K. Hüsnü Can Başer

In vitro antioxidant properties and anthocyanin compositions of elderberry extracts

In this study, dried elderberry fruits growing wild in Turkey were macerated using different solvents and an infusion was prepared according to traditional methods. All extracts were investigated for their total phenolic content, total monomeric anthocyanins, qualitative-quantitative determination of cyanidin-3-glucoside (by HPLC-UV analysis), anthocyanin compositions (by LC/MS-MS), free radical scavenging activity (DPPH and ABTS) and inhibition of β-carotene/linoleic acid co-oxidation. An extract with 70% ethanol was found to be richer in cyanidin-3-glucoside when compared to the other extracts. The infusion was found to be as rich as the 70% ethanol extract. Ethanol and acetone extracts (both 70%) were found to be more active in the free radical activity and β-carotene bleaching assays. Water extract showed good ABTS radical scavenging activity when compared with ascorbic acid.

In vitro antioxidant properties and phenolic composition of Salvia halophila Hedge from Turkey

An endemic plant of Turkey Salvia halophila Hedge (Lamiaceae) was examined for its antioxidant activity and phenolic compositions. The aerial part of S. halophila was extracted with different solvents in an order of increasing polarity such as hexane, ethyl acetate, methanol, and 50% methanol using a Soxhlet apparatus. Water extract was also prepared from S. halophila by reflux. All solvent fractions were investigated for their total phenolic contents, flavonoids, flavonols, qualitative-quantitative compositions, iron(III) reductive activities, free radical scavenging activities and the effect upon linoleic acid peroxidation activities. The peroxidation level was also determined by the TBA method. The results of activity tests given as IC50 values were estimated from non-linear algorithm and compared with standards via BHT, ascorbic acid, gallic acid. Polar fractions were found more active among the others in free radical activity system whereas non-polar fractions protected the peroxidation of linoleic acid. Rosmarinic acid was the most abundant component, in the extracts.

Natural product studies of U.S. endangered plants: Volatile components of Lindera melissifolia (Lauraceae) repel mosquitoes and ticks

The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from Lindera melissifolia (Walt.) Blume (Lauraceae) (pondberry) drupes were gathered and analyzed by GC and GC-MS. The essential oil obtained from this endangered plant showed a significant dose dependent repellency of ticks and a moderate mosquito repellent effect while the subsequent hexanes extract was completely ineffective. Fractional freezing enriched the tick repellent components of the essential oil. Several known tick repellent components were recognized by the GC-MS comparison of the resulting fractions and β-caryophyllene, α-humulene, germacrene D and β-elemene warrant evaluations for tick repellency. Identifying pondberry as a potential renewable source for a broad spectrum repellent supports efforts to conserve similar U.S. endangered or threatened plant species.

Essential Oils of Echinophora lamondiana (Apiales: Umbelliferae): A Relationship Between Chemical Profile and Biting Deterrence and Larvicidal Activity Against Mosquitoes (Diptera: Culicidae)

ABSTRACT The essential oils from the flower, leaf, and stem of Echinophora lamondiana B.Yildiz et Z.Bahcecioglu were analyzed by gas chromatography—flame ionization detection and gas chromatography—mass spectrometry. In total, 41, 37, and 44 compounds were identified, which accounted for 98.0, 99.1, and 97.0% of flower, leaf, and stem essential oils, respectively. The monoterpenic hydrocarbons were found to be high in all samples of the essential oils. The major components of essential oils from flower, leaf, and stem of E. lamondiana were &dgr;-3-carene (61.9, 75.0, and 65.9%, respectively), &agr;-phellandrene (20.3, 14.1, and 12.8%, respectively), and terpinolene (2.7, 3.3, and 2.9%, respectively). Flower and leaf essential oils and terpinolene produced biting deterrence similar to 25 nmol/cm2 N, Ndiethyl-meta-toluamide (DEET; 97%) against Aedes aegypti (L.) and Anopheles quadrimaculatus Say. Compounds (+)-&dgr;-3-carene, (R)-(-)-&agr;-phellandrene, and water-distilled essential oils were significantly less repellent than DEET. Among essential oils, leaf oil was the least toxic of the oils, with an LC50 value of 138.3 ppm, whereas flower essential oil killed only 32% larvae, and no mortality of stem oil at highest tested dosages against Ae aegypti was observed. Terpinolene and &agr;-phellandrene showed higher toxicity than &dgr;-3-carene in both the species. In contrast to Ae. aegypti, all the essential oils showed toxicity in An. quadrimaculatus, and toxicity was higher in leaf oil than the other two oils. These results could be useful in finding new, safe, and more effective natural biopesticides and biting deterrent or repellents against Ae. aegypti.

