6-chloro-2-mercaptoquinazolin-4(3H)-one

SMase-IN-1 (Compound 4) is a bacterial sphingomyelinase enzyme (SMase) inhibitor (IC50 value for B. cereus SMase is 6.43 μM). SMase-IN-1 also inhibits eqBuChE (59.50% inhibition rate at 50 μM concentration). SMase-IN-1 forms a complex with Cu2+ in biometal interactions. SMase-IN-1 reduces B. cereus-induced hemolysis on sheep erythrocytes[1].

[1] Ozturk OK, et al. Quinazoline derivatives as novel bacterial sphingomyelinase enzyme inhibitors. Bioorg Chem. 2025 Jan;154:108079. DOI:10.1016/j.bioorg.2024.108079