Взаємодія N-ацетилнейрамінової кислоти з поверхнею кремнезему у водному розчині за участі вуглеводів

• Date: 2020
• Main Authors: Ушакова, Л. М., Дем’яненко, Є. M., Терець, М. І., Лобанов, В. В., Картель, М. Т.
• Format: Article
• Language: English
• Published: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2020
• Subjects: поверхня кремнезему; адсорбція N-ацетилнейрамінової кислоти; глюкоза; сахароза; супермолекулярне наближення; метод функціонала густини
• Online Access: https://surfacezbir.com.ua/index.php/surface/article/view/700
• Journal Title: Surface

The aim of the work is to study interaction of N-acetylneuraminic acid (NANA) with the surface of ultrafine silica (UFS) with the participation of glucose and sucrose in aqueous solution at the supramolecular level by density functional theory method (exchange-correlation functional B3LYP, basis set of 6-31G (d, p). The adsorption of N-acetylneuraminic acid, as well as individual carbohydrates (glucose and sucrose) on the hydrated surface of UFS in aqueous solution, was considered as a process of replacement of water molecules on the surface of silica by adsorbate molecules. This work considers two schemes of carbohydrate molecule influence on adsorption of N-acetylneuraminic acid. According to the first scheme the interaction of the NANA molecule occurs with the silica-monosaccharide complex, according to the second scheme, the silica cluster interacts with the NANA-monosaccharide complex, where silica binds to the complex through the carbohydrate molecule. The analysis of the calculated geometric and energy characteristics show that adsorption on the surface of silica, with hydration taken into account, is thermodynamically probable for the sucrose. The glucose molecule has a positive value (+9.8 and +2.7 kJ / mol) is an unfavorable process in terms of thermodynamics regardless of the hydrating water cluster size. The N-acetylneuraminic acid molecule has a value of -1.3 kJ / mol for the reaction with five water molecules and +0.9 kJ / mol with eight water molecules. It was found that the presence of sucrose on the silica surface in the aqueous solution weakens the hydration energy (i.e. it is easier to replace the cluster of water with the N-acetylneuraminic acid molecule from the surface of the modified adsorbent), which in turn promotes NANA adsorption on the silica surface. Therefore, scheme 1 is thermodynamically more likely than scheme 2. This indicates that there is a mutual influence of substances in a mixture of NANA with carbohydrates on the interaction with silica in comparison with the interaction of substances with silica alone.