Faculty of Pharmacy, University of Ljubljana, Aškerčeva cesta 7, Ljubljana SI-1000, Slovenia.
Food Chem. 2014 Jan 15;143:432-9. doi: 10.1016/j.foodchem.2013.07.118. Epub 2013 Aug 9.
Buckwheat products are commonly used in health foods and food supplements. However, public awareness regarding the presence of photodynamic naphthodianthrones fagopyrins that can cause photosensitization is low. At least two additional compounds with structures similar to that of fagopyrin are known to exist; however, the structures of these compounds have never been determined. In this work, we improved the extraction procedure and the chromatographic analysis of fagopyrins by developing a simple, sensitive and high-resolution high performance liquid chromatography (HPLC) analytical method using fluorescence detection. We observed at least six fagopyrin derivatives, which were isolated and characterized via UV-Vis absorption, NMR spectroscopy and mass spectrometry. We determined the structures of two new derivatives (fagopyrin A and fagopyrin E) and proved the existence of protofagopyrins that can transform into fagopyrins upon light exposure. Our methods complement the existing knowledge regarding fagopyrins and will allow for their further analysis, isolation and investigation of their biological activity.
荞麦制品通常被用作保健食品和食品补充剂。然而，公众对可能引起光敏作用的光动力萘并二蒽酮荞麦酚的存在的认识很低。至少还有两种结构与荞麦酚类似的额外化合物，但这些化合物的结构从未被确定过。在这项工作中，我们通过开发一种简单、灵敏和高分辨率的高效液相色谱（HPLC）荧光检测分析方法，改进了荞麦酚的提取程序和色谱分析。我们观察到至少六种荞麦酚衍生物，通过紫外可见吸收、核磁共振波谱和质谱对其进行了分离和表征。我们确定了两种新衍生物（荞麦酚 A 和荞麦酚 E）的结构，并证明了原荞麦酚的存在，原荞麦酚在光照下可以转化为荞麦酚。我们的方法补充了现有的荞麦酚知识，并将允许对其进一步分析、分离和研究其生物活性。
