cis Oak lactone (w) trans Oak lactone (w) Acetic Acid (w, v) Isobutyric Acid (v) n-Butyric Acid (v) Isovaleric Acid (v) n-Valeric Acid (v) Glucose (w,v) Xylose (w,v) Fructose (w,v) Arabinose/Rhamnose (w,v) Gallic Acid (w) Ellagic acid (w,v) Phenol (w) Hydroxymethyl furfural (w) Guaiacol (w) p-Cresol (w) o-Cresol (w) Vanillin (w) Syringaldehyde (w) Coniferaldehyde (w) Sinapaldehyde (w) Vanillic acid (w) Syringic Acid (w) Scopoletin (w) Catechin (v) Epicatechin (v) Caffeic acid (v) 3,4 Dihydroxybenzoic acid
(v) Chlorogenic acid (v) Myricetin (v) Furfural (w)
The optimized geometries of the investigated dihydroxybenzoic acids and the corresponding radicals, anions, and radical cations were obtained by M05-2X method, in combination with 6-311++G(d,p) basis set [38, 39].
Comparing examined dihydroxybenzoic acids with the other phenolic acids, such as hydroxybenzoic acids and gallic acid [40, 41], it is clear that dihydroxybenzoic acids show quite good antioxidative properties.
The generally accepted approach based on the thermodynamic parameters (BDE, IP, and PA), related to the HAT, SPLET, and SET-PT mechanisms, was applied to six dihydroxybenzoic acids, their radicals, and the corresponding radical cations and anions.