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oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/141572026-10-18T20:39:22Zopenairedrivercom_ebyu_10000col_ebyu_10001

Chemical constituents isolated from Rhododendron ungernii with antioxidant profileDede, EmineGenc, NusretElmastas, MahfuzAksit, HuseyinErenler, RamazanActive compoundsAntioxidantBiological activitiesFlavonoidsPhenolic compoundsRhododendron ungerniicatechin 7 o glucosidefarrerolhyperinmyricetinplant extractquercetinquercetin 3 beta xylosideRhododendron ungernii extractunclassified drugantioxidant activityantioxidant assayArticlechemical compositiondrug identificationdrug isolationdrug structureflowerpriority journalRhododendronshadeBackground: Plant in Rhododendron genus that contains phenolic compounds has been used in traditional medicine and revealed considerable biological activities. Objective: Isolation and identification of antioxidant natural products from Rhododendron ungernii. Methods: Rhododendron ungernii Trautv. flowers were collected and dried in shade. The dried flowers were extracted with methanol for 3 days. The solvent was removed by reduced pressure to yield the extract which was subjected to column chromatography (Sephadex LH-20, C18 reversed phase column) to isolate catechin-7-O-glucoside (1), quercetin-3-O-β-galactoside (2), quercetin-3-O-β-xyloside (3), farrerol (4), myricetin (5), and quercetin (6). The structures of isolated compounds were elucidated by spectroscopic methods such as 1D-NMR, 2D-NMR, and LC-TOF/MS. DPPH• scavenging effect, ABTS•+ scavenging activity, and reducing power (FRAP) were performed for antioxidant assays of isolated natural compounds. Results: Isolated flavonoids displayed the outstanding antioxidant activities. Catechin-7-O-glucoside (1) and quercetin-3-O-β-galactoside (2) (IC50, 3.66 µg/mL) had the most DPPH• scavenging effect among the compounds. The highest ABTS•+ scavenging activity (IC50, 1.41 µg/mL) and reducing power effect (6.05 mmol TE/g comp) were observed for myricetin (5). Conclusion: R. ungernii extract and isolated compounds could be a promising antioxidant for food and pharmaceutical industries. © 2019 Bentham Science Publishers.Bentham Science Publishers2019Articlehttps://rdlopen.rawdatalibrary.net/r/ebyu/14157https://doi.org/10.2174/22103155086661810241148122210-3155enNatural Products Journalinfo:eu-repo/semantics/openAccessinfo:eu-repo/semantics/articlehttps://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/14157