title: Flavonoids from acai (Euterpe oleracea Mart.) pulp and their antioxidant and anti-inflammatory activities.
abstract: Five flavonoids, (2S,3S)-dihyrokaempferol 3-O-β-d-glucoside (1) and its isomer (2R,3R)-dihydrokaempferol 3-O-β-d-glucoside (2) , isovitexin (3), velutin (4) and 5,4'-dihydroxy-7,3',5'-trimethoxyflavone (5), were isolated from acai (Euterpe oleracea Mart.) pulp. The structures of these compounds were elucidated based upon spectroscopic and chemical analyses. To our knowledge, compounds 1, 2, 4 and 5 were identified from acai pulp for the first time. The in vitro antioxidant activities of these compounds were evaluated by the oxygen radial absorbance capacity (ORAC) assay. The ORAC values varied distinctly (4458.0-22404.5μmol Trolox equivalent (TE)/g) from 5,4'-dihydroxy-7,3',5'-trimethoxyflavone (5) to isovitexin (3) and were affected by the numbers/positions of hydroxyl groups, substitute groups, as well as stereo configuration. The anti-inflammatory effects of these compounds were screened by the secreted embryonic alkaline phosphatase (SEAP) reporter assay, which is designed to measure NF-κB activation. Velutin (4) was found to dose-dependently inhibit SEAP secretion in RAW-blue cells induced by LPS, with an IC50 value of 2.0μM. Velutin (4) also inhibited SEAP secretion induced by oxidised LDL, indicating potential athero-protective effects.
authors.affiliation: USDA Arkansas Children's Nutrition Centre, Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Kang
authors.affiliation: USDA Arkansas Children's Nutrition Centre, Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA.
authors.forename: Chenghui
authors.initials: C
authors.lastname: Xie
authors.affiliation: Shanghai Institute of Pharmaceutical Industry, 1320 W. Beijing Road, Shanghai 200040, China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Li
authors.affiliation: USDA Arkansas Children's Nutrition Centre, Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA.
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Nagarajan
authors.affiliation: AIBMR Life Science Inc., 4117 S Meridian, Puyallup, WA 98373, USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Schauss
authors.affiliation: Shanghai Institute of Pharmaceutical Industry, 1320 W. Beijing Road, Shanghai 200040, China. Electronic address: tongwu88@163.com.
authors.forename: Tong
authors.initials: T
authors.lastname: Wu
authors.affiliation: USDA Arkansas Children's Nutrition Centre, Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA. Electronic address: wuxianli@uams.edu.
authors.forename: Xianli
authors.initials: X
authors.lastname: Wu
keywords: Acai; Anti-inflammation; Antioxidant; Euterpe oleracea Mart.; Flavonoid