Dra. Gerli-Candia, Lorena

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.

Derivatives of parent molecules possess similar structural activity which makes them to be the topic of equal interest. In the present work, a naturally occurring acid eugenol and its co derivatives allyl-2-methoxy-4-nitrophenol and 5-Allyl-3-nitrobenzene-1,2-diol are theoretically investigated for their antioxidant role using density functional theory (DFT). Becke’s exchange correlation functional B3LYP and Minnesota functional M062X along with the basis set 6-311++G(d,p) are used to investigate the structural property through geometry optimization, frontier molecular orbital analysis, electrostatic potential analysis, and molecular descriptive parameters. Electron donating capability of the molecules is analyzed using frontier molecular orbital analysis and molecular descriptors. Molecular surface potential analysis facilitated to locate highest and lowest potential regions in these molecules. Hydrogen atom abstraction property (radical scavenging property) of the molecules is studied with the help of hydrogen atom transfer mechanism.