ES 936 is a potent and selective NQO1 inhibitor, inhibiting more than 95% of NQO1 activity within 30 minutes at a concentration of 100 nM, with a cell line-dependent inhibition duration resulting in a small number of DNA strand breaks.

Streptonigrin cytotoxicity in HCT116 cells (with ES936 pretreatment):11 ± 0.6 nM, Cell proliferation in HCT116 cells:569 ± 48 nM, Streptonigrin cytotoxicity in MDA468 NQ-16 cells (without ES936 pretreatment):2.2 ± 0.06 nM, Cell proliferation (reflecting cytotoxicity) in MDA468 NQ-16 cells:732 ± 49 nM, Streptonigrin cytotoxicity in HCT116 cells (without ES936 pretreatment):6.7 ± 1 nM, Streptonigrin cytotoxicity in MDA468 NQ-16 cells (with ES936 pretreatment):13 ± 0.4 nM 

ES 936 在 MDA468 NQ-16（高 NQO1 活性）和 HCT116（低 NQO1 活性）细胞中对细胞增殖的抑制作用较弱，IC₅₀ 分别为 732 ± 49 nM 和 569 ± 48 nM，明显高于其抑制 NQO1 所需的浓度（高出约 8–20 倍），说明其本身细胞毒性较低。[1] 在联合处理实验中，ES 936 预处理可显著升高 Streptonigrin 的 IC₅₀ 值，MDA468 NQ-16 细胞中从 2.2 ± 0.06 nM 提高到 13 ± 0.4 nM（约 6 倍），HCT116 细胞中从 6.7 ± 1 nM 提高到 11 ± 0.6 nM（约 2 倍），说明 ES 936 通过抑制 NQO1 活性，削弱了 Streptonigrin 的代谢活化及其毒性。[1]