Anti-Oxidative Constituents of Ethanol Extract from Buckwheat Seeds by HPLC-Electro-Spray MS

The study investigates major anti-oxidative constituents of ethanol extracts from the seeds of common buckwheat and tartary buckwheat. Ethanol extracts from buckwheat seeds were arranged to react with 1,1-diphenyl-2-picrylhydrazyl （DPPH） free radical. HPLC was used to identify anti-oxidative constituents of the ethanol extracts, and electro-spray MS was used to characterize the structures of these identified anti-oxidative constituents to confirm them. The ethanol extracts of common buckwheat and tartary buckwheat seeds both had DPPH free radical-scavenging effect; HPLC analysis showed that the ethanol extracts of both common buckwheat and tartary buckwheat seeds presented two main anti-oxidation peaks, which correspondingly had same chromatographic retention times and spectral information; electro-spray MS analysis showed that the molecular weights and MS fragmentation patterns of the anti-oxidative constituents in the ethanol extracts from buckwheat seeds were the same as those of rutin and quercetin in the control samples. HPLC- MS/MS was capable of being used to rapidly identify anti-oxidative constituents in the extract of buckwheat seeds, and the main anti-oxidative constituents of buckwheat seed extract were mainly rutin and quercetin, and the anti-oxidative activity of quercetin was higher than that of rutin.

Optimization of enzyme assisted extraction of polysaccharides from pomegranate peel by response surface methodology and their anti-oxidant potential

Objective： To optimize the enzymatic extraction conditions of polysaccharides from pomegranate peel using response surface methodology（RSM）, and invest the anti-oxidant activity of pomegranate peel polysaccharide in vitro for seeking novel biological components used as pharmaceutical products and functional foods.Methods： Effects of enzymolysis time, ratio of water to raw material, and the dosage of cellulase on the extraction yield of pomegranate peel polysaccharide were fully examined by Box-Behnken design of RSM. DPPH radical scavenging activity, hydroxyl radicals scavenging activity, superoxide anion radical scavenging activity, and reducing power assay were measured by microplate reader.Results： The optimal extraction conditions were as follows： enzymolysis temperature 55 °C, pH 5.0,enzymolysis time 88 min, ratio of water to raw material 22：1 mL/g, and dosage of cellulose 0.93%. Under the optimal extraction conditions, the yield of pomegranate peel polysaccharide was（22.31 ± 0.07）%,which was well matched with the predicted value 22.35% of the Box-Behnken design model. Also,pomegranate peel polysaccharide demonstrated appreciable anti-oxidant potential on DPPH（1,1-diphenyl-2-picrylhydrazyl） radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging and reducing power in vitro.Conclusions： An optimized enzymolysis assisted method was proposed for the extraction of pomegranate peel polysaccharide, which can be used as a good anti-oxidant.