title: Two new monoterpene glycosides from Qing Shan Lu Shui tea with inhibitory effects on leukocyte-type 12-lipoxygenase activity.
abstract: We evaluated the inhibitory effect of 12 Chinese teas on leukocyte-type 12-lipoxygenase (LOX) activity. Tea catechins such as epigallocatechin gallate have been known to exhibit leukocyte-type 12-LOX inhibition. Qing Shan Lu Shui, which contains lower catechin levels than the other tested teas, suppressed leukocyte-type 12-LOX activity. To characterize the bioactive components of Qing Shan Lu Shui, leukocyte-type 12-LOX inhibitory activity-guided fractionation of the aqueous ethanol extract of the tea was performed, resulting in the isolation of two new monoterpene glycosides: liguroside A (1) and B (2). The structures of compounds 1 and 2 were characterized as (2E,5E)-7-hydroperoxy-3,7-dimethyl-2,5-octadienyl-O-(α-L-rhamnopyranosyl)-(1″→3')-(4'″-O-trans-p-coumaroyl)-β-D-glucopyranoside and (2E,5E)-7-hydroperoxy-3,7-dimethyl-2,5-octa-dienyl- O-(α-L-rhamnopyranosyl)-(1″→3')-(4'″-O-cis-p-coumaroyl)-β-D-glucopyranoside, respectively, based on spectral and chemical evidence. Ligurosides A (1) and B (2) showed inhibitory effects on leukocyte-type 12-LOX activity, with IC50 values of 1.7 and 0.7 μM, respectively.
authors.affiliation: Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. hito@fhw.oka-pu.ac.jp
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Akemi
authors.initials: A
authors.lastname: Otsuki
authors.forename: Hitomi
authors.initials: H
authors.lastname: Mori
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Mai
authors.initials: M
authors.lastname: Kinoshita
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tsuji
authors.forename: Ding Zhi
authors.initials: DZ
authors.lastname: Fang
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects*; D016859:Lipoxygenase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology*; D013552:Swine; D013662:Tea / Q000737:chemistry*
chemical_list: D006027:Glycosides; D016859:Lipoxygenase Inhibitors; D039821:Monoterpenes; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D001092:Arachidonate 12-Lipoxygenase