Abstract: α-Glucosidase inhibitory activity of different extracts from Syringa oblata Lindl., Prunus serrulata var. lannesiana (Carr.) Rehd., Weigela florida (Bunge) A.DC., Vitex negundo L.var. heterophylla (Franch.) Rehd., Spiraea hirsuta (Hemsl.) Schneid., Kolkwitzia amabilis Graebn.) was evaluated compared with acarbose as positive control in vitro.The result showed that extracts from six kinds of flowers all had α-glucosidase inhibitory activity,which V.negundo ethyl acetate extract (IC₅₀=290.57 μg/mL) and P.serrulata var.lannesiana ethyl acetate extract (IC₅₀=292.72 μg/mL) had the highest activity.They were all higher than that of the positive control acarbose (IC₅₀=1213.38 μg/mL).Among different extracts,inhibitory activity of ethyl acetate extract of S.oblata, P.serrulata var.lannesiana, W.florida and V.negundo were higher than that of n-butanol extract,while n-butanol extract of S.hirsuta and K.amabilis was higher than that of their ethyl acetate extract,and inhibitory activity of petroleum ether extract was the lowest.In addition,the concentration of all extracts showed positive correlation with inhibitory activity,and also showed a certain degree of concentration dependence.

Key words: V.negundo,  P.serrulata, α-glucosidase;Inhibitory activity