Antioxidant activities of phenolic compounds of Centaurea ensiformis P.H. Davis [Centaurea ensiformis P.H. Davis'in fenolik bileşiklerinin antioksidan aktiviteleri]

The aim of the present study was to investigate the antioxidant activities of 11 phenolic compounds previously isolated from an endemic Centaurea ensiformis P.H. Davis (Asteraceae) by 2,2-diphenyl-l-picryl-hydrazyl (DPPH) and ABTS decolorization assays. These compounds consisting of 2 phenolic glycosides (tacioside and protocatechuic acid), 2 acetophenon glycosides (picein and 4-hydroxyacetophenon 4-O-[6'-O-ß-D-apiofuranosyl]-ß-D-glucopyranoside), 1 coumarin glucoside (scopolin), 4 flavonoid glycosides (vicenin-2, schaftoside, neoschaftoside and chrysoeriol-7-O-mtinoside), 1 phenylpropanoid glycoside (sy-ringin) and 1 neolignan glucoside (dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside). Protocatechuic acid and tachioside had the highest activity (DPPH IC50: 6.47 and 22.87 mM; TEAC: 33.2±0.18 and 31.2±0.99, respectively) in both methods. Dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside also showed high activity compared to ascorbic acid in DPPH assay (IC50: 27.7 mM). Our results concluded that the C. ensiformis have a potential source of antioxidants of natural origin

Direct plant regeneration from different explants through micropropagation and determination of secondary metabolites in the critically endangered endemic Rhaponticoides mykalea

WOS: 000392625200004Direct plant regeneration from different explants, micropropagation and determination of secondary metabolites were studied in the critically endangered endemic Rhaponticoides mykalea (Hub.-Mor.) M.V. Agab & Greuter. Seed germination was achieved by damaging the seed coat and cultivating the embryos on Woody Plant Medium (WPM), of which 40% germinated. The epicotyls and cotyledonary petioles of seedlings were used as initial explants and direct shoot regeneration was obtained on WPM containing 2.22M 6-benzyladenine (BA). WPM medium supplemented with 2.22M BA and 4.92M indole-3-butyric acid (IBA) significantly improved the production of multiple shoots, resulting in an average of 5.6 shoots per explants. The highest rooting of shoots (35.6%) was observed with WPM medium containing 19.68M IBA with 990M putrescine. Plantlets with well-developed roots were transferred to soil and acclimatised within a plant growth chamber. Acclimatised plants showed 100% survival rate and remained healthy. As a part of our study, the content of secondary metabolites in three tissue culture regenerated lines were determined by HPLC analysis. Chlorogenic acid, Quercetin and scutellarin were confirmed secondary metabolites of R. mykalea

Secondary metabolites from Centaurea ensiformis P.H. Davis

Centaurea ensiformis P.H. Davis was evaluated for its secondary metabolites. 20 different compounds have been isolated and identified; four phenolic compounds, one aminoacid, two acetophenone glycosides, three phenylpropanoide glycosides, one coumarin glucoside, four flavon glycosides, two neolignan glycosides, two megastigmane glycosides and schikimic acid methyl ester. © 2010 Elsevier Ltd.SBAG 106S197This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) Research Project (SBAG 106S197). -

Secondary Metabolites of Centaurea cadmea Boiss.

WOS: 000319558500013Chlorogenic acid (1), scutellarin (2), syringin (3), 6S, 9R-roseoside (4) and beta-sitosterol-3-O-beta-D-glucopyranoside (5) were isolated from the aerial parts of Centaurea cadmea Boiss. (Asteraceae). Structure elucidation of the compounds were performed by using spectroscopic methods (1-D and 2-D NMR and LC-MS-MS). To the best of our knowledge, compounds 1, 2, 3 and 4 have been isolated for the first time from this endemic species. Compound 4 is new for the genus Centaurea.Ege UniversityEge University [11/ECZ/005]This study was supported by Ege University research project (11/ECZ/005)