Abstract:
The encapsulation of sodium sulfobutylether-β-cyclodextrin (SBE-β-CD) is influenced not only by the degree of substitution (DS) but also by the presence of strong-bonded water (SBW). Guests compete with SBW for positions within the cavity of SBE-β-CD. However, the correlation between DS and SBW was not clear. This study revealed a positive correlation between DS and SBW utilizing Karl Fischer titration. The mechanism may be attributed to molecular polarizability. To explore the impact of SBW inside SBE-β-CD with different DS on encapsulation, density functional theory was employed. Throughout the release process, an increase in enthalpy is unfavorable, while an increase in entropy favors spontaneous reaction occurrence. For SBE-β-CD (DS = 2, 3), enthalpy increase is the primary factor, leading to the retention of SBW within the cavities and consequently hindering guest entry. In contrast, for SBE-β-CD (DS = 4, 7), the situation differs. For SBE10-β-CD, the influence of SBW is minimal. This study aims to elucidate the relationship between DS and SBW, as well as the effect of SBW inside SBE-β-CD with different DS on encapsulation. It is crucial for a comprehensive understanding of the factors affecting the encapsulation of SBE-β-CD, thereby promoting quality control and functional development of SBE-β-CD.
摘要:
磺丁基醚-β-环糊精钠(SBE-β-CD)的包封不仅受取代度(DS)的影响,而且受强键合水(SBW)的存在的影响。客人与SBW竞争SBE-β-CD空腔内的位置。然而,DS和SBW之间的相关性不明确。这项研究揭示了使用卡尔费休滴定法的DS和SBW之间的正相关。该机制可归因于分子极化性。为探讨SBE-β-CD内不同DS的SBW对包封的影响,采用密度泛函理论。在整个发布过程中,焓的增加是不利的,而熵的增加有利于自发反应的发生。对于SBE-β-CD(DS=2,3),焓增加是主要因素,导致SBW保留在空腔内,从而阻碍客人进入。相比之下,对于SBE-β-CD(DS=4,7),情况不同。对于SBE10-β-CD,SBW的影响是最小的。本研究旨在阐明DS和SBW之间的关系,以及不同DS的SBE-β-CD内SBW对包封的影响。对于全面了解影响SBE-β-CD包封的因素至关重要,从而促进SBE-β-CD的质量控制和功能开发。