Bioactivity and Chemical Constituents of Different Polar Parts from Blueberry Leaves / 中国药学杂志

ABSTRACT

OBJECTIVE: To study the bioactivity and chemical constituents of different polar parts from blueberry leaves. METHODS: Blueberry leaves were extracted by ethanol and then the extract was sequentially partitioned into five fractions. Silicagel and Sephadex LH-20 chromatographic methods were applied to isolate and purify compounds. Their structures were elucidated by physiochemical properties and spectral analysis.The DPPH• radical scavenging activity, α-glycosidase and pancreatic lipase inhibition activity of different polar parts and partial compounds were determined. RESULTS: The n-butyl alcohol fraction(BF) showed the highest DPPH• radical scavenging activity and α-glycosidase inhibition activity. The ethyl acetate fraction(EAF) showed the strongest pancreatic lipase inhibition activity. A total of five compounds were isolated from the EAF, and their structures were identified as β-sitosterol(1), quercetin-3-O-α-L-arabinofuranoside(2), quercetin(3), quercetin-3-O-β-D-glucopyranoside(4) and 1-O-caffeoylquinic acid(5). A total of two compounds were isolated from the BF, and their structures were identified as quercetin-3-O-α-L-arabinoside(6) and quercetin-3-O-β-D-glucuronide(7). The results showed that compounds 3 and 5 had very good DPPH• radical scavenging and pancreatic lipase inhibitory activity, and compounds 1 and 3 had good α-glucosidase inhibitory activity. CONCLUSION: The different polar parts and compounds of blueberry leaves show strong DPPH• radical scavenging activity, α-glycosidase and pancreatic lipase inhibition activity. Compounds 1, 2, 5 and 6 are isolated from blueberry leaves for the first time.