Synthesis and antihyperglycemic evaluation of various protoberberine derivatives

Various berberine derivatives (2–17) were synthesized and their antihyperglycemic activities were evaluated in a model of β-cell-membrane chromatography and a model of alloxan-induced diabetes mice. The results indicated that compounds 5 and 14 exhibited antihyperglycemic activity. Their structure–activity relationships were discussed.