alpha-glucosidase inhibitors from clove (Syzgium aromaticum)

The ellagitannins, casuarictin and eugeniin, were isolated as rat intestina l maltase inhibitors from Materials and Methods methanol extracts of clove (Syzgium aromaticum). Eugeniin showed inhibitory activity with an IC50 valu e of 10(-3) m. A structure-activity relationship study among the isolates a nd their related compound, penta-O-galloyl-beta-D-glucose, indicates that a n increasing number of galloyl units in the molecule might lead to an incre ase in the inhibitory activity. Eugeniin also inhibited maltase activity to ward the human intestinal epithelial cell line, Caco-2.