TY  - JOUR
AU  - Milanović, Ziko
AU  - Dimic, Dusan
AU  - Žižić, Milan
AU  - Milenković, Dejan
AU  - Marković, Zoran
AU  - Avdović, Edina
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1504
AB  - Coumarin derivatives have proven beneficial biological activities, but the mechanism of their radical scavenging potency is not fully understood. In this study, the antiradical capacity of two newly synthesized 4,7-dihydroxycoumarin derivatives: (E)-3-(1-((3-hydroxy-4-methoxyphenyl)amino)-ethylidene)-2,4-dioxochroman-7-yl acetate (A-3OH) and (E)-3-(1-((4-hydroxy-3-methoxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A-4OH) towards HO center dot were examined by Electron Paramagnetic Resonance (EPR) Spectroscopy and Density Functional Theory (DFT). The compounds were fully characterized by the elemental microanalysis, IR, and NMR spectroscopies. The effect of pH on the acid-base equilibria is separately discussed and the predominant species at the physiological pH were determined. Several common mechanisms (Hydrogen Atom Transfer (HAT), Single-Electron Transfer followed by Proton Transfer (SET-PT), Sequential Proton Loss followed by Electron Transfer (SPLET), Radical Adduct Formation (RAF), and Intramolecular Hydrogen Atom Abstraction (iHAA)) of radical scavenging were investigated based on thermodynamic and kinetic parameters. EPR results indicated that both compounds significantly reduce the amount of present HO center dot. The results of the kinetic DFT study demonstrated that both compounds predominantly exhibit antiradical capacity through HAT and SPLET mechanisms. The estimated overall rate constants (k(overall)) proved that A-4OH shows better antioxidant capacity than A-3OH which is well-correlated with the results obtained by EPR measurement.
PB  - MDPI, Basel
T2  - International Journal of Molecular Sciences
T1  - Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study
IS  - 24
VL  - 22
DO  - 10.3390/ijms222413273
ER  - 

@article{
author = "Milanović, Ziko and Dimic, Dusan and Žižić, Milan and Milenković, Dejan and Marković, Zoran and Avdović, Edina",
year = "2021",
abstract = "Coumarin derivatives have proven beneficial biological activities, but the mechanism of their radical scavenging potency is not fully understood. In this study, the antiradical capacity of two newly synthesized 4,7-dihydroxycoumarin derivatives: (E)-3-(1-((3-hydroxy-4-methoxyphenyl)amino)-ethylidene)-2,4-dioxochroman-7-yl acetate (A-3OH) and (E)-3-(1-((4-hydroxy-3-methoxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate (A-4OH) towards HO center dot were examined by Electron Paramagnetic Resonance (EPR) Spectroscopy and Density Functional Theory (DFT). The compounds were fully characterized by the elemental microanalysis, IR, and NMR spectroscopies. The effect of pH on the acid-base equilibria is separately discussed and the predominant species at the physiological pH were determined. Several common mechanisms (Hydrogen Atom Transfer (HAT), Single-Electron Transfer followed by Proton Transfer (SET-PT), Sequential Proton Loss followed by Electron Transfer (SPLET), Radical Adduct Formation (RAF), and Intramolecular Hydrogen Atom Abstraction (iHAA)) of radical scavenging were investigated based on thermodynamic and kinetic parameters. EPR results indicated that both compounds significantly reduce the amount of present HO center dot. The results of the kinetic DFT study demonstrated that both compounds predominantly exhibit antiradical capacity through HAT and SPLET mechanisms. The estimated overall rate constants (k(overall)) proved that A-4OH shows better antioxidant capacity than A-3OH which is well-correlated with the results obtained by EPR measurement.",
publisher = "MDPI, Basel",
journal = "International Journal of Molecular Sciences",
title = "Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study",
number = "24",
volume = "22",
doi = "10.3390/ijms222413273"
}

Milanović, Z., Dimic, D., Žižić, M., Milenković, D., Marković, Z.,& Avdović, E.. (2021). Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study. in International Journal of Molecular Sciences
MDPI, Basel., 22(24).
https://doi.org/10.3390/ijms222413273

Milanović Z, Dimic D, Žižić M, Milenković D, Marković Z, Avdović E. Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study. in International Journal of Molecular Sciences. 2021;22(24).
doi:10.3390/ijms222413273 .

Milanović, Ziko, Dimic, Dusan, Žižić, Milan, Milenković, Dejan, Marković, Zoran, Avdović, Edina, "Mechanism of Antiradical Activity of Newly Synthesized 4,7-Dihydroxycoumarin Derivatives-Experimental and Kinetic DFT Study" in International Journal of Molecular Sciences, 22, no. 24 (2021),
https://doi.org/10.3390/ijms222413273 . .