Intramolecular hydrogen bond in biologically active o-carbonyl hydroquinones
Author
dc.contributor.author
Martínez Cifuentes, Maximiliano
Author
dc.contributor.author
Weiss López, Boris
es_CL
Author
dc.contributor.author
Santos, Leonardo S.
es_CL
Author
dc.contributor.author
Araya Maturana, Ramiro
es_CL
Admission date
dc.date.accessioned
2015-01-07T17:44:47Z
Available date
dc.date.available
2015-01-07T17:44:47Z
Publication date
dc.date.issued
2014
Cita de ítem
dc.identifier.citation
Molecules 2014, 19, 9354-9368
en_US
Identifier
dc.identifier.other
DOI: 10.3390/molecules19079354
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/121963
General note
dc.description
Artículo de publicación ISI
en_US
Abstract
dc.description.abstract
Intramolecular hydrogen bonds (IHBs) play a central role in the molecular
structure, chemical reactivity and interactions of biologically active molecules. Here, we
study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related
aromatic lactone, some of which have shown anticancer and antioxidant activity.
Experimental NMR data were correlated with theoretical calculations at the DFT and
ab initio levels. Natural bond orbital (NBO) and molecular electrostatic potential (MEP)
calculations were used to study the electronic characteristics of these IHB. As expected,
our results show that NBO calculations are better than MEP to describe the strength of the
IHBs. NBO energies (ΔEij
(2)) show that the main contributions to energy stabilization
correspond to LPσ* interactions for IHBs, O1
…O2-H2 and the delocalization LPπ* for
O2-C2 = Cα(β). For the O1
…O2-H2 interaction, the values of ΔEij
(2) can be attributed to the
difference in the overlap ability between orbitals i and j (Fij), instead of the energy difference
between them. The large energy for the LP O2π* C2 = Cα(β) interaction in the compounds
9-Hydroxy-5-oxo-4,8, 8-trimethyl-l,9(8H)-anthracenecarbolactone (VIII) and 9,10-dihydroxy-
4,4-dimethylanthracen-1(4H)-one (VII) (55.49 and 60.70 kcal/mol, respectively) when
compared with the remaining molecules (all less than 50 kcal/mol), suggests that the IHBs
in VIII and VII are strongly resonance assisted.
en_US
Patrocinador
dc.description.sponsorship
We are grateful to FONDECYT grants 1140753, FONDECYT/POSTDOCTORADO 3140286
(M.M-C) and ACT grant 1107.