title: Structural elucidation and cellular antioxidant activity evaluation of major antioxidant phenolics in lychee pulp.
abstract: Lychee pulp contains phenolic compounds that are strong antioxidants, but the identities of the major antioxidants present are unknown. In the present study, the major contributors to the antioxidant activity of fresh lychee pulp were identified and their cellular antioxidant activities were investigated. Aqueous acetone extracts of lychee pulp were fractionated on polyamide resin, and those fractions with the largest antioxidant and radical scavenging activities were selected using cellular antioxidant activity and oxygen radical absorbance capacity assays. Three compounds that were major contributors to the antioxidant activity in these fractions were obtained by reverse-phase preparative HPLC and identified as quercetin 3-O-rutinoside-7-O-α-L-rhamnosidase (quercetin 3-rut-7-rha), quercetin 3-O-rutinoside (rutin) and (-)-epicatechin using NMR spectroscopy, HMBC, and ESI-MS spectrometry. The concentration of quercetin 3-rut-7-rha was 17.25mg per 100g of lychee pulp fresh weight. This is the first report of the identification and cellular antioxidant activity of quercetin 3-rut-7-rha from lychee pulp.
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China; Department of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Dongxiao
authors.initials: D
authors.lastname: Su
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Ti
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
authors.forename: Ruifen
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China. Electronic address: mwzhh@vip.tom.com.
authors.forename: Mingwei
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
authors.forename: Zhengchen
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Key Laboratory of Functional Foods, Ministry of Agriculture, Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Guo
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D032125:Litchi / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis*
chemical_list: D000975:Antioxidants; D010636:Phenols
keywords: Antioxidant activity; Cellular antioxidant activity; Lychee; Oxygen radical absorbance capacity; Phenolics; Quercetin 3-O-rutinoside-7-O-α-l-rhamnosidase