In vitro activity: In Caco-2 cell line, NCT-501 exhibits excellent permeability.

Kinase Assay: NCT-501 is a novel, highly potent and selective inhibitor of Aldehyde Dehydrogenase 1A1 (ALDH1A1) with IC50 of 40 NM. NCTAldehyde dehydrogenases (ALDHs) metabolize reactive aldehydes and possess important physiological and toxicological functions in areas such as CNS, metabolic disorders, and cancers. Increased ALDH (e.g., ALDH1A1) gene expression and catalytic activity are vital biomarkers in a number of malignancies and cancer stem cells, highlighting the need for the identification and development of small molecule ALDH inhibitors.

Cell Assay: For more than 450 human kinases, NCT-501 treatment at 10 μM inhibited ≥55% activity of these kinases. NCT-501 reversibly inhibited ALDH1A1.The plasma exposure for intraperitoneal administration (ip) at 30 mg/kg showed better than the oral administration (p.o) at 30 mg/kg. The values of AUC 24h were 5670 h·ng/mL and 484 h·ng/mL along with 100% and 29% bioavailability, respectively. The t1/2 was shorter than 1h. The clearance level was 98 mL/min/kg. These results together indicated that NCT-501 was well absorbed and distributed but rapidly metabolized or excreted. In vitro stability of NCT-501in CD1 mouse plasma was more than 60 min.