of cisplatin-induced inhibition of cell viability is observed at 50 μM GSTO-IN-2, up to 640% against MCF-7 and up to 270% against MDA-MB-231. Viability inhibition of thiotepa is enhanced by GSTO-IN-2 (25 and 50 μM), up to 170-320% against MCF-7 and up to 180-270% against MDA-MB-231.. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 3.6 μM (GSTA2), 16.3 μM (GSTM1), 1.4 μM (GSTP1-1)