Elucidation of antioxidant properties of wood bark derived saturated diarylheptanoids: a comprehensive (DFT-supported) understanding.
A series of diarylheptanoids, namely 1,7-bis-(3,4-dihydroxyphenyl)-heptan-3-one-5-O-D-xylopyranoside (oregonin), 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-β-D-xylopyranoside and 1,7-bis-(4-hydroxyphenyl)-heptane-3-one-5-O-β-D-glucopyranoside (platyphylloside), were isolated from the bark of alder family trees, a species widely spread over in Europe. As antioxidants, these natural polyphenols have a promising potential in various fields of application, but their redox reactivity is insufficiently characterized. In this work, their antioxidant activity is described using assays based on DPPH and ABTS(+) radical scavenging, oxygen anion radicals (O2(-)) quenching. The standardized ORAC assay was also achieved, which measures the capacity to protect fluorescent molecules against oxidative degradation. The measured antioxidant activity was higher than that of the well-known antioxidant and biologically active diarylheptanoid curcumin. Molecular modeling was used to rationalize the differences in activity and the mechanisms of action. Thermodynamic descriptors mainly O-H bond dissociation enthalpies (BDEs) establish a clear structure-activity relationship.
University of Latvia, Faculty of Chemistry, K. Valdemara Str. 48, LV-1013, Riga, Latvia; Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006, Riga, Latvia. Electronic address: jevgenijaponomarenko@inbox.lv.
Jevgenija
J
Ponomarenko
Inserm UMR-S850, Faculté de Pharmacie, Université de Limoges, 2 rue du Docteur Marcland, Limoges, France; Service de Chimie des Matériaux Nouveaux, Université de Mons - UMONS, Place du Parc 20, 7000 Mons, Belgium; Regional Center of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc, Czech Republic.
Patrick
P
Trouillas
Inserm UMR-S850, Faculté de Pharmacie, Université de Limoges, 2 rue du Docteur Marcland, Limoges, France.
Nicolas
N
Martin
Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006, Riga, Latvia.
Tatyana
T
Dizhbite
Riga Stradin's University, Dzirciema Str. 16, LV-1007, Riga, Latvia.
Jelena
J
Krasilnikova
Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006, Riga, Latvia.
Galina
G
Telysheva
D029661:Alnus / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry*; D036381:Diarylheptanoids / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014934:Wood / Q000737:chemistry*
D000975:Antioxidants; D036381:Diarylheptanoids
ABTS(+); Antioxidants; DPPH(); Diarylheptanoids; Electron transfer; Grey alder (Alnus incana) bark; Ionization potentials; Molecular modeling; ORAC; O–H bond dissociation enthalpies; Structure–activity relationship; Superoxide