【摘要】 本实验主要采用不同溶剂提取苦荞和甜荞麦粉及麦壳中的总黄酮,比较不同来源的总黄酮的得率、光谱特性及DPPH自由基清除活性。结果显示,丙酮对总黄酮的得率略高于乙醇,而甲醇最低,其中苦荞麦粉中黄酮得率为2.99%±0.13%,甜荞麦粉、苦荞麦壳和甜荞麦壳中黄酮的得率相似,都为1.10%左右。紫外扫描光谱表明,甲醇和乙醇提取的黄酮曲线一致,体现出黄酮的典型特征,而丙酮提取出的化合物未表现出该类化合物的特征。结合化学反应,初步认为苦荞麦粉含有黄酮醇类化合物,苦荞麦壳含有黄酮化合物,而甜荞麦壳和甜荞麦粉中可能含有黄烷酮化合物。用不同溶剂提取得到的不同荞麦麦粉及麦壳中总黄酮,其DPPH自由基清除作用具有相似的效果,清除率从大到小依次是丙酮提取物>乙醇提取物>甲醇提取物。更多还原

【Abstract】 Methanol,ethanol and acetone were used to extract total flavonoids from powder and husks of different cultivars of buckwhent(tartary buckwheat and common buckwheat),respectively.The yield,spectral characteristics and DPPH free radical-scavenging activities of extracted total flavonoids were compared.The results indicated that the extraction rate by acetone is the highest,followed that by alcohol and methanol in turn.Except that the yield of total flavonoids extracted from tartary buckwheat powder is 2.99% ±0.13%,all the yields of total flavonoids extracted from sweet buckwheat powder,sweet buckwheat husk and tartary buckwheat husk are about 1.10%.Ultraviolet scanning spectra of methanol and alcohol extracts are alike,showing typical characteristics of flavonoids,but they are not similar to the spectrum of acetone extract.According to chemical reaction characteristics,it was inferred that:(1) tartary buckwheat powder may contain flavonols;(2) tartary buckwheat husk may contain flavones;(3) and sweet buckwheat powder and its husk may contain flavanones.DPPH free-radical scavenging effects of extracts from powder or husks of different cultivars of buckwheat with different solvents are alike.The DPPH free radical scavenging rates decrease in the following order:acetone>alcohol>methanol.更多还原