Synthesis and structure–activity relationships of serotonin derivatives effect on α-glucosidase inhibition

The α-glucosidase inhibitory activities of serotonin derivatives were evaluated. Two serotonin derivatives, N-p-coumaroyl serotonin (2) and N-caffeoyl serotonin (4) exhibited most potent inhibition on α-glucosidase, whereas, cinnamic acid derivatives were less efficient. Furthermore, we analyzed their structural importance for α-glucosidase inhibition. The linkage of cinnamic acid moiety and serotonin moiety and the olefin in cinnamic acid moiety of serotonin derivatives were crucial for α-glucosidase inhibition. This is the first report on structure–activity relationships (SAR) for the α-glucosidase inhibitory activity of serotonin derivatives.