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Eggers DK, Le JM, Nham NT, Pham DN, Castellano BM. Dual Effect of Secondary Solutes on Binding Equilibria: Contributions from Solute-Reactant Interactions and Solute-Water Interactions. ACS OMEGA 2024; 9:3017-3027. [PMID: 38250344 PMCID: PMC10795149 DOI: 10.1021/acsomega.3c09329] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/08/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024]
Abstract
This study examines the role of water in binding equilibria with a special focus on secondary solutes (cosolutes) that influence the equilibrium but are not constituents of the final product. Using a thermodynamic framework that includes an explicit term for the release of water molecules upon binding, this investigation reveals how solutes may alter equilibria by changing the activity of the reactants, reflected in ΔG°(obs), and by changing the chemical potential of the solvent, reflected in ΔGS. The framework is applied to four experimental binding systems that differ in the degree of electrostatic contributions. The model systems include the chelation of Ca2+ by EDTA and three host-guest reactions; the pairings of p-sulfonatocalix[4]arene with tetramethylammonium ion, cucurbit[7]uril with N-acetyl-phenylalanine-amide, and β-cyclodextrin with adamantane carboxylate are tested. Each reaction pair is examined by isothermal titration calorimetry at 25 °C in the presence of a common osmolyte, sucrose, and a common chaotrope, urea. Molar solutions of trehalose and phosphate were also tested with selected models. In general, cosolutes that enhance binding tend to reduce the solvation free energy penalty and cosolutes that weaken binding tend to increase the solvation free energy penalty. Notably, the nonpolar-nonpolar interaction between adamantane carboxylate and β-cyclodextrin is characterized by a ΔGS value near zero. The results with β-cyclodextrin, in particular, prompt further discussions of the hydrophobic effect and the biocompatible properties of trehalose. Other investigators are encouraged to test and refine the approach taken here to further our understanding of solvent effects on molecular recognition.
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Affiliation(s)
- Daryl K. Eggers
- Department of Chemistry, San José State University, San José, California 95192-0101, United
States
| | | | | | - Duc N. Pham
- Department of Chemistry, San José State University, San José, California 95192-0101, United
States
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Miao W, Yue M, Qiu C, Li X, Sang S, McClements DJ, Chen L, Long J, Jiao A, Wang J, Jin Z. Interactions between plant-derived antioxidants and cyclodextrins and their application for improving separation, detection, and food quality issues. Crit Rev Food Sci Nutr 2023; 64:7085-7100. [PMID: 36798974 DOI: 10.1080/10408398.2023.2180479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Plant-derived antioxidants (PD-AOs) are important for food preservation, as well as for human health and nutrition. However, the poor chemical stability and water solubility of many PD-AOs currently limit their application as functional ingredients in foods and pharmaceuticals. Moreover, it is often difficult to isolate and detect specific antioxidants in multi-component systems, which again limits their potential in the food and medical industries. In this review, we highlight recent advances in the use of cyclodextrins (CDs) to overcome these limitations by forming simple, modified and competitive host-guest interactions with PD-AO. The host-guest properties of CDs can be used to enhance the separation efficiency of PD-AOs, as well as to improve their dispersion and stability in food systems. Moreover, the competitive complexation properties of CDs with target molecules can be used to selectively isolate PD-AOs from multi-component systems and develop detection technologies for PD-AOs. Overall, CD-antioxidant interactions have great potential for addressing isolation, detection, and food quality issues.
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Affiliation(s)
- Wenbo Miao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Mengyun Yue
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Chao Qiu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Xiaojing Li
- College of Light Industry and Food Engineering, Nanjing Forestry University, Jiangsu, China
| | - Shangyuan Sang
- Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | | | - Long Chen
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Jie Long
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Aiquan Jiao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Jinpeng Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
| | - Zhengyu Jin
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, China
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Samuelsen L, Holm R, Schönbeck C. Exploring the interactions between buffers and cyclodextrin complexes—formation of regular inclusion or atypical non-inclusion complexes. J INCL PHENOM MACRO 2021. [DOI: 10.1007/s10847-021-01111-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Samuelsen L, Holm R, Schönbeck C. Simultaneous determination of cyclodextrin stability constants as a function of pH and temperature – A tool for drug formulation and process design. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Samuelsen L, Holm R, Schönbeck C. Specific Buffers Affect the Stability of a Charged Cyclodextrin Complex Via Competitive Binding and Ionic Strength. J Pharm Sci 2021; 110:2661-2668. [PMID: 33607189 DOI: 10.1016/j.xphs.2021.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/27/2021] [Accepted: 02/08/2021] [Indexed: 11/25/2022]
Abstract
The effect of 11 buffers as well as the effect of ionic strength were investigated on the binding between the bile salt taurochenodeoxycholate and the ionic sulfobutylether-β-cyclodextrin. The investigations showed that both ionic strength and competitive binding affected the stability constant. The stability constant for the sulfobutylether-β-cyclodextrin complex increased from 34,400 M-1 to 114,000 M-1 as the ionic strength of the solution increased to 0.15 M. Keeping the ionic strength constant, the stability constant for the complex depended on the buffer in the solution, with citric and succinic acid reducing the stability constant. The reduction in the stability constant by buffers was related to a competitive mechanism. The results showed that, when accounting for the variation in ionic strength between the buffers, three groupings of buffers existed. All carboxylic acid buffers decreased the stability constant of the sulfobutylether-β-cyclodextrin complex, relative to the effect observed by altering the ionic strength, whereas the other buffers only affected the stability constant in terms of the changes in ionic strength. Both buffer species and ionic strength impacted the stability of ionic cyclodextrin complexes, hence, it is important to be aware of these effects when working with, comparing and reporting stability constants.
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Affiliation(s)
- Lisa Samuelsen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - René Holm
- Department of Science and Environment, Roskilde University, Roskilde, Denmark; Drug Product Development, Janssen Research and Development, Johnson & Johnson, Beerse, Belgium.
| | - Christian Schönbeck
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
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