Theoretical investigation into the cooperativity effect of 1,4-dimethoxy-d-glucosamine complex with Na+ and H2O

• Published in: Journal of molecular modeling Vol. 26; no. 8; p. 203
• Main Authors: Zhao, Jin-an, Ren, Fu-de
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2020; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemical bonds; Chemistry; Chemistry and Materials Science; Chitin; Chitosan; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Deduction; Hydration; Molecular Medicine; Original Paper; Theoretical and Computational Chemistry; glucosamine; Cooperativity effect between H-bonding and cation-molecule interactions; ωB97X-D; Hydration; 1,4-Dimethoxy
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-020-04461-x

In order to explore the essence of the hydration process of chitin or chitosan in the presence of cation, the cooperativity effects between the H-bonding and Na + ···molecule interactions in the 1,4-dimethoxy- d -glucosamine (DMGA) complexes with H 2 O and Na + were investigated at the B3LYP/6-311++G(d,p), M06-2X/6-311++G(2df,2p), and ωB97X-D/6-311++G(2df,2p) levels. The result shows that the complexes in which Na + or H 2 O is bonded simultaneously to the –NH and –OH groups connected to the C3 atom of DMGA are the most stable. The cooperativity and anti-cooperativity effects occur in DMGA···H 2 O···DMGA and DMGA···Na + ···H 2 O, while only the cooperativities are confirmed in DMGA···Na + ···DMGA. The cooperativity occurs in the DMGA···Na + ···H 2 O complexes without the hydration, while the anti-cooperativity occurs in those with the hydration. Furthermore, the cooperativity and anti-cooperativity in DMGA···Na + ···H 2 O are far stronger than those in DMGA···Na + ···DMGA or DMGA···H 2 O···DMGA. Therefore, a deduction is given that the cooperativity and anti-cooperativity effects play an important role in the hydration of chitin or chitosan in the presence of Na + . When only Na + is linked with –OH and –NH groups of chitosan or chitin, due to the cooperativity effect, the hydration does not occur. When both Na + and H 2 O are linked with –OH and –NH groups, the anti-cooperativities are dominant in controlling of the aggregation process of Na + , H 2 O, chitosan, and chitin, leading to the possible hydration. Atoms in molecules (AIM) analysis confirms the cooperativity and anti-cooperativity effects. Graphical abstract