Yavuz Bagci

Volatile constituents of two endemic Centaurea species from Turkey: C. pseudoscabiosa subsp. pseudoscabiosa and C. hadimensis

The essential oils obtained from two endemic Centaurea species (Compositae) from Turkey, C. pseudoscabiosa subsp. pseudoscabiosa Boiss. et Buhse (Sect. Acrocentron) and C. hadimensis Wagenitz, K. Ertugrul et H. Dural (Sect. Psephelloideae), have been studied. Germacrene D was the major component (36.0 and 44.3%, respectively), followed by β-caryophyllene, bicyclogermacrene and β-sesquiphellandrene.

Determination of antioxidant effects of some plant species wild growing in Turkey

In this study, the antioxidant activity of 50% aqueous methanol extracts of Crataegus tanacetifolia (Lam.) Pers, Crataegus bornmuelleri Zaberi, Crataegus orientalis Pall. ex M.Bieb. var. orientalis, Crataegus szovitsii Pojark, Crataegus curvisepala Lindm., Crataegus monogyna Jacq. subsp. monogyna, Crataegus monogyna Jacq.subsp. azarella (Gris.) Franco, Crataegus micophylla C.Koch, Rosa foetida Herrm., Rosa hemisphaerica J.Herrm., Rosa pulverulenta M.Bieb., Rosa canina L., Rubus discolor Weihe & Nees, Rubus canescens DC. var. canescens, Rubus sanctus Screber, Rubus caesius L., Sorbus umbellata (Desf.) Fritsch var. umbellata, Prunus avium L. (Moench.) and Prunus cerasus L. Mespilus germenica was evaluated by various antioxidant assays, including free radical scavenging, hydrogen peroxide scavenging and metal-chelating activities. The extracts of R. hemisphaerica J.Herrm., P. cerasus L. and R. canina L. showed more stronger free radical scavenging and hydrogen peroxide scavenging activities, and the extracts of R. foetida Herrm. (62.54%) and P. cerasus L. showed stronger metal-chelating activity. The results obtained in the present study indicated that the R. hemisphaerica J.Herrm., P. cerasus L. and R. canina are potential sources of natural antioxidant. These antioxidant properties depend on the concentration of the sample.

ESSENTIAL OIL COMPOSITION OF TWO ENDEMIC CENTAUREA SPECIES FROM TURKEY CENTAUREA MUCRONIFERA AND CENTAUREA CHRYSANTHA COLLECTED IN THE SAME HABITAT

The essential oils of two endemic Centaurea species from Turkey, C. mucronifera and C. chrysantha, collected in the same habitat, have been studied. The main compounds of the former were germacrene D (29.3%), β-eudesmol (17.4%) and β-caryophyllene (7.3%), while in the latter germacrene D (27.4%), caryophyllene oxide (9.5%) and bicyclogermacrene (5.4%) were detected among its major constituents. The two species produced many similar compounds in their essential oils that could be justified by the similar ecological conditions of their habitat, but also many differences were found that could confirm their taxonomic separation.

Flavonoid glycosides from Centaurea pseudoscabiosa subsp. pseudoscabiosa from Turkey

Three flavonoid glycosides were isolated and characterized, together with a further 13 substances belonging to various classes of compounds, in particular two phenolic acids, a coumarin, a sugar and nine flavonoids from the flowered aerial parts of Centaurea pseudoscabiosa subsp. pseudoscabiosa Boiss. et Buhse (Asteraceae). Some considerations about their evolutionary meaning are provided.

Antioxidant properties of 12 cornelian cherry fruit types (Cornus mas L.) selected from Turkey

+2 ) chelating activities. The methanolic fruit etxracts of the Cornus mas L. fruit types (H 2O2 and diphenylpicrylhydrazyl (DPPH) scavenging activities, Fe +2 chelating activity) examined in the assay showed the strongest activities. The highest antiradical activity was found 44-05 type (0.943) followed by 44-04 (0.860), 77-09 (0.810) and 77-05 (0.723) types respectively. The lowest value was found 44-01 (0.537), 77-06 (0.580), 77-11 (0.567) and 77-02 (0.563) types. The highest chelating activity was found; 44- 05 (54.213%), 44-04 (49.890%), 77-09 (47.287%) and 77-05 (45.180%) cornelian cherry type respectively. The lowest cheting activity was found 77-06 (33.883%), 44-01 (34.106%) and 77-11 (34.510%) types. In terms of H 2O2 inhibition, the highest rate was obtained from 44-05 (79.103%), the lowest one was 44-01 type to be 37.720%.

A multivariate statistical approach to Centaurea classification using essential oil composition data of some species from Turkey

The composition of the essential oils of ten Centaurea species from Turkey, Centaurea aladaghensis, C. antiochia var. prealta, C. antitauri, C. babylonica, C. balsamita, C. cheirolepidoides, C. deflexa, C. iconiensis, C. lanigera, C. ptosimopappoides have been studied. Multivariate statistical analyses (Principal Component Analysis, Multidimensional Scaling, Hierarchical Cluster Analysis) applied to GC-MS data, seem to be very useful to investigate and establish the natural taxonomic delimitation of this very difficult genus. The groupings resulted independent from the ecological similarities (i.e. plants that live in the same habitats or share similar morphological characteristics), so it seems that the environment has no influence on the biosynthesis of the volatiles of these plants.

Chemical Composition of the Essential Oil of Prangos uechtritzii Boiss. et Hausskn. Fruits from Turkey

Abstract The chemical composition of a hydrodistilled essential oil of Prangos uechtritzii Boiss. et Hausskn. growing wild in Turkey was examined by GC/MS. Thirty-eight constituents were identified. p-Cymene (10.9%), γ-terpinene (7.0%), β-phellandrene (7.8%), α-phellandrene (6.3%) and (Z)-β-ocimene (4.6%) were found to be the major constituents of the oil.

Determination of mineral contents of bee honeys produced in Middle Anatolia.

The mineral contents of 43 honey samples from the middle regions of Turkey were investigated. Minerals were determined by inductively coupled plasma-atomic emission spectrophotometry. Calcium, potassium, sodium and phosphorus were the most abundant of the elements in all samples with average concentrations ranging between 40.13 and 189.69 mg/kg for calcium, 161.01 and 598.62 mg/kg for potassium, 9.34 and 45.9 mg/kg for sodium, and 460.11 and 3,776.96 mg/kg for phosphorus. Cluster analysis of the honeys’ data revealed that mineral contents of Çorum and Konya honeys were closer as they formed a cluster at a similarity level of 60%.

Prenylated polyphenolic compounds from Glycyrrhiza iconica and their antimicrobial and antioxidant activities.

A new prenylated isoflavan, iconisoflavan (1), and a new prenylated isoflav-3-ene, iconisoflaven (2) were isolated from the roots of Glycyrrhiza iconica together with four known ones namely (3S)-licoricidin (3), licorisoflavan A (4), topazolin (5) and glycycoumarin (6). The structures were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as well as HR-MS. Furthermore, the absolute configurations of compounds 1, 3 and 4 were established by electronic circular dichroism (ECD). All the isolated compounds (1-6) were evaluated for their in vitro antimicrobial activities against five pathogenic bacteria and one yeast (Candida albicans) using an in vitro microdilution method. Compounds 1 and 3-5 displayed significant activity against Salmonella typhimurium ATCC 13311 with MIC values ranging from 2 to 8 μg/mL. Additionally, all compounds were screened for their in vitro free radical scavenging activities using an in vitro microdilution DPPH assay spectrofotometrically. The tested compounds exhibited IC50 values in the range of 0.18-0.56 mg/mL, suggesting an activity comparable with that of ascorbic acid (IC50: 0.07 mg/mL). To the best of our knowledge, the present study constitutes the first phytochemical and bioactivity investigation on G. iconica.

Linum ertugrulii (Linaceae), a New Species from Central Anatolia, Turkey

Linum ertugrulii O. Tugay, Y. Bağci & Uysal sp. nova (Linaceae) from Cihanbeyli (B4 Konya, Turkey) is described and illustrated. It is closely similar to L. flavum, L. pamphylicum and L. ciliatum, from which it differs mainly in having a stoloniferous stem, and in the leaf and floral features. Notes are presented on its habitat ecology and biogeography.