THEORETICAL INVESTIGATION OF THE MOLECULAR STRUCTURE AND SPECTROSCOPIC PROPERTIES OF OXICAMS
A. G. Pacheco1, G. Salgado-Moran2, L. Gerli-Candia3, R. Ramirez-Tagle4, D. Glossman-Mitnik5, A. Misra6, A. F. de Carvalho Alcantara7
1Instituto Federal de Educacao Ciencia e Tecnologia do Sul de Minas Gerais, Inconfidentes, Brasil 2Universidad Andres Bello, Concepcion, Chile 3Universidad Catolica de la Santisima Concepcion, Concepcion, Chile 4Universidad Bernardo O'Higgins, Santiago, Chile 5Centro de Investigacion em Materiales Avanzados, Chihuahua, Mexico 6Vidyasagar University, Midnapore, India 7Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
Keywords: nonsteroidal anti-inflammatory drugs, chemical properties, spectroscopic analysis, density functional theory
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs and have multiple therapeutic uses. These drugs are predominantly used for the treatment of musculoskeletal diseases because of their analgesic, antipyretic, and antiplatelet activities. Oxicams constitute an interesting class of organic compounds and have been investigated in the search for new analgesic and anti-inflammatory drugs. In the present work, a theoretical investigation of the molecular structure and spectroscopic properties of a series of five oxicams in different solvents was performed using density functional theory (DFT) methods. The geometric optimizations of the oxicams were carried out using the M06 density functional and the CBSB7 basis set. The infrared data were all obtained at the same theoretical level. The UV-Vis absorption and NMR data of some oxicams were calculated using the DFT and CBSB3 basis sets. The analysis of structural parameters, particularly the bond length and spectroscopic data, indicated that interactions occurred between the hydrogen bond types for 4-meloxicam, isoxicam, and normeloxicam. Stereoelectronic interactions caused by the substitution of alkyl groups caused the bond lengths to elongate. Similarly, the substitution of heteroatoms, such as nitrogen, sulfur, or oxygen, increased the bond lengths and angular stresses.
|