Discovery of 7,9-Disulfatetrahydroberberine as Novel Lipid-Lowering Agents

[Image: see text] Berberine (BBR), a well-known alkaloid, exhibits various pharmacological activities, especially hypolipidemic activity, which has attracted much interest from medicinal chemists in the past decade. However, little progress was made on the structural modification of BBR for improving lipid-lowering activity, mainly due to its unclear biological target and low safety. In this study, a new scaffold of 7,9-disulfatetrahydroberberine was discovered unexpectedly, provided with extremely low cytotoxicity. Hence, a novel series of highly safe 7,9-disulfatetrahydroberberines were designed, synthesized, and evaluated for their hypolipidemic activities. In order to investigate the significance of the 9-position substituent, another new series of 7-sulfatetrahydroberberines were designed and synthesized. Lipid-lowering experiments showed that among these compounds, 5f exhibited the best lipid-lowering activity based on two cell models, 3T3-L1 cells and HepG2 cells. Compared with the blank control, the inhibition rate of compound 5f against total cholesterol was over 60%, the inhibition rate against triglyceride was over 70%, the inhibition rate against low-density lipoprotein cholesterol was approximately 75%, and the inhibition rate against high-density lipoprotein cholesterol was close to 50%, which were far superior to the positive control BBR. This result also verified the feasibility of the development of BBR as a lipid-lowering drug via disubstituted modification at the 7- and 9-position.