Clarifying the Identity of the Main Ellagitannin in the Fruit of the Strawberry, Fragaria vesca and Fragaria ananassa Duch.

Although the composition of strawberry fruit has been extensively studied, especially for the most abundant phenolic compounds, agrimoniin has never been univocally identified as one of the most abundant phenolic compounds in the fruit. In this study agrimoniin was isolated in the fruit of Fragaria vesca and its structure characterized. Furthermore, its presence was definitively established to be the main ellagitannin in both F. vesca and Fragaria ananassa D. fruit. The presence of sanguiin H-6 and lambertianin C as minor compounds was confirmed in both F. vesca and F. ananassa D. samples. For the first time here is reported the full NMR assignments for agrimoniin. These data should represent a point of reference for NMR analysis of this and other structurally related ellagitannins. Finally, the establishment of an HPLC protocol for separation provided information making it possible to avoid confusion with sanguiin H-6, the main ellagitannin in Rubus species, which is also present in strawberries but at a much lower concentration.尽管草莓果实的组成已被广泛研究，尤其是针对其中丰度最高的酚类化合物而言，但仙鹤草素（agrimoniin）此前从未被明确认定为该果实中主要酚类成分之一。本研究从森林草莓（Fragaria vesca）的果实中分离得到仙鹤草素，并完成其结构表征。此外，本研究明确证实，仙鹤草素是森林草莓与栽培草莓（Fragaria ananassa D.）果实中的主要鞣花单宁（ellagitannin）成分。研究同时确认，两类样品中均存在次要成分血根鞣花素H-6（sanguiin H-6）与兰伯特鞣花素C（lambertianin C）。本研究首次报道了仙鹤草素的完整核磁共振波谱（NMR）归属数据，该数据可为仙鹤草素及其它结构相关鞣花单宁的核磁共振波谱分析提供参考基准。最后，本研究建立的高效液相色谱（HPLC）分离方案，可有效规避与血根鞣花素H-6的混淆——该物质是悬钩子属植物的主要鞣花单宁成分，虽也存在于草莓果实中，但浓度远低于仙鹤草素。