Phenolic acids are phytochemicals commonly existing in plants that are also beneficial to the human body after consumption. As additives in the food industry, phenolic acids typically need stabilization by encapsulation. We have been studying cyclodextrins as potential encapsulating agents, elucidating the structure and energetics of the complexes they form with phenolic acids. To highlight the role of the solvent in these interactions and to investigate the possible component ratios available to these complexes, we first carried out gas-phase studies monitored through mass spectrometry that allowed us to work in solvent-free conditions. In addition to detecting the products of these complexation equilibria qualitatively, we were also able to find conditions to quantitative determine the relative binding affinities associated with these processes. As well as on the unusual complex stoichiometry observed in the gas phase for a series of phenolic acids with α-CD, β-CD, and γ-CD. We propose an explanation of these uncommon stoichiometries through solvation effects involving the cyclodextrin host as the solvating species. We also report on the observed trends in the measured relative affinities of these interactions.

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环糊精中酚酸的气相无溶剂络合：质谱研究

酚酸是植物中普遍存在的植物化学物质，食用后对人体也有益。作为食品工业中的添加剂，酚酸通常需要通过封装来稳定。我们一直在研究环糊精作为潜在的封装剂，阐明它们与酚酸形成的复合物的结构和能量学。为了强调溶剂在这些相互作用中的作用并研究这些复合物可能的成分比例，我们首先进行了通过质谱监测的气相研究，这使我们能够在无溶剂条件下工作。除了定性检测这些络合平衡的产物之外，我们还能够找到定量确定与这些过程相关的相对结合亲和力的条件。以及在气相中观察到的一系列酚酸与 α-CD、β-CD 和 γ-CD 的不寻常的复杂化学计量。我们提出通过涉及环糊精主体作为溶剂化物质的溶剂化效应来解释这些不常见的化学计量。我们还报告了这些相互作用的测量相对亲和力的观察趋势。