不同竹种竹叶提取物制备及其抗氧化活性比较研究

以毛竹、苦竹、香竹、箬竹、粉单竹、青杆竹和青皮竹7个竹种竹叶为材料,采用热回流法提取,大孔树脂法分离纯化,对得到竹叶提取物测定其得率和主要黄酮成分的含量,进而探讨竹叶提取物的抗氧化活性,为竹叶提取物在食品和化妆品领域的应用提供科学依据。结果表明,苦竹叶提取物得率最高,为3.60%～3.70%;香竹叶提取物中所含的荭草苷和异荭草苷量最高,为2.523 0%～2.532 6%,苦竹叶提取物中所含的牡荆苷量最高,为0.887 0%～0.889 6%,青杆竹叶提取物中所含的异牡荆苷量最高,为2.223 1%～2.226 1%;竹叶提取物具有较强的自由基清除作用;香竹表现的DPPH自由基清除能力最强,IC50值为30.50 mg·L-1;箬竹的超氧阴离子和羟自由基清除效果最强,IC50值分别为339.32 mg·L-1和324.87 mg·L-1。

Preparation and comparative analysis of antioxidant activity of bamboo leaf extracts from different varieties

Phyllostachys heterocycla,Pleioblastus amaru,Bambusa tuldoides,Bambusa chungii,Bambusa textilis,Chimonocalamus Hsueh and Indocalamus tessellates were used to extract bamboo-leaf-flavonoids by the heat reflux method and purified by AB-8 macroporous absorption resin.The extractions were separated and struc-turally identified by high-performance liquid chromatography(HPLC).The bamboo leaf extracts were assayed based on DPPH radical scavenging capacity,hydroxyl radical scavenging capacity,superoxide anion free radical scavenging capacity,and reducing power with TBHQ(tert-butyl hydroquinone) as the positive control.The results showed that the yield of extracts from Pleioblastus amarus was maximum,up to 3.60%-3.70%;the amount of orientin and isoorientin in Chimonocalamus Hsueh was maximum,up to 2.5230%-2.5326%;the amount of vitexin in Pleioblastus amarus was maximum,up to 0.8870%-0.8896%;the amount of isovitexin in Bambusa textilis was maximum,up to 2.2231%-2.2261%.Chimonocalamus Hsueh revealed the strongest scavenging ca-pacity against DPPH,and the IC50 value was 30.50 mg?L-1;Indocalamus tessellates revealed the strongest scav-enging capacity against hydroxyl radical and superoxide anion free radical,and the IC50 values were 339.32 mg?L-1 and 324.87 mg?L-1,respectively.