核桃(Juglandaceae)种仁、叶、花粉抗氧化活性及成分鉴定

为综合开发核桃生物资源,研究了7种不同溶剂提取的不同种类核桃种仁、叶及其花粉提取物的抗氧化活性,并鉴定其抗氧化成分。采用DPPH和ABTS+自由基清除能力以及FRAP还原能力评价其抗氧化活性,并测定总酚、总黄酮含量,采用高分辨质谱仪鉴定样品抗氧化活性成分。结果表明,供试7种溶剂中60%丙酮提取物抗氧化活性较高。山核桃叶的DPPH(IC₅₀=0.156 mg/mL)和ABTS+(IC₅₀=0.131 mg/mL)自由基清除能力及还原能力(62.17 mg V_C/g)较其他品种核桃叶强。‘西林3号’核桃不同部位抗氧化活性测定显示,DPPH和ABTS+自由基清除力及FRAP还原力顺序从强到弱为:内种皮 > 叶 > 花粉 > 带皮种仁 > 去皮种仁。利用LC-MS从‘西林3号’内种皮及其核桃叶、KT-J02核桃叶、山核桃叶等4个供试样品的60%丙酮提取物中共鉴定出17种抗氧化活性成分,其中酚类9种,黄酮类8种,槲皮素和汉黄芩素为4种供试样品共有成分。山核桃叶中鉴定出13种成分,其中4种仅存在与山核桃中,即没食子酸、3-咖啡酰奎宁酸、表儿茶素没食子酸酯和对香豆酸;‘西林3号’和KT-J02核桃叶分别有1种成分仅存在于其中,为没食子酸-4-O-β-D-吡喃葡萄糖和儿茶素。内种皮中鉴定出6种成分,鞣花酸仅存在于内种皮中。

Antioxidant Activity and Compounds Identification of Kernels,Leaves and Pollen of Walnut(Juglandaceae)

In order to comprehensively develop walnut biological resources,the antioxidant activities of different walnut kernels,leaves and pollen extracted by 7 kinds of solvents were studied,and the antioxidant compounds of them were analyzed. Antioxidant activities were determined by DPPH and ABTS+ free radical scavenging abilities and FRAP reducing ability. The total phenol and total flavonoids were determined. The antioxidant compounds of the samples were detected by high resolution mass spectrometer. The results showed that the extracts obtained by 60% acetone as solvent had higher antioxidant activity in 7 solvents. DPPH(IC₅₀=0.156 mg/mL)and ABTS+(IC₅₀=0.131 mg/mL)radical scavenging power and reducing power(62.17 mg V_C/g)in pecan leaves were stronger than those of other leaves. Determination of antioxidant activity in different parts of ‘Xilin 3’ walnut showed that the order of DPPH and ABTS+ free radical scavenging power and FRAP reducing power from strong to weak was:Pellicle > leaves > pollen > kernel > peeling kernel. A total of 17 antioxidant active compounds were identified from 60% acetone extracts of ‘Xilin 3’ pellicle and walnut leaves,KT-J02 walnut leaves,pecan leaves by LC-MS,including 9 phenols and 8 flavonoids. Quercetin and wogonin were common compounds in 4 test samples. For walnut leaves,13 compounds were identified in the pecan leaves,4 kinds of unique compounds,namely gallic acid,3-caffeoyl quinic acid,epicatechin gallate and p-coumaric acid. There was one compounds for each in ‘Xilin 3’ and KT-J02 leaves,gallic acid-4-O-β-D-glucopyranose and catechin,respectively. Six components were identified in pellicle,and one unique compound was ellagic acid.