Semipreparative Chromatographic Procedure for the Isolation of Dimeric and Trimeric Proanthocyanidins from Barley

作者：Ian McMurrough, David Madigan, Malcolm R. Smyth · 发表于：Journal of Agricultural and Food Chemistry · 年份：1996 · DOI：10.1021/jf960139m · 被引用次数：86 · 研究领域：Fermentation and Sensory Analysis、Biochemical Analysis and Sensing Techniques、Phytochemicals and Antioxidant Activities

A semipreparative chromatographic method for the isolation of small amounts (10−20 μg) of dimeric and trimeric proanthocyanidins from barley is described. Concentrated extracts of barley were injected onto a high-performance gel filtration column (Superdex 75 HR), and were eluted with methanol. This procedure resolved the dimeric proanthocyanidins (prodelphinidin B3 and procyanidin B3), as well as the trimeric procyanidin C2 and three other trimeric prodelphinidins. The separated flavanoid peaks were collected and their contents were estimated by UV spectrophotometry, reaction with p -dimethylaminocinnamadehyde, and reversed phase HPLC with electrochemical detection. This method produced proanthocyanidins in sufficient amounts to calibrate a system for direct injection chromatographic analysis of beers and barley extracts. The method described may be optimized for the isolation of dimeric proanthocyanidins only, in which case the preparation can take as little as 3 h; alternatively, by extending the chromatographic separation to 9 h, the four major trimeric proanthocyanidins of barley can be recovered also in a chromatographically pure state. Keywords: Analysis; barley; beer; calibration standard; high-performance liquid chromatography; proanthocyanidin