Table 2.
SAR analysis of berberine (1), coptisine (2), palamatine (3), epiberberine (4), and jatrorrhizine (5).
R1 | R2 | R3 | R4 | R5 | R6 | |
---|---|---|---|---|---|---|
1 | -CH2- | H | OMe | OMe | H | |
2 | -CH2- | H | -OCH2O- | H | ||
3 | Me | Me | H | OMe | OMe | H |
4 | Me | Me | H | -OCH2O- | H | |
5 | Me | H | H | OMe | OMe | H |
The methylene-dioxy groups at C2, C3, C9, and C10 showed anti hyperglycemic and antihyperlipidemic effects. These groups are shown in the compounds berberine (1) and coptisine (2) and explained why these two compounds have good antihyperglycemic effects. Meanwhile, the oxidized form of methylene-dioxy group (-OCH2O-) on epiberberine (4) exerts inhibitory activity on aldose reductase (AR) [27].