Human ACAT-1 and -2 inhibitory activities of saucerneol B, manassantin A and B isolated from Saururus chinensis

The sesquineolignan, saucerneol B (1), and dineolignans, manassantin A (2), and manassantin B (3), were isolated from the methanol extracts of Saururus chinensis root and elucidated by their spectroscopic data analysis. Compounds 1–3 inhibited hACAT-1 and hACAT-2 with IC50 values of 43.0 and 124.0 μM for 1, of 39.0 and 8.0 μM for 2, of 82.0 μM and only 32% inhibition at 1 mM for 3, respectively. The EtOAc-soluble fraction, which contained compounds 1–3, of methanol extracts of S. chinensis exhibited strong cholesterol-lowering effect in high cholesterol-fed mice.