Emine Dede, Nusret Genc, Mahfuz Elmastas, Huseyin Aksit and Ramazan Erenler* Pages 1 - 6 ( 6 )
Plant in Rhododendron genus that contains phenolic compounds has been used in traditional medicine and revealed considerable biological activities. Rhododendron ungernii Trautv. flowers were collected and dried in shade and 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 and all flavonoids displayed 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).
Rhododendron ungernii, antioxidant, active compound, flavonoids
Department of Chemistry, Faculty of Arts and Sciences, Tokat Gaziosmanpasa University, 60240 Tokat, Department of Chemistry, Faculty of Arts and Sciences, Tokat Gaziosmanpasa University, 60240 Tokat, Department of Biochemistry, Faculty of Pharmacy, University of Health Sciences, Istanbul, Department of Analitical Chemistry, Faculty of Pharmacy, Erzincan Binali Yildirim University, 24000 Erzincal, Department of Chemistry, Faculty of Arts and Sciences, Tokat Gaziosmanpasa University, 60240 Tokat