Composition of the essential oils of Centaurea aphrodisea, C. polyclada, C. athoa, C. hyalolepis and C. iberica

Essential oils obtained by hydrodistillation from two endemic Centaurea species (C. aphrodisea Boiss. and C. polyclada DC.) and three widespread (C. athoa DC., C. hyalolepis Boiss. and C. iberica Trev. ex Sprengel) Centaurea L. (Asteraceae) taxa from Turkey were analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS) techniques. The analyses revealed 109 constituents, accounting between 87% and 93.4% of the oils. Hexadecanoic acid (8.1–27.9%) was the main constituent of C. iberica, C. hyalolepis and C. polyclada oils, while spathulenol (8.1%) was the major compound in C. aphrodisea and caryophyllene oxide (17.1%) in C. athoa oils.

Chemical Composition, Larvicidal, and Biting Deterrent Activity of Essential Oils of Two Subspecies of Tanacetum argenteum (Asterales: Asteraceae) and Individual Constituents Against Aedes aegypti (Diptera: Culicidae)

ABSTRACT Water-distilled essential oils from dried aerial parts of Tanacetum argenteum (Lam.) Willd. subsp. argenteum (Lam.) and T. argenteum (Lam.) Willd. subsp. canum (C. Koch) Grierson were analyzed by gas chromatography and gas chromatography-mass spectrometry. In total, 27 and 32 components were identified representing 97.2 and 98.7% of essential oils of subsp. argenteum and canum, respectively. Main compounds of T. argenteum subsp. argenteum were &agr;-pinene (67.9%) and &bgr;-pinene (4.8%), whereas &agr;-pinene (53.6%), 1, 8-cineole (14.8%), and camphor (4.7%) were the major constituents of subsp. canum. Essential oil of T. argenteum subsp. canum at 10 µg/cm2 with Biting Deterrent Index (BDI) value of 0.73 showed activity similar to N,N-Diethyl-meta-toluamide (DEET) at 25 mol/cm2, whereas the activity of essential oil of subsp. argenteum was lower (BDI = 0.47) than subsp. canum and DEET. Based on 95% CIs, activity of ß-caryophyllene (BDI value = 0.54) and caryophyllene oxide (BDI = 0.66) were significantly lower than DEET. In larval bioassays, essential oil of T. argenteum subsp. argenteum showed LC50 value of 93.34 ppm, whereas T. argenteum subsp. canum killed only 40% of the larvae at the highest dose of 125 ppm. Among the pure compounds, &bgr;-caryophyllene (LC50 = 26 ppm) was the most potent compound followed by caryophyllene oxide (LC50 = 29 ppm), which was also similar to (-)-&bgr;-pinene (LC50 = 35.9 ppm) against 1-d-old Ae. aegypti larvae at 24-h post treatment. Compounds (-)-&agr;-pinene and (+)-&bgr;-pinene showed similar larvicidal activity. Activity of (+)-&bgr;-pinene with LC50 value of was similar to the essential oil of T. argenteum subsp. argenteum.

Inhibition of Human Neutrophil Responses by the Essential Oil of Artemisia kotuchovii and Its Constituents

Essential oils were obtained by hydrodistillation of the flowers+leaves and stems of Artemisia kotuchovii Kupr. (AKEO(f+l) and AKEO(stm), respectively) and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The primary components of the oils were estragole, (E)- and (Z)-β-ocimenes, methyleugenol, limonene, spathulenol, β-pinene, myrcene, and (E)-methyl cinnamate. Seventy-four constituents were present at concentrations from 0.1 to 1.0%, and 34 compounds were identified in trace (<0.1%) amounts in one or both plant components. Screening of the essential oils for biological activity showed that AKEO(stm), but not AKEOf+l, inhibited N-formyl-Met-Leu-Phe (fMLF)-stimulated Ca(2+) flux and chemotaxis and phorbol-12-myristate-13-acetate (PMA)-induced reactive oxygen species (ROS) production in human neutrophils. Selected pure constituents, representing >96% of the AKEO(stm) composition, were also tested in human neutrophils and HL-60 cells transfected with N-formyl peptide receptor 1 (FPR1). One component, 6-methyl-3,5-heptadien-2-one (MHDO), inhibited fMLF- and interleukin 8 (IL-8)-stimulated Ca(2+) flux, fMLF-induced chemotaxis, and PMA-induced ROS production in human neutrophils. MHDO also inhibited fMLF-induced Ca(2+) flux in FPR1-HL60 cells. These results suggest that MHDO may be effective in modulating some innate immune responses, possibly by inhibition of neutrophil migration and ROS production.

Anticandidal Activity of the Essential Oil of Nepeta transcaucasicaGrossh.

Hydrodistallation of the aerial parts of Nepeta transcaucasica Grossh. (Lamiaceae), collected in Ağrı, Doğubayazıt Province, afforded an essential oil that was characterized by GC and GC/MS analyses. Twenty‐seven compounds, representing 97.69% of the total oil composition, were identified, and 4aα,7α,7aβ‐nepetalactone (1; 39%), 4aα,7α,7aα‐nepetalactone (2; 28%), and germacrene D (3; 15%) constituted the major components. The anticandidal effects of the oil were evaluated against seven Candida strains by using the broth microdilution method. The oil showed good inhibitory effects against C. glabrata and C. tropicalis at minimal inhibitory concentrations (MICs) of 0.09 and 0.375 mg/ml, respectively.

Volatile compounds from the aerial part and fruits of Grammosciadium pterocarpum Boiss. growing in Turkey

Volatile constituents obtained from crushed fruits and aerial parts of Grammosciadium pterocarpum Boiss. (Apiaceae) by microdistillation were analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS) systems, simultaneously. Fifteen components comprising 99.5% of the volatile oil of the fruit and twenty components comprising 97.4% of the volatile oil of the aerial parts were identified. The main constituents of the fruit volatiles were found to be linalool (68.4%) and β-pinene (22.0%), whereas caryophyllene oxide (55.1%) and β-caryophyllene (15.3%) were found to be major constituents in the volatiles of the aerial parts.

Essential Oil Composition of Tordylium elegans

The genus Tordylium L. (Umbelliferae) is represented by 16 species, including six endemic species in Turkey [1, 2]. Tordylium elegans (Boiss. & Balansa) Alava & Hub.-Mor. (Syn.: Ainsworthia elegans Boiss. & Balansa), the endemic species, grows in rocky places, fields, and roadsides as an annual plant 1 . There are only a few phytochemical and biological activity studies on some Tordylium species. Essential oil studies on Tordylium species are quite scarce [3–9]. Thus, in the present study, essential oils from crushed fruits of Tordylium elegans collected from different localities were distilled using an Eppendorf Microdistiller®. The oils were analyzed by GC-FID and GC/MS. The list of compounds identified in the microdistilled oils of Tordylium elegans with their relative percentages, retention indices, and percentage amounts of compound classes are given in Table 1. The aim of this study was to determine the essential oil composition of Tordylium elegans as a part of our ongoing research on Tordylium species. To date, the essential oils of T. apulum, T. pestalozzae, T. pustulosum, T. lanatum, T. trachycarpum, T. hasselquistiae, T. ketenoglui, T. syriacum, and Tordylium aegyptiacum growing in Turkey have been analyzed by our group, and their constituents have been determined [3, 7–9]. In this study, octyl hexanoate (72.8% in sample A and 93.1% in sample B) was found to be the main constituent of the samples collected from different places (Table 1). Therefore, this is the first report on the essential oil of T. elegans as an endemic species. Octanol and octyl esters appear to be the predominant components of the oils of Tordylium species. However, different environments may affect the amounts of the constituents in the essential oils. Plant Material. The plant materials were collected from two locations in Turkey. Dry fruits of Tordylium elegans were collected on June 22, 2007 from Adana-Pozanti-Gulek, Kesik Village (A), and on June 07, 2005 from Kahramanmaras, Ahir Mountain, Tomek Province (B). Voucher specimens are deposited at Duman s collection (MV & HD 9991 for A) and Duran s collection (AD 6950 for B). Isolation of the Essential Oils. Microdistillation (MD). Essential oils were extracted from crushed fruits of Tordylium elegans using an Eppendorf Microdistiller®. The crushed fruits were placed in a sample vial together with 10 mL of water. Sodium chloride (2 g) and water (0.5 mL) were placed in the collecting vial. n-Hexane (300 L) was added to the collecting vial to trap volatile compounds. The apparatus was operated according to the “Essential Oils Programme.” The sample vials were heated to 100 C at a rate of 20 C/min, kept at 100 C for 15 min, then heated to 112 C at a rate of 20 C/min and kept at 112 C for 35 min. Finally, the samples were subjected to a post-run for 2 min under the same conditions. The collecting vials, placed in a cooler, were kept at –1 C during distillation. After completion of the distillation, the organic layer in the collection vial was separated from the water phase and subjected to GC and GC/MS. GC and GC/MS. The oils were analyzed by capillary GC and GC/MS using an Agilent GC-MSD system (Agilent Technologies Inc., Santa Clara, CA).