Radiolytic transformation of 2,2',4'-trihydroxychalcone.
Radiolysis of 2,2',4'-trihydroxychalcone, a natural antioxidant present in fruit and vegetables, was performed in ethanol in the absence or in the presence of dioxygen. The degradation process of chalcone was followed in de-aerated solution by HPLC, NMR, FAB-LSIMS mass spectroscopy and analytical TLC. Under anaerobic conditions, six new products (three couples of diastereoisomers) were identified. Four of them kept the chalcone skeleton with OCH(2)CH(3), CH(OH)CH(3) and H substitutions on C(alpha) and C(beta). Thus the target was the alpha-beta double bond on which ethanol radicals were added. The two other compounds were formed in a second stage and exhibited a cyclization between the substituent on C(beta) and the carbonyl group. In the presence of dioxygen, these reactions were prevented and chalcone was protected. This study was the first step toward understanding of the behavior chalcone in irradiated fruits and vegetables.
Mokrini
Redouane
R
EA 1085 "Biomolécules et Cibles Cellulaires Tumorales," 87025 Limoges Cedex, France.
Trouillas
Patrick
P
Kaouadji
Mourad
M
Champavier
Yves
Y
Houée-Lévin
Chantal
C
Calliste
Claude-Alain
CA
Duroux
Jean-Luc
JL
D002599:Chalcone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000528:radiation effects; D047188:Chalcones; D004307:Dose-Response Relationship, Radiation; D000431:Ethanol / Q000737:chemistry* / Q000528:radiation effects; D010100:Oxygen / Q000737:chemistry* / Q000528:radiation effects; D011675:Pulse Radiolysis; D011829:Radiation Dosage
C110093:2,4,2'-trihydroxychalcone; D047188:Chalcones; D000431:Ethanol; D002599:Chalcone; D010100:Oxygen