The components with hypoglycemic activity in Plumeria rubra were isolated and purified by various column chromatography techniques and activity tracing methods. The physical and chemical properties of all the purified monomer compounds were characterized and analyzed, and a total of six compounds were isolated and identified, including 6″-acetyl-6-hydroxy-benzyl-benzoate-2-O-β-D-glucoside(1), 6-acetyl-6-hydroxy-benzyl-benzoate-2-O-β-D-glucoside-(1→6″)-β-D-glucoside(2), 2-hydroxy-6-methoxy-benzyl-benzoate-2-O-β-D-glucoside(3), 6-hydroxy-benzyl-benzoate-2-O-β-D-glucoside(4), 6-hydroxy-benzyl-benzoate-2-O-β-D-glucoside-(1→6″)-β-D-glucoside(5), and 6-hydroxy-benzyl-benzoate-2-O-β-D-glucoside-(1→6″)-β-D-xyloside(6). Compounds 1 and 2 were new compounds, and compounds 3-6 were isolated from Plumeria for the first time. The α-glucosidase inhibitory activity of six identified compounds was tested. The results show that compounds 1-6 show certain inhibitory activity with an IC_(50) value ranging from 8.2 to 33.5 μmol·L~(-1).
Keywords: Plumeria rubra; benzyl-benzoate; glucosides; α-glucosidase inhibitory activity.