Molecules, Vol. 28, Pages 7497: Density Functional Theory and Density Functional Tight Binding Studies of Thiamine Hydrochloride Hydrates

Molecules, Vol. 28, Pages 7497: Density Functional Theory and Density Functional Tight Binding Studies of Thiamine Hydrochloride Hydrates Molecules doi: 10.3390/molecules28227497 Authors: Ewa Napiórkowska Łukasz Szeleszczuk Katarzyna Milcarz Dariusz Maciej Pisklak Thiamine hydrochloride (THCL), also known as vitamin B1, is an active pharmaceutical ingredient (API), present on the list of essential medicines developed by the WHO, which proves its importance for public health. THCL is highly hygroscopic and can occur in the form of hydrates with varying degrees of hydration, depending on the air humidity. Although experimental characterization of the THCL hydrates has been described in the literature, the questions raised in previously published works suggest that additional research and in-depth analysis of THCL dehydration behavior are still needed. Therefore, the main aim of this study was to characterize, by means of quantum chemical calculations, the behavior of thiamine hydrates and explain the previously obtained results, including changes in the NMR spectra, at the molecular level. To achieve this goal, a series of DFT (CASTEP) and DFTB (DFTB+) calculations under periodic boundary conditions have been performed, including molecular dynamics simulations and GIPAW NMR calculations. The obtained results explain the differences in the relative stability of the studied forms and changes in the spectra observed for the samples of various degrees of hydration. ...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research