Dihydrochalcones: evaluation as novel radical scavenging antioxidants.
Dihydrochalcones are a family of bicyclic flavonoids, defined by the presence of two benzene rings joined by a saturated three carbon bridge. In the present study, we systematically examined the antioxidant activities of dihydrochalcones against the stable free radical (1,1-diphenyl-2-picrylhydrazyl) and lipid peroxidation in the erythrocyte membrane. All dihydrochalcones exhibited higher antioxidant activities than the corresponding flavanones. The (1)H NMR analysis indicated that the active dihydrochalcone has a time-averaged conformation in which the aromatic A ring is orthogonal to the carbonyl group, while the inactive dihydrochalcone such as 2'-O-methyl-phloretin has a strongly hydrogen-bonded phenolic hydroxyl group, suggestive of a coplanar conformation. A hydroxyl group at the 2'-position of the dihydrochalcone A ring, newly formed by reduction of the flavanone C ring, is an essential pharmacophore for its radical scavenging potential.
Laboratory of Food and Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan. yossan@agr.nagoya-u.ac.jp
Yoshimasa
Y
Nakamura
Shigeo
S
Watanabe
Nobuyuki
N
Miyake
Hiroyuki
H
Kohno
Toshihiko
T
Osawa
D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds; D002599:Chalcone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D047188:Chalcones; D004910:Erythrocyte Membrane / Q000737:chemistry; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006860:Hydrogen Bonding; D006900:Hydroxylation; D015227:Lipid Peroxidation / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010851:Picrates / Q000737:chemistry; D013329:Structure-Activity Relationship
D000975:Antioxidants; D001713:Biphenyl Compounds; D047188:Chalcones; D044950:Flavanones; D005419:Flavonoids; D016166:Free Radical Scavengers; D010851:Picrates; D002599:Chalcone; C004931:1,1-diphenyl-2-picrylhydrazyl; C015812:dihydrochalcone; C028610:flavanone