Antioxidative phenolic compounds isolated from almond skins (Prunus amygdalus Batsch).
Nine phenolic compounds were isolated from the ethyl acetate and n-butanol fractions of almond (Prunus amygdalus) skins. On the basis of NMR data, MS data, and comparison with the literature, these compounds were identified as 3'-O-methylquercetin 3-O-beta-D-glucopyranoside (1); 3'-O-methylquercetin 3-O-beta-D-galactopyranoside (2); 3'-O-methylquercetin 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (3); kaempferol 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (4); naringenin 7-O-beta-D-glucopyranoside (5); catechin (6); protocatechuic acid (7); vanillic acid (8); and p-hydroxybenzoic acid (9). All of these compounds have been isolated from almond skins for the first time. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activities for compounds 1-9 were determined. Compounds 6 and 7 show very strong DPPH radical scavenging activity. Compounds 1-3, 5, 8, and 9 show strong activity, whereas compound 4 has very weak activity.
Sang
Shengmin
S
Department of Food Science and Center for Advanced Food Technology, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901-8520, USA.
Lapsley
Karen
K
Jeong
Woo-Sik
WS
Lachance
Paul A
PA
Ho
Chi-Tang
CT
Rosen
Robert T
RT
D020001:1-Butanol; D000085:Acetates; D000975:Antioxidants / Q000302:isolation & purification*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification; D044948:Flavonols; D009682:Magnetic Resonance Spectroscopy; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification*; D018514:Plant Structures / Q000737:chemistry*; D027861:Prunus / Q000737:chemistry*; D014020:Tissue Extracts / Q000737:chemistry
D000085:Acetates; D000975:Antioxidants; D005419:Flavonoids; D044948:Flavonols; D010636:Phenols; D014020:Tissue Extracts; C007650:ethyl acetate; D020001:1-Butanol