Sunflower seed extract, an antioxidant agent registered on the List of Existing Food Additives in Japan, was evaluated using HPLC, and three common constituents were detected. These peaks were identified as monocaffeoylquinic acids (3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, and 5-O-caffeoylquinic acid [chlorogenic acid]). Upon scrutinizing other components, dicaffeoylquinic acids (isochlorogenic acids; 3,4-di-O-caffeoylquinic, 3,5-di-O-caffeoylquinic, and 4,5-di-O-caffeoylquinic acids) were also identified. Structures of two newly isolated compounds were determined to be 3-O-(3S-2-oxo-3-hydroxy-indole-3-acetyl)-5-O-caffeoylquinic and 4-O-(3S-2-oxo-3-hydroxy-indole-3-acetyl)-5-O-caffeoylquinic acids. To identify the components that contribute to the antioxidant activity of sunflower seed extract, we fractionated the food additive sample solution and examined the active fractions for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Monocaffeoylquinic and dicaffeoylquinic acids showed high DPPH activity, including their contribution to the antioxidant activity of this food additive. DPPH radical scavenging activity of the new compounds showed almost the same value as that of the positive control, Trolox. Therefore, the contribution of these compounds was also considered.

使用 HPLC 对在日本现有食品添加剂清单中注册的抗氧化剂葵花籽提取物进行评估，并检测到三种常见成分。这些峰被鉴定为单咖啡酰奎尼酸（3- O-咖啡酰奎尼酸、4- O-咖啡酰奎尼酸和5- O-咖啡酰奎尼酸[绿原酸]）。在仔细检查其他成分后，还鉴定出了二咖啡酰奎尼酸（异绿原酸；3,4-二-O-咖啡酰奎尼酸、3,5-二-O-咖啡酰奎尼酸和4,5-二-O-咖啡酰奎尼酸）。两个新分离的化合物的结构确定为3- O- (3S - 2-氧代-3-羟基-吲哚-3-乙酰基)-5- O-咖啡酰奎宁和4- O- (3S - 2-氧代) -3-羟基-吲哚-3-乙酰基)-5- O-咖啡酰奎尼酸。为了确定有助于葵花籽提取物抗氧化活性的成分，我们对食品添加剂样品溶液进行了分馏，并检查了活性馏分的 2,2-二苯基-1-三硝基苯肼 (DPPH) 自由基清除活性。单咖啡酰奎尼酸和二咖啡酰奎宁酸表现出高 DPPH 活性，包括它们对该食品添加剂的抗氧化活性的贡献。新化合物的 DPPH 自由基清除活性几乎与阳性对照 Trolox 相同。因此，也考虑了这些化合物的贡献。