TY - JOUR
T1 - Hydroxyl radical reactions of (4-hydroxy, 3-methoxy-5-bromophenyl) pentenone, a curcuminoid antioxidant
AU - Guha, S.N.
AU - Priyadarsini, K.I.
AU - Devasagayam, T.P.A.
AU - [No Value], Sreejayan
AU - Rao, M.N.A.
A2 - Mukherjee T., Sapre A.V.
N1 - cited By 8; Conference of Proceedings of the 1996 Trombay Symposium on Radiation and Photochemistry ; Conference Date: 8 January 1996 Through 12 January 1996; Conference Code:46023
PY - 1997
Y1 - 1997
N2 - Reactions of hydroxyl radical (OH) with (4-hydroxy, 3-methoxy-5-bromophenyl) pentenone (BP), were studied in aqueous solutions using the pulse radiolysis technique. BP, showed high reactivity with OH and gave rise to different radicals at different pHs. On the basis of our studies of this compound with more specific oxidizing radicals such as N3, Tl(II), etc. it was inferred that hydroxyl radicals lead mainly to one electron oxidation at pH 10 where BP is present as the phenoxide ion. Whereas at pH 5 (phenolic form), oxidation is only a minor process, the major being the formation of addition products. The one electron reduction potential of the phenoxyl radical derived from BP at pH 6 was estimated using promethazine as the redox standard to be 910 ± 15 mV vs NHE. The physicochemical properties of the phenoxyl radicals were compared with those of the other curcuminoid antioxidants. Reactions of hydroxyl radical (OH) with (4-hydroxy, 3-methoxy-5-bromophenyl) pentenone (BP), were studied in aqueous solutions using the pulse radiolysis technique. BP, showed high reactivity with OH and gave rise to different radicals at different pHs. On the basis of our studies of this compound with more specific oxidizing radicals such as N3, Tl(II), etc. it was inferred that hydroxyl radicals lead mainly to one electron oxidation at pH 10 where BP is present as the phenoxide ion. Whereas at pH 5 (phenolic form), oxidation is only a minor process, the major being the formation of addition products. The one electron reduction potential of the phenoxyl radical derived from BP at pH 6 was estimated using promethazine as the redox standard to be 910±15 mV vs NHE. The physicochemical properties of the phenoxyl radicals were compared with those of the other curcuminoid antioxidants.
AB - Reactions of hydroxyl radical (OH) with (4-hydroxy, 3-methoxy-5-bromophenyl) pentenone (BP), were studied in aqueous solutions using the pulse radiolysis technique. BP, showed high reactivity with OH and gave rise to different radicals at different pHs. On the basis of our studies of this compound with more specific oxidizing radicals such as N3, Tl(II), etc. it was inferred that hydroxyl radicals lead mainly to one electron oxidation at pH 10 where BP is present as the phenoxide ion. Whereas at pH 5 (phenolic form), oxidation is only a minor process, the major being the formation of addition products. The one electron reduction potential of the phenoxyl radical derived from BP at pH 6 was estimated using promethazine as the redox standard to be 910 ± 15 mV vs NHE. The physicochemical properties of the phenoxyl radicals were compared with those of the other curcuminoid antioxidants. Reactions of hydroxyl radical (OH) with (4-hydroxy, 3-methoxy-5-bromophenyl) pentenone (BP), were studied in aqueous solutions using the pulse radiolysis technique. BP, showed high reactivity with OH and gave rise to different radicals at different pHs. On the basis of our studies of this compound with more specific oxidizing radicals such as N3, Tl(II), etc. it was inferred that hydroxyl radicals lead mainly to one electron oxidation at pH 10 where BP is present as the phenoxide ion. Whereas at pH 5 (phenolic form), oxidation is only a minor process, the major being the formation of addition products. The one electron reduction potential of the phenoxyl radical derived from BP at pH 6 was estimated using promethazine as the redox standard to be 910±15 mV vs NHE. The physicochemical properties of the phenoxyl radicals were compared with those of the other curcuminoid antioxidants.
U2 - 10.1016/S0969-806X(96)00104-1
DO - 10.1016/S0969-806X(96)00104-1
M3 - Article
SN - 0969-806X
VL - 49
SP - 43
EP - 46
JO - Radiation Physics and Chemistry
JF - Radiation Physics and Chemistry
IS - 1
ER -