title: Antioxidant and quinone reductase-inducing constituents of black chokeberry (Aronia melanocarpa) fruits.
abstract: Using in vitro hydroxyl radical-scavenging and quinone reductase-inducing assays, bioactivity-guided fractionation of an ethyl acetate-soluble extract of the fruits of the botanical dietary supplement, black chokeberry (Aronia melanocarpa), led to the isolation of 27 compounds, including a new depside, ethyl 2-[(3,4-dihydroxybenzoyloxy)-4,6-dihydroxyphenyl] acetate (1), along with 26 known compounds (2-27). The structures of the isolated compounds were identified by analysis of their physical and spectroscopic data ([α](D), NMR, IR, UV, and MS). Altogether, 17 compounds (1-4, 9, 15-17, and 19-27) showed significant antioxidant activity in the hydroxyl radical-scavenging assay, with hyperin (24, ED(50) = 0.17 μM) being the most potent. The new compound (1, ED(50) = 0.44 μM) also exhibited potent antioxidant activity in this assay. Three constituents of black chokeberry fruits doubled quinone reductase activity at concentrations <20 μM, namely, protocatechuic acid [9, concentration required to double quinone reductase activity (CD) = 4.3 μM], neochlorogenic acid methyl ester (22, CD = 6.7 μM), and quercetin (23, CD = 3.1 μM).
authors.affiliation: Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, 500 West 12th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Ye
authors.initials: Y
authors.lastname: Deng
authors.forename: Chunhua
authors.initials: C
authors.lastname: Yuan
authors.forename: Li
authors.initials: L
authors.lastname: Pan
authors.forename: Heebyung
authors.initials: H
authors.lastname: Chai
authors.forename: William J
authors.initials: WJ
authors.lastname: Keller
authors.forename: A Douglas
authors.initials: AD
authors.lastname: Kinghorn
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry*; D010084:Oxidation-Reduction; D046936:Photinia / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D016660:NAD(P)H Dehydrogenase (Quinone)