We have previously reported compound 2 as a inhibitor of acyl-coenzyme A:cholesterol O-acyltransferase (ACAT) and up-regulator of the low density lipoprotein receptor (LDL-R) expression. In this study we focused on compound 2, a unique LDL-R up-regulator, and describe the discovery of a novel class of up-regulators of LDL-R. Replacement the methylene urea linker in compound 2 with an acylsulfonamide linker kept a potent LDL-R up-regulatory activity, and subsequent optimization work gave compound 39 as a highly potent LDL-R up-regulator (39; EC(25) = 0.047 microM). Compound 39 showed no ACAT inhibitory activity even at 1 microM. The sodium salts of compound 39 reduced plasma total and LDL cholesterol levels in a dose-dependent manner in an experimental animal model of hyperlipidemia. Moreover, we revealed in this study using RNA interference that autosomal recessive hypercholesterolemia (ARH), an adaptor protein of LDL-R, is essential for compound 39 up-regulation of LDL-R expression.