Pina Fernando
REQUIMTE, Departamento de Quı́mica, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal.
J Agric Food Chem. 2014 Jul 23;62(29):6885-97. doi: 10.1021/jf404869m. Epub 2014 Jan 15.
Independently of the natural or synthetic origin, flavylium derivatives follow the same network of chemical reactions. Actually, the flavylium cation is stable only at low pH values. Increasing the pH gives rise to the formation of several species: quinoidal bases, hemiketal, cis- and trans-chalcones, and their deprotonated forms. A deep knowledge of the thermodynamics and kinetics of these species is an essential tool to practical applications of these compounds, in particular, in the domain of food chemistry. In this work the network of chemical reactions involving flavylium derivatives is presented, and the respective thermodynamics and kinetics are discussed in detail, including the mathematical expressions and a step-by-step procedure to calculate all of the rate and equilibrium constants of the system. Examples of systems possessing a high or low cis-trans isomerization barrier are shown. Recent practical applications of anthocyanins and related compounds illustrate the potentialities of the flavylium-based family of compounds.
无论黄酮类衍生物是天然来源还是合成来源，它们都遵循相同的化学反应网络。实际上，黄酮阳离子仅在低pH值下稳定。提高pH值会导致形成多种物种：醌型碱、半缩酮、顺式和反式查耳酮及其去质子化形式。深入了解这些物种的热力学和动力学是这些化合物实际应用的重要工具，特别是在食品化学领域。在这项工作中，展示了涉及黄酮类衍生物的化学反应网络，并详细讨论了各自的热力学和动力学，包括数学表达式以及计算系统所有速率和平衡常数的逐步程序。给出了具有高或低顺反异构化势垒的系统示例。花青素及相关化合物的近期实际应用说明了基于黄酮类的化合物家族的潜力。
