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.
ABSTRACT
AIM: To study the isolation,purification and characterization of Ramulus Mori polysaccharide. METHODS: Ramulus Mori was extracted by boiling water. The raw extract was precipitated fractionally by alcohol deproteinized,passing through DEAE ion exchange cellulose ( DEAE-52) and SephadexG-100,obtained RMPS1 and RMPS2. The composition and characterization of Ramulus Mori polysaccharide were researched by TLC、IR、 GC、HPLC and smith degradation. RESULTS: The molecular weight of RMPS1 and RMPS2 were 5. 8 ? 105 and 6. 5 ? 105; RMPS1was made up of rhammose、arabinose、glucose and galactose with the molarity rate of 1. 08 ∶ 1 ∶ 1. 40 ∶ 1. 57; RMPS2 of rhammose、glucose and galactose with the molarity rate of 11. 38 ∶ 1 ∶ 1. 35. Smith degradation showed that the main linkage form in RMPS1 and RMPS2 was 1→2 and 1→4 glycosidic linkages,But some 1→3 glycosidic linkages also existed in the molecules; infrared spectrum showed that both had the polysaccharide characteristic absorption peaks. CONCLUSION: The structures of RMPS1 and RMPS2 are first determined from Ramulus Mori.