Sun Baoshan, Santos Cláudia P Reis, Leandro Maria C, De Freitas Vítor, Spranger Maria I
Estação Vitivinícola Nacional - Instituto Nacional de Investigação Agrária e das Pescas, Quinta da Almoinha, 2565-191 Dois Portos, Portugal.
Rapid Commun Mass Spectrom. 2007;21(14):2227-36. doi: 10.1002/rcm.3082.
Monomer and polymer flavan-3-ols and anthocyanins are the two major groups of phenolic compounds in red wine and one of the most important reactions during red wine ageing is the condensation reaction, either direct or indirect, between these two classes of compounds. In this work, the reaction of (+)-catechin, (-)-epicatechin and dimer procyanidin B2 with malvidin 3-glucoside, in the presence of acetaldehyde, was carried out in wine model solutions at pH 1.7 and 3.2. Identification of the reaction products was carried out by high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) and MS(n) analysis. Various reaction products were detected. The structures of three condensation products - malvidin-3-glucoside-ethyl-(epi)catechin-1''-hydroxyethyl, malvidin-3-glucoside-ethyl-dimer-vinyl and malvidin-3-glucoside-ethyl-dimer-1''-hydroxyethyl - were identified in a model solution for the first time. Moreover, in the reaction solution containing dimer B2 at pH 3.2, monomer epicatechin, trimer and tetramer procyanidins were also detected indicating that, under these conditions, dimer procyanidins can either be hydrolyzed to monomers or polymerized to higher oligomer or polymers.
单体和聚合物黄烷-3-醇以及花色苷是红葡萄酒中两类主要的酚类化合物，红葡萄酒陈酿过程中最重要的反应之一是这两类化合物之间直接或间接的缩合反应。在这项研究中，在乙醛存在的情况下，于pH值为1.7和3.2的葡萄酒模拟溶液中，使（+）-儿茶素、（-）-表儿茶素和二聚体原花青素B2与矢车菊素3-葡萄糖苷发生反应。通过高效液相色谱/电喷雾电离质谱（HPLC/ESI-MS）和MS（n）分析对反应产物进行鉴定。检测到了多种反应产物。首次在模拟溶液中鉴定出三种缩合产物的结构，即矢车菊素-3-葡萄糖苷-乙基-（表）儿茶素-1''-羟乙基、矢车菊素-3-葡萄糖苷-乙基-二聚体-乙烯基和矢车菊素-3-葡萄糖苷-乙基-二聚体-1''-羟乙基。此外，在pH值为3.2且含有二聚体B2的反应溶液中，还检测到了单体表儿茶素、三聚体和四聚体原花青素，这表明在这些条件下，二聚体原花青素既可以水解为单体，也可以聚合成更高的低聚物或聚合物。
