https://www.selleckchem.com/products/bemnifosbuvir-hemisulfate-at-527.html Mutations in the isocitrate dehydrogenase 1 (IDH1) gene are frequently found in various cancer types. IDH1 mutants produce 2-hydroxyglutarate (2-HG), an oncometabolite, from alpha-ketoglutarate (α-KG). This 2-HG plays a key role in tumorigenesis via inhibition of α-KG dependent enzymes. For this reason, IDH1 mutant could be an ideal target for the treatment of cancer. To find a new IDH1 inhibitor, 8,364 compounds were obtained from Korea Chemical Bank. Using high-throughput screening (HTS) of a chemical library, we unveiled a compound that could inhibit the IDH1 mutant. According to the enzyme assay, our compound (KRC-09) effectively inhibited the activity of IDH1 R132H mutant. In addition, KRC-09 decreased the concentration of intracellular 2-HG in the U-87 MG cell line harboring IDH1 R132H. In this article, we present a novel chemical scaffold that suppresses the activity of an IDH1 mutant. In this article, we present a novel chemical scaffold that suppresses the activity of an IDH1 mutant. Phenothiazines constitute a versatile family of compounds in terms of biological activity, which have also gained a considerable attention in cancer research. Three phenothiazines (promethazine, chlorpromazine and thioridazine) have been tested in combination with 11 active selenocompounds against MDR (ABCB1-overexpressing) mouse T-lymphoma cells to investigate their activity as combination chemotherapy and as antitumor adjuvants in vitro with a checkerboard combination assay. Seven selenocompounds showed toxicity on mouse embryonic fibroblasts, while three showed selectivity towards tumor cells. Two compounds showed synergism with all tested phenothiazines in low concentration ranges (1.46-11.25 μM). Thioridazine was the most potent among the three phenothiazines. Phenothiazines belonging to different generations showed different levels of adjuvant activities. All the tested phenothiazines are already a