As simultaneously inhibiting HDAC-mediated resistance with cisplatin treatment could potentiate the platinum drug’s effect, we first confirmed the anti-cancer effect of compound B in the A2780 and A2780cis cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide spectrophotometric assay. This evidence concerns the gene HDAC9 and cancer.