Cargando…

Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study

Quinine is an alkaloid with powerful antimalarial activity, isolated from the bark of Peru’s cinchona trees. Quinidine is an erythro diastereoisomer of quinine also exhibiting antimalarial activity. Conformational studies performed so far had never identified conformers with intramolecular hydrogen...

Descripción completa

Detalles Bibliográficos
Autores principales: Bilonda, Mireille K., Mammino, Liliana
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155604/
https://www.ncbi.nlm.nih.gov/pubmed/28178218
http://dx.doi.org/10.3390/molecules22020245
_version_ 1783357930515464192
author Bilonda, Mireille K.
Mammino, Liliana
author_facet Bilonda, Mireille K.
Mammino, Liliana
author_sort Bilonda, Mireille K.
collection PubMed
description Quinine is an alkaloid with powerful antimalarial activity, isolated from the bark of Peru’s cinchona trees. Quinidine is an erythro diastereoisomer of quinine also exhibiting antimalarial activity. Conformational studies performed so far had never identified conformers with intramolecular hydrogen bonds (IHB). The current study shows the possibility of conformers with an IHB between the quinuclidine and quinoline moieties of these molecules. The study was performed at different levels of theory: Hartree Fock (HF) with the 6-31G(d,p) basis set, Density Functional Theory (DFT) with the B3LYP functional and the 6-31+G(d,p) basis set and Møller–Plesset Perturbation Theory (MP2) with the 6-31+G(d,p) basis set, to confirm the results. The results suggest that the stabilising effect of this IHB is weaker or comparable with respect to the stabilising effect of the preferred mutual orientation of the two moieties. Although the IHB-containing conformers may not be the lowest energy ones, their relative energy is sufficiently low for them to be included among the possible ones responsible for the compounds’ antimalarial activity.
format Online
Article
Text
id pubmed-6155604
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-61556042018-11-13 Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study Bilonda, Mireille K. Mammino, Liliana Molecules Article Quinine is an alkaloid with powerful antimalarial activity, isolated from the bark of Peru’s cinchona trees. Quinidine is an erythro diastereoisomer of quinine also exhibiting antimalarial activity. Conformational studies performed so far had never identified conformers with intramolecular hydrogen bonds (IHB). The current study shows the possibility of conformers with an IHB between the quinuclidine and quinoline moieties of these molecules. The study was performed at different levels of theory: Hartree Fock (HF) with the 6-31G(d,p) basis set, Density Functional Theory (DFT) with the B3LYP functional and the 6-31+G(d,p) basis set and Møller–Plesset Perturbation Theory (MP2) with the 6-31+G(d,p) basis set, to confirm the results. The results suggest that the stabilising effect of this IHB is weaker or comparable with respect to the stabilising effect of the preferred mutual orientation of the two moieties. Although the IHB-containing conformers may not be the lowest energy ones, their relative energy is sufficiently low for them to be included among the possible ones responsible for the compounds’ antimalarial activity. MDPI 2017-02-07 /pmc/articles/PMC6155604/ /pubmed/28178218 http://dx.doi.org/10.3390/molecules22020245 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Bilonda, Mireille K.
Mammino, Liliana
Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title_full Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title_fullStr Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title_full_unstemmed Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title_short Intramolecular Hydrogen Bonds in Conformers of Quinine and Quinidine: An HF, MP2 and DFT Study
title_sort intramolecular hydrogen bonds in conformers of quinine and quinidine: an hf, mp2 and dft study
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155604/
https://www.ncbi.nlm.nih.gov/pubmed/28178218
http://dx.doi.org/10.3390/molecules22020245
work_keys_str_mv AT bilondamireillek intramolecularhydrogenbondsinconformersofquinineandquinidineanhfmp2anddftstudy
AT mamminoliliana intramolecularhydrogenbondsinconformersofquinineandquinidineanhfmp2anddftstudy