title: Structure Elucidation of Procyanidins Isolated from Rhododendron formosanum and Their Anti-Oxidative and Anti-Bacterial Activities.
abstract: Rhododendron formosanum is an endemic species distributed in the central mountains of Taiwan. In this study, the biological activities of major procyanidins isolated from the leaf extract of R. formosanum were investigated. Four compounds, including two procyanidin dimers, procyanidin A1 (1) and B3 (2), and two procyanidin trimmers, procyanidin C4 (4) and cinnamtannin D1 (5), were isolated and identified on the basis of spectroscopic data. The structure of a new procyanidin dimer, rhodonidin A (3), was elucidated by 2D-NMR, CD spectrum and MS. The procyanidin trimmers and rhodonidin A are reported for the first time in Ericaceae. The biological activities of these procyanidins were evaluated using anti-bacterial and anti-oxidative assays. Only the new compound 3 demonstrated strong anti-bacterial activity against Staphylococcus aureus at an MIC value of 4 μg/mL. All compounds showed pronounced antioxidant activities and the activities are enhanced as the amount of OH groups in procyanidins increased. In conclusion, the pleiotropic effects of procyanidins isolated from the leaves of R. formosanum can be a source of promising compounds for the development of future pharmacological applications.
authors.affiliation: Research Center for Biodiversity, China Medical University, Taichung 40402, Taiwan. wangchaomin@mail.cmu.edu.tw.
authors.forename: Chao-Min
authors.initials: CM
authors.lastname: Wang
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan. yuanmh@mail.cmu.edu.tw.
authors.forename: Yuan-Man
authors.initials: YM
authors.lastname: Hsu
authors.affiliation: Research Center for Biodiversity, China Medical University, Taichung 40402, Taiwan. ah_giu@hotmail.com.
authors.forename: Yun-Lian
authors.initials: YL
authors.lastname: Jhan
authors.affiliation: Research Center for Biodiversity, China Medical University, Taichung 40402, Taiwan. csungjay@yahoo.com.tw.
authors.forename: Shang-Jie
authors.initials: SJ
authors.lastname: Tsai
authors.affiliation: Research Center for Biodiversity, China Medical University, Taichung 40402, Taiwan. flyalonewithme9147@gmail.com.
authors.forename: Shi-Xun
authors.initials: SX
authors.lastname: Lin
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan. adaga0806@hotmail.com.
authors.forename: Chiu-Hsian
authors.initials: CH
authors.lastname: Su
authors.affiliation: Research Center for Biodiversity, China Medical University, Taichung 40402, Taiwan. choumasa@mail.cmu.edu.tw.|Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan. choumasa@mail.cmu.edu.tw.|Department of Life Sciences, National Cheng Kung University, Tainan 701, Taiwan. choumasa@mail.cmu.edu.tw.
authors.forename: Chang-Hung
authors.initials: CH
authors.lastname: Chou
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000037:antagonists & inhibitors / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010851:Picrates / Q000037:antagonists & inhibitors / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D029793:Rhododendron / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013329:Structure-Activity Relationship; D013624:Taiwan
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; D044945:Proanthocyanidins; C000606931:rhodonidin A; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: anti-bacterial; antioxidant; cinnamtannin D1; procyanidin A1; procyanidin B3; procyanidin C4; rhodonidin A