Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
J Agric Food Chem. 2012 Feb 8;60(5):1167-74. doi: 10.1021/jf203431g. Epub 2012 Jan 27.
Ellagitannins from red raspberries (Rubus idaeus) and cloudberries (Rubus chamaemorus) were isolated by using column chromatography and preparative HPLC. The berry phenolic isolates consisted of 80% (cloudberry) and of 60% (raspberry) of ellagitannins, with raspberries also containing anthocyanins. The main ellagitannins of both raspberries and cloudberries were identified by ESI-MS to consist of the dimeric sanguiin H-6 and the trimeric lambertianin C. Monomeric ellagitannins such as casuarictin in raspberries and pedunculagin in cloudberries were also found. The antioxidant activity of the berry phenolic isolate, ellagitannin isolate (mixture), ellagitannin main fraction (dimer and trimer), and ellagic acid was studied in bulk and emulsified methyl linoleate, in human low-density lipoprotein in vitro, and the radical scavenging activity was studied in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. Cloudberry and red raspberry ellagitannins were highly effective as radical scavengers. Berry ellagitannins also showed significant antioxidant activity toward oxidation of both human LDL and methyl linoleate emulsions. However, only weak or moderate antioxidant activity was exhibited by ellagitannins toward oxidation of bulk oil. Thus, ellagitannins contribute significantly to the antioxidant capacity of cloudberries and red raspberries in lipoprotein and lipid emulsion environments, the latter being more relevant for food applications.
从红树莓（Rubus idaeus）和云莓（Rubus chamaemorus）中分离出鞣花单宁，使用柱层析和制备高效液相色谱法。浆果酚类提取物由 80%（云莓）和 60%（树莓）的鞣花单宁组成，树莓还含有花青素。两种树莓和云莓的主要鞣花单宁都通过 ESI-MS 鉴定为二聚体 sanguiin H-6 和三聚体 lambertianin C。还发现了树莓中的单体鞣花单宁如 casuarictin 和云莓中的 pedunculagin。研究了浆果酚类提取物、鞣花单宁提取物（混合物）、鞣花单宁主要部分（二聚体和三聚体）和鞣花酸在块状和乳化甲基亚油酸、人低密度脂蛋白体外的抗氧化活性，以及在 2,2-二苯基-1-苦基肼（DPPH）试验中的自由基清除活性。云莓和红树莓鞣花单宁是非常有效的自由基清除剂。浆果鞣花单宁对人 LDL 和甲基亚油酸乳状液的氧化也表现出显著的抗氧化活性。然而，鞣花单宁对块状油的氧化仅表现出弱或中等的抗氧化活性。因此，鞣花单宁在脂蛋白和脂质乳液环境中对云莓和红树莓的抗氧化能力有重要贡献，后者更适用于食品应用。
