title: Isolation and evaluation of the radical-scavenging activity of the antioxidants in the leaves of an edible plant, Mallotus japonicus.
abstract: The antioxidative properties of a hot water extract of the leaves of Mallotus japonicus were evaluated. The extract had a high phenolic content and strong antioxidative activity, compared with green tea, rooibos tea, and red wine. Six phenolic compounds were isolated as antioxidative components by HPLC. They were identified as mallotinic acid, mallotusinic acid, corilagin, geraniin, rutin, and ellagic acid. These antioxidative compounds were subjected to DPPH radical-scavenging, superoxide radical-scavenging, and hydroxyl radical-scavenging assays, and compared with other antioxidative compounds. Four of the compounds, mallotinic acid, mallotusinic acid, corilagin and geraniin, exhibited much stronger antioxidative activity than gallic acid, rutin, ellagic acid, quercetin, and chlorogenic acid, and were as active as epigallocatechin gallate (EGCG), a strong antioxidant in green tea. Mallotus japonicus leaves are an excellent source of strong natural antioxidative materials.
authors.affiliation: Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan; Department of Biological Chemistry, Faculty of Agriculture, and Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan. Electronic address: tabata-hiromasa@shimane-iit.jp.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tabata
authors.affiliation: Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Katsube
authors.affiliation: Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan.
authors.forename: Terumi
authors.initials: T
authors.lastname: Tsuma
authors.affiliation: Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Ohta
authors.affiliation: Shimane Institute for Industrial Technology, 1 Hokuryo-cho, Matsue, Shimane 690-0816, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Imawaka
authors.affiliation: Department of Biological Chemistry, Faculty of Agriculture, and Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Utsumi
keywords: Antioxidant; DPPH radical; Folin–Ciocalteu; Hydroxyl radical; Mallotus japonicus; Superoxide radical