TY - JOUR
T1 - Free radical scavenging properties of guaiacol Oligomers
T2 - A Combined experimental and quantum study of the guaiacyl-moiety role
AU - Anouar, E.
AU - Calliste, C. A.
AU - Košinová, P.
AU - Di Meo, F.
AU - Duroux, J. L.
AU - Champavier, Y.
AU - Marakchi, K.
AU - Trouillas, P.
PY - 2009/12/17
Y1 - 2009/12/17
N2 - Natural polyphenols are known to exhibit a lot of different biological, properties, including antioxidant activity. For some polyphenols these activities are attributed to the presence of a guaiacol moiety. In the present paper we focus on the role of this moiety. For this purpose nine different compounds were enzymatically synthesized from, guaiacol. To elucidate the structure - activity relationship of these polyphenols, DFT-(PCM)B3P86/6- 311+G(2d,3pd)//(PCM)B3P86/6-31+G(d,p) calculations supported the experimental DPPH free radical, scavenging activities. The antioxidant activities were correlated to (i) O-H BDEs (bond dissociation enthalpies), (ii) BDED (BDE of a second H atom abstraction from the phenoxyradicals), (iii) spin density, (iv) HOMO (highest occupied molecular orbital) distribution, (v) IPs (ionization potentials), (vi) ΔG and ΔG free energies of HAT (H atom transfer), and (vii) HAT rate constants. BDED appeared to be the most important descriptor to understand the free radical scavenging ability of these compounds.
AB - Natural polyphenols are known to exhibit a lot of different biological, properties, including antioxidant activity. For some polyphenols these activities are attributed to the presence of a guaiacol moiety. In the present paper we focus on the role of this moiety. For this purpose nine different compounds were enzymatically synthesized from, guaiacol. To elucidate the structure - activity relationship of these polyphenols, DFT-(PCM)B3P86/6- 311+G(2d,3pd)//(PCM)B3P86/6-31+G(d,p) calculations supported the experimental DPPH free radical, scavenging activities. The antioxidant activities were correlated to (i) O-H BDEs (bond dissociation enthalpies), (ii) BDED (BDE of a second H atom abstraction from the phenoxyradicals), (iii) spin density, (iv) HOMO (highest occupied molecular orbital) distribution, (v) IPs (ionization potentials), (vi) ΔG and ΔG free energies of HAT (H atom transfer), and (vii) HAT rate constants. BDED appeared to be the most important descriptor to understand the free radical scavenging ability of these compounds.
UR - http://www.scopus.com/inward/record.url?scp=72649088603&partnerID=8YFLogxK
U2 - 10.1021/jp906285b
DO - 10.1021/jp906285b
M3 - Article
C2 - 19899743
AN - SCOPUS:72649088603
SN - 1089-5639
VL - 113
SP - 13881
EP - 13891
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 50
ER -