Three-component reaction involving isoquinoline and dimethyl acethylenedicarboxylate in the presence of indole: Theoretical and experimental investigations of the reaction mechanism

The reaction kinetics among isoquinoline, dimethyl acetylenedicarboxylate, and indole (as NH-acid) were investigated using ultraviolet (UV) spectrophotometry. The reaction rate equation was obtained, the dependence of the reaction rate on different reactants was determined, and the overall rate constant ( kov) was calculated. By studying the effects of solvent, temperature, and concentration on the reaction rate, some useful information was obtained. A logical mechanism consistent with the experimental observations was proposed. Also, comprehensive theoretical studies were performed to evaluate the potential energy surfaces of all structures that participated in the reaction mechanism. Finally, the proposed mechanism was confirmed by the obtained results and the probable and logical reaction paths and also a correct product configuration were suggested based on the theoretical results.

Potential of graphene oxide as a drug delivery system for Sumatriptan: a detailed density functional theory study

The adsorption property of Sumatriptan drug onto graphene oxide (GO) was studied using density functional theory (DFT) calculations. All possible initial positions of drug adsorption were considered to find out which one is energetically favorable. According to the achieved findings, the stronger interactions occurred between the positively polarized parts of the Sumatriptan (i.e. hydrogen atoms of the-OH and -NH parts) and negatively polarized oxygen atoms of the GO. The presence of non-covalent interactions of GO and Sumatriptan was confirmed based on the determined geometrical parameters, electronic structure analysis results, and adsorption energies. Different parameters such as frontier molecular orbital (FMO), natural bond orbital (NBO), dipole moment, and solation energy were investigated. Global indices such as hardness, softness, chemical potential, and electrophilicity of all systems were calculated and compared. The adsorption energy values were determined within the range of -8.39 to -10.59 kcal/mol (-1.87 to -5.67 BSSE corrected) in the water solvent for different adsorption geometries. The obtained results show that GO can act as a promising carrier/sensor for Sumatriptan drug in practical application.Communicated by Ramaswamy H. Sarma.