Antioxidant properties of several coumarin–chalcone hybrids from theoretical insights

Abstract

Density functional theory (DFT) and time-dependent formulation of DFT (TDDFT) have been employed to elucidate the structural characteristics, the antioxidant ability, and the UV-Vis absorption properties of a series of coumarin-chalcone derivatives recently synthesized. In addition, to investigate the role of adjacent hydroxyl groups on the antioxidant properties, five additional hybrids were designed and considered in this study. Different antioxidant mechanisms have been investigated. They are hydrogen atom transfer (HAT), electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET). Based on the obtained results, the HAT mechanism is proposed as the most important one for the antioxidant protection exerted by this class of compounds. The UV spectra of coumarin-chalcone hybrids are characterized by a band in the region between 300 and 450 nm arising from different electronic transitions. Our investigation confirms the antioxidant properties of these hybrids, and shows that poly-substitution of ring A enhances the antioxidant power of this class of compounds. One of the derivatives, designed in the present work, the 5,6,8-trihydroxy-7-methyl-3-(3 0 ,4 0 -dihydroxybenzoyl) coumarin, seems to be the most promising candidate as an antioxidant.Accordingly, our calculations strongly encourage the synthesis of coumarin-chalcone hybrids as an important strategy to develop novel compounds with improved antioxidant properties.

Quantum Chemical Investigation on the Antioxidant Activity of Neutral and Anionic Forms of Juglone: Metal Chelation and Its Effect on Radical Scavenging Activity

“…This shows that the sequential proton loss electron transfer is the preferred mechanism in water. This result is in good agreement with those found in the literature with the polar solvents [41][42][43][44][45][46][47][48]. In water, the Cu(II) chelate is found to be the most stable and the most reactive.…”

Antioxidant and spectral properties of chalcones and analogous aurones: Theoretical insights

“…The geometrical optimization and the frequency calculations have been carried out at DFT level employing the B3LYP functional coupled with the 6‐31G(d) basis set in gas phase. Previous papers on chalcones and other phenolic compounds have confirmed the efficiency of DFT‐B3LYP method in the calculation of physicochemical parameters elucidating radical scavenging activity. Unrestricted calculations were performed for the open‐shell systems, including radicals and radical cation species.…”

DFT calculations on molecular structures, HOMO–LUMO study, reactivity descriptors and spectral analyses of newly synthesized diorganotin(IV) 2‐chloridophenylacetohydroxamate complexes

“…The geometry of complexes were optimized in the gas phase using B3LYP/model in view of its good performance in geometry optimization and quite accurate prediction of reaction enthalpies with the triple zeta extended 6‐311++G(d,p) basis set for H, C, N, O, Cl, and Sn atoms without using any symmetry constraint. The molecular structures were visualized with the Avogadro software.…”