Aqueous solvation study of melatonin using ab initio molecular dynamics

Autor: Hamilton B. Napolitano, Lóide O. Sallum, Lilian T. F. M. Camargo, Allane C. C. Rodrigues, Yago Francisco Lopes, Ademir J. Camargo
Rok vydání: 2021
Předmět:
Zdroj: Journal of Molecular Liquids. 343:117451
ISSN: 0167-7322
DOI: 10.1016/j.molliq.2021.117451
Popis: Melatonin is an essential human hormone produced mainly by the pineal gland from the amino acid tryptophan; it has several types of bioactivity, such as regulation of circadian rhythm, antioxidant, and DNA protection. Despite the importance of melatonin in the human body, studies on the interaction of melatonin with water molecules, considered explicitly, are quite limited in the literature. Thus, the present work reports a study on the effects of aqueous solvation on the geometric and electronic parameters of melatonin using Car-Parrinello Molecular Dynamics (CPMD). The CPMD results show that the aqueous solvation of melatonin affects mainly C14-O2 (2.176%), N17-C14 (2.169%), and N16-H21 (1.079%) bond lengths as well as O1-C3-C4 (4.37%) and O1-C3-C8 (4.241%) bond angles. These effects are attributed mainly to the H-bond formation between O1, O2, H21, and H30 melatonin sites and water molecules. The topological analysis of the H-bond electron density shows that the H-bond strength varies from weak to intermediate intensities, except for the O2 site – where it varies from weak to strong. The energetic aspect of the H-bonds was investigated using Helmholtz free energy, and the radial distribution function was employed to assess the mean residence time of the water atoms inside the first shell. The supramolecular arrangement of melatonin in the solid-state was investigated using the Hirshfeld surface technique. These findings deepen the knowledge of melatonin chemistry in the human body and help develop explanations for its biological activities.
Databáze: OpenAIRE