caa a22 4500 605512744 CHVBK 20210128100657.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00894-015-2591-7 doi (NATIONALLICENCE)springer-10.1007/s00894-015-2591-7 A computational study of intramolecular hydrogen bonds breaking/formation: impact on the structural flexibility of the ranitidine molecule [Elektronische Daten] [Mariana Kozlowska, Jakub Goclon, Pawel Rodziewicz] Ranitidine is a histamine H2-receptor antagonist that reduces gastric acid secretion. We studied the flexibility of the ranitidine molecule with the special focus on the network of diverse intramolecular hydrogen bonds: N-H ⋯O, N-H ⋯N, C-H ⋯O, C-H ⋯N and N-H ⋯S. We performed static density functional theory calculations of global and local minima and analyzed their stability at finite temperature in the Car-Parrinello molecular dynamics simulations. We observed intramolecular H-bonds breaking/formation crucial for the structural rearrangements leading to the folding process. The lifetimes of the closed structures of ranitidine were also estimated. The existence of hydrogen bonds and their strength were confirmed on the basis of topological parameters in the bond critical points utilizing Quantum Theory of Atoms in Molecules. Springer-Verlag Berlin Heidelberg, 2015 Ranitidine nationallicence Intramolecular hydrogen bonds nationallicence AIM analysis nationallicence Car-Parrinello molecular dynamics nationallicence Structural flexibility nationallicence Kozlowska Mariana Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399, Bialystok, Poland aut Goclon Jakub Interdisciplinary Center for Molecular Materials (ICMM), and Computer-Chemistry-Center (CCC), Friedrich-Alexander-University Erlangen-Nürnberg, Nägelsbachstr. 25, 91052, Erlangen, Germany aut Rodziewicz Pawel Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399, Bialystok, Poland aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/4(2015-04-01), 1-11 1610-2940 21:4<1 2015 21 894 https://doi.org/10.1007/s00894-015-2591-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2591-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kozlowska Mariana Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399, Bialystok, Poland aut NATIONALLICENCE 700 1- Goclon Jakub Interdisciplinary Center for Molecular Materials (ICMM), and Computer-Chemistry-Center (CCC), Friedrich-Alexander-University Erlangen-Nürnberg, Nägelsbachstr. 25, 91052, Erlangen, Germany aut NATIONALLICENCE 700 1- Rodziewicz Pawel Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399, Bialystok, Poland aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/4(2015-04-01), 1-11 1610-2940 21:4<1 2015 21 894