Department of Viticulture and Enology, University of California, Davis, CA, 95616, USA; Agricultural and Environmental Chemistry Graduate Group, University of California, Davis, CA, 95616, USA.
Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Straße 20, 3430, Tulln, Austria.
Anal Chim Acta. 2019 Apr 25;1054:74-83. doi: 10.1016/j.aca.2018.12.019. Epub 2018 Dec 15.
Quinones are key reactive electrophilic intermediates that are formed in abundance during wine oxidation and have a significant impact on wine character, altering color and flavor. They readily react with nucleophiles, such as SO and glutathione. Some nucleophiles have been reported to react with quinones in model wines, but many of the corresponding products have not been confirmed in real wines. Here, a stable isotope labeling approach employing C labeled ortho-quinone was evaluated in combination with an exact-mass list of putative products. The measurements were taken using high performance liquid chromatography coupled to time-of-flight mass spectrometry. Fourteen compounds were detected based on a match in the table plus an M+6 mass isotope pattern derived from the labeled quinone mixture. The presence of the mass label also establishes reaction pathways for the formation of these compounds, and suggests how wine catechols could react during wine oxidation, demonstrating the insight provided by this analytical technique.
醌类物质是反应性亲电中间体的关键，在葡萄酒氧化过程中大量形成，对葡萄酒的特性有重大影响，改变颜色和风味。它们很容易与亲核试剂如 SO 和谷胱甘肽反应。已经有报道称，一些亲核试剂在模型葡萄酒中与醌类物质反应，但在实际葡萄酒中并没有确认许多相应的产物。在这里，采用 C 标记邻醌的稳定同位素标记方法与可能产物的精确质量列表相结合进行了评估。使用高效液相色谱与飞行时间质谱联用进行了测量。根据表中的匹配以及标记醌混合物衍生的 M+6 质量同位素模式，检测到了 14 种化合物。质量标签的存在还为这些化合物的形成建立了反应途径，并表明葡萄酒儿茶酚类物质在葡萄酒氧化过程中如何反应，展示了这种分析技术提供的见解。
