Zeynep Ulukanli

Chemical composition, antimicrobial, insecticidal, phytotoxic and antioxidant activities of Mediterranean Pinus brutia and Pinus pinea resin essential oils.

Essential oils of the resins of Pinus brutia and Pinus pinea were evaluated for their biological potential. Essential oils were characterized using GC-MS and GC/FID. in vitro antimicrobial, phytotoxic, antioxidant, and insecticidal activities were carried out using the direct contact and the fumigant assays, respectively. The chemical profile of the essential oils of the resins of P. pinea and P. brutia included mainly α-pinene (21.39% and 25.40%), β-pinene (9.68% and 9.69%), and caryophyllene (9.12% and 4.81%). The essential oils of P. pinea and P. brutia exerted notable antimicrobial activities on Micrococcus luteus and Bacillus subtilis, insecticidal activities on Ephestia kuehniella eggs, phytotoxic activities on Lactuca sativa, Lepidium sativum, and Portulaca oleracea, as well as antioxidant potential. Indications of the biological activities of the essential oils suggest their use in the formulation of ecofriendly and biocompatible pharmaceuticals.

Chemical Composition of the Essential Oil from Cupressus sempervirens L. horizontalis Resin in Conjunction with its Biological Assessment

Abstract Essential oil from the crude oleoresin of C. sempervirens L. was hydro-distillated and analysed by GC and GC-MS. The significant fraction of the essential oil constituted both monoterpene hydrocarbons (46.03 %) and oxygenated monoterpenes (17.27 %). The major components were mainly α-pinene (35.60 %), followed by trans-pinocarveol (5.22 %), α-phellandrene-8-ol (4.56 %), β-pinene (3.06 %), D-limonene (2.83 %), borneol (2.34 %) and camphene (2.15 %). Antibacterial assays indicated the moderate level effectiveness on all tested gram positive and negative bacteria. The most sensitive bacteria were Staphylococcus aureus (ATCC 29213) and Staphylococcus aureus (ATCC 95923) followed by Micrococcus luteus (NRLL B-4375). Insecticidal activity of the essential oil exposure (48 h) on Ephestia kuehniella eggs showed 20.83 % mortality at 100 μL L-1 air concentration. In the antioxidant assays, essential oil revealed a moderate level of the radical scavenging effect against DPPH and total phenolic content. Reducing power of the essential oil appeared to higher when compared to DPPH scavenging activity. Total phenolic content of the essential oil seemed to be well correlated with the assays of the DPPH and reducing power.

Essential Oil and Bioherbicidal Potential of the Aerial Parts of Nepeta nuda subsp. albiflora (Lamiaceae)

Abstract The secondary metabolites and their biobenefits of many species of the genus Nepeta have been assayed for determination of the chemical constituents. In this study, Nepeta nuda subsp. albiflora’essential oil was assayed and identified with gas chromatography/mass spectrometry (GC-MS). The oil has been principally dominated by 4aα,7α,7α,β-nepetalactone (74.27%) and 2(1H)-naphthalenone, octahydro-8a-methyl-trans-(10.09%). In the bioassay testings, direct exposure of the essential oil on five plant species (Triticum aestivum, Raphanus sativus, Lactuca sativa, Lepidium sativum and Portulaca oