title: Flavonoids from Machilus japonica stems and their inhibitory effects on LDL oxidation.
abstract: Stems of Machilus japonica were extracted with 80% aqueous methanol (MeOH) and the concentrated extract was successively extracted with ethyl acetate (EtOAc), normal butanol (n-BuOH), and water. Six flavonoids were isolated from the EtOAc fraction: (+)-taxifolin, afzelin, (-)-epicatechin, 5,3'-di-O-methyl-(-)-epicatechin, 5,7,3'-tri-O-methyl-(-)-epicatechin, and 5,7-di-O-methyl-3',4'-methylenedioxyflavan-3-ol. The chemical structures were identified using spectroscopic data including NMR, mass spectrometry and infrared spectroscopy. This is the first report of isolation of these six compounds from M. japonica. The compounds were evaluated for their diphenyl picryl hydrazinyl scavenging activity and inhibitory effects on low-density lipoprotein oxidation. Compounds 1 and 3-6 exhibited DPPH antioxidant activity equivalent with that of ascorbic acid, with half maximal inhibitory concentration (IC50) values of 0.16, 0.21, 0.17, 0.15 and 0.07 mM, respectively. The activity of compound 1 was similar to the positive control butylated hydroxytoluene, which had an IC50 value of 1.9 µM, while compounds 3 and 5 showed little activity. Compounds 1, 3, and 5 exhibited LDL antioxidant activity with IC50 values of 2.8, 7.1, and 4.6 µM, respectively.
authors.affiliation: Center, Seoul Cosmetics Co., Ltd., Incheon 443-749, Korea. skincare@seoulcos.co.kr.
authors.forename: Se-Jin
authors.initials: SJ
authors.lastname: Joo
authors.affiliation: Laboratory of Natural Products Chemistry, Graduate School of Oriental Medicinal Materials Biotechnology, Kyung Hee University, Yongin 446-701, Korea. bluedew011@hanmail.net.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Laboratory of Natural Products Chemistry, Graduate School of Oriental Medicinal Materials Biotechnology, Kyung Hee University, Yongin 446-701, Korea. wlgo3411@hanmail.net.
authors.forename: Ji-Hae
authors.initials: JH
authors.lastname: Park
authors.affiliation: Laboratory of Natural Products Chemistry, Graduate School of Oriental Medicinal Materials Biotechnology, Kyung Hee University, Yongin 446-701, Korea. kukuku1555@khu.ac.kr.
authors.forename: Jin-Gyeong
authors.initials: JG
authors.lastname: Cho
authors.affiliation: National Research Laboratory of Lipid Metabolism & Atherosclerosis, KRIBB, Daejeon 305-806, Korea. bsloaucl@naver.com.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Kang
authors.affiliation: National Research Laboratory of Lipid Metabolism & Atherosclerosis, KRIBB, Daejeon 305-806, Korea. tsjeong@kribb.re.kr.
authors.forename: Tae-Sook
authors.initials: TS
authors.lastname: Jeong
authors.affiliation: Research & Development Center, GFC Co., Ltd., Suwon 443-813, Korea. cmkorea@unitel.co.kr.
authors.forename: Hee Cheol
authors.initials: HC
authors.lastname: Kang
authors.affiliation: Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, RDA, Eumseong 369-873, Korea. dylee0809@korea.kr.
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Lee
authors.affiliation: Center, Seoul Cosmetics Co., Ltd., Incheon 443-749, Korea. hskim@seoulcos.co.kr.
authors.forename: Hack-Soo
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Cosmetic Business R&D Service Center, Graduate School, Ajou University, Suwon 443-749, Korea. sybyun@ajou.ac.kr.
authors.forename: Sang-Yo
authors.initials: SY
authors.lastname: Byun
authors.affiliation: Laboratory of Natural Products Chemistry, Graduate School of Oriental Medicinal Materials Biotechnology, Kyung Hee University, Yongin 446-701, Korea. nibaek@khu.ac.kr.
authors.forename: Nam-In
authors.initials: NI
authors.lastname: Baek
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D019770:Lauraceae / Q000737:chemistry* / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein