Synthesis and α-glucosidase inhibitory activity of chrysin, diosmetin, apigenin, and luteolin derivatives

Several derivatives have been synthesized from chrysin, diosmetin, apigenin, and luteolin, which were isolated from diverse natural plants. The α-glucosidase inhibitory activity of these compounds was evaluated. The glucosidase inhibitory activity of all derivatives (IC50 < 24.396 μmol/L) was higher compared with that of the reference drug, acarbose (IC50 = 563.601 ± 40.492 μmol/L), and 1-deoxynojirimycin (IC50 = 226.912 ± 12.573 μmol/L). O3′,O7-Hexyl diosmetin (IC50 = 2.406 ± 0.101 μmol/L) was the most potent inhibitor identified. These compounds showed a higher inhibitory ability compared with their precursors except the luteolin derivatives. In general, the inhibitory activity of the synthetic derivatives was enhanced with long alkyl chains at positions 3′, 4′ and 7 of the flavonoid.