He Jingren, Santos-Buelga Celestino, Silva Artur M S, Mateus Nuno, de Freitas Victor
Centro de Investigaçâo em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
J Agric Food Chem. 2006 Dec 13;54(25):9598-603. doi: 10.1021/jf062325q.
Two newly formed yellow pigments that revealed unique spectral features were detected and isolated from an aged Port red wine by TSK Toyopearl HW-40(s) gel chromatography and characterized by UV-visible spectrophotometry, 1H NMR and 13C NMR, and mass spectrometry (LC-ESI/MS). The UV-vis spectra of these pigments showed maximum absorption at 478 nm that is significantly hypsochromically shifted from those of original grape anthocyanins and other pyranoanthocyanins, exhibiting a more yellow hue in acidic solution. The structures of these pigments correspond to methyl-linked pyranomalvidin 3-glucoside and its respective coumaroyl glucoside derivative. They were shown to arise from the reaction between acetoacetic acid and genuine grape anthocyanins. Isolation and NMR identification using 1D and 2D NMR techniques are reported for the first time for this new family of anthocyanin-derived yellow pigments occurring in red wines.
通过TSK Toyopearl HW - 40(s)凝胶色谱法从一瓶陈年波特红酒中检测并分离出两种呈现独特光谱特征的新形成的黄色色素，并用紫外可见分光光度法、¹H NMR和¹³C NMR以及质谱法（LC - ESI/MS）对其进行了表征。这些色素的紫外可见光谱在478 nm处显示出最大吸收，与原始葡萄花青素和其他吡喃花青素相比有明显的紫移，在酸性溶液中呈现出更黄的色调。这些色素的结构对应于甲基连接的吡喃锦葵色素3 - 葡萄糖苷及其各自的香豆酰葡萄糖苷衍生物。结果表明它们是由乙酰乙酸与真正的葡萄花青素之间的反应产生的。首次报道了使用一维和二维NMR技术对红葡萄酒中出现的这种新的花青素衍生黄色色素家族进行分离和NMR鉴定。
