Isolation and identification of 5-carboxy-pyranoanthocyanins in beverages from cherry (Prunus cerasus L.)

Novel pyranoanthocyanins were identified by HPLC-ESI-MSn in fermented and unfermented fruit juices from cherry (Prunus cerasus L.). The two major compounds, namely 5-carboxy-pyranocyanidin 3-O-(2(G)-glucosylrutinoside) and 5-carboxy-pyranocyanidin 3-O-rutinoside were isolated by a combination of high-speed countercurrent chromatography with semi-preparative HPLC. Their structures were fully elucidated by means of NMR spectroscopy and mass spectrometry. As minor compounds 5-carboxy-pyranocyanidin 3-glucoside, 5-carboxy-pyranopeonidin-3-glucoside, and 5-carboxy-pyranopeonidin 3-rutinoside could be identified. These compounds are formed during storage of the juice through the reaction of pyruvic acid with the respective genuine anthocyanins. (c) 2007 Elsevier Ltd. All rights reserved.