The cholesteryl ester transfer protein (CETP), inhibition of which assists in maintaining a high level of high-density lipoprotein cholesterol in the blood, is a target for anti-atherosclerosis treatments. Orange monascus pigment was produced by a Monascus species in a 5 L jar fermenter and various derivative compounds were synthesised by incorporating 19 different L-amino acids into the orange pigment. Among them, the L-Thr and L-Tyr derivatives exhibited high inhibitory activities against the CETP reaction. The inhibitory activities of the L-Thr and L-Tyr derivatives increased in a dose-dependent manner, resulting in IC50 values of 1.0 and 2.3 μM, respectively. When CETP reactions in the presence of the derivatives were performed, the inhibition modes of the L-Thr and L-Tyr derivatives were non-competitive with inhibition constant (Ki) values of 2.7 and 4.3 μM, respectively.
Keywords: cholesteryl ester transfer protein (CETP); inhibitory kinetics; monascus pigment derivatives.