Naslov
Why does ferulic acid scavenge radicals more effectively than caffeic acid? A DFT study.

Autori
Amić, Ana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Computational Chemistry Day Book of Abstracts / - Zagreb : Prirodoslovno-matematički fakultet Sveučilišta u Zagrebu, 2018, 13-14

ISBN
978-953-6076-45-1

Skup
Computational Chemistry Day 2018

Mjesto i datum
Zagreb, Hrvatska, 12.05.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
polyphenols, DFT, dHAT, dSPLET, radical scavenging

Sažetak
Caffeic acid (CA) and ferulic acid (FA) are widespread in plant kingdom and are constituents of a diet rich in fruits and vegetables. Both acids are also abundant colon catabolites of diverse polyphenolic compounds and may appear in systemic circulation in low micromolar concentrations. Due to high bioavailability, they possess potency to scavenge excess of intracellular radical species and thus may help in supressing age- related diseases [1]. In vitro assays indicated FA as more efficient radical scavenger than CA [2]. It is an unexpected result because CA possesses catechol group (two vicinal OHs) which is a well-known powerful antiradical moiety. FA possesses guaiacyl group (vicinal OH and OCH3) for which the role in radical scavenging is only scarcely investigated [3]. This research tries to explore the antioxidant mechanisms which enable better antiradical activity of FA in comparison with CA. DFT calculations of thermodynamics of double hydrogen atom transfer (dHAT) and double sequential proton loss electron transfer (dSPLET) were performed in water and pentyl ethanoate as solvents at SMD/M06-2X/6- 311++G(d, p) level of theory. Obtained results for dHAT mechanism are depictured below. Contrary to experimental results, single HAT mechanism, i.e., BDE1 value indicates CA as better antioxidant. Experimental findings can be explained by considering dHAT: pathway via guaiacyl moiety of FA is less energy demanding than via catechol group of CA. It is known that lower BDE value is related to faster radical- trapping kinetics. These facts could explain higher antiradical activity of FA. Analogous results are obtained for dSPLET mechanism. Thus, the role of guaiacyl moiety in radical- trapping should not be neglected, as mainly was the case previously. In addition, Gibbs free energy changes in studied mechanisms indicate both acids as effective scavengers of a set of ten radicals. Again, FA is the more potent radical scavenger.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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