2017. 58, 2 – UDC 541.6:543.422:548:737 THEORETICAL INVESTIGATION OF THE MOLECULAR STRUCTURE AND SPECTROSCOPIC PROPERTIES OF OXICAMS A.G. Pacheco1, G. Salgado-Morбn2, L. Gerli-Candia3, R. Ramнrez-Tagle4, D. Glossman-Mitnik5, A. Misra6, A.F. de Carvalho Alcвntara7 1Instituto Federal de Educaзгo Ciкncia e Tecnologia do Sul de Minas Gerais, Inconfidentes, Brasil 2Departamento de Ciencias, Facultad de Ciencias Exactas, Universidad Andrйs Bello, Concepciуn, Chile 3Departamento de Quнmica Ambiental, Facultad de Ciencias, Universidad Catуlica de la Santнsima Concepciуn, Concepciуn, Chile 4Facultad de Ingenierнa, Ciencia y Tecnologнa, Universidad Bernardo OHiggins, Santiago, Chile E-mail: rramirez@ubo.cl 5Laboratorio Virtual NANOCOSMOS, Centro de Investigaciуn em Materiales Avanzados, Chihuahua, Mexico 6Vidyasagar University, Midnapore, India 7Universidade Federal de Minas Gerais, Belo Horizonte, Brasil Received June, 23, 2015 Revised — December, 30, 2015 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. <...> 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. <...> DOI: 10.15372/JSC20170206 Keywords: nonsteroidal anti-inflammatory drugs, chemical properties, spectroscopic analysis, density functional theory. <...> INTRODUCTION Nonsteroidal anti-inflammatory drugs (NSAIDs <...>