Design, synthesis, and structure-activity relationships of novel 4,7,12,12a-tetrahydro-5H-thieno[3',2':3,4]pyrido[1,2-b]isoquinoline and 5,8,12,12a-tetrahydro-6H-thieno[2',3':4,5]pyrido[2,1-a]isoquinoline derivatives as cellular activators of adenosine 5'-monophosphate-activated protein kinase (AMPK)

Abstract

To discover more derivatives with better glucose-lowering efficacy compared with berberine, twenty-three novel compounds with 4,7,12,12a-tetrahydro-5H-thieno[3',2':3,4]pyrido[1,2-b]isoquinoline or 5,8,12,12a-tetrahydro-6H-thieno[2',3':4,5]pyrido[2,1-a]isoquinoline cores were designed, synthesized, and biologically evaluated in vitro in continuation of our previous work on indirect activators of adenosine 5'-monophosphate-activated protein kinase (AMPK). Nine compounds effectively stimulated glucose consumption (>2.3-fold at 10 μM) in L6 myotube cells, and two compounds (4d and 4s) exhibited superior inhibitory activity (<57.6% at 5 μM) compared with berberine on gluconeogenesis in rat primary hepatocytes. Additionally, these compounds significantly up-regulated the phosphorylation of AMPK and its substrate, acetyl-CoA carboxylase (ACC) and slightly decreased the mitochondrial membrane potential in L6 myotube cells.

Keywords: AMPK activators; Adenosine 5′-monophosphate-activated protein kinase; Berberine; T2DM; Tetrahydroberberine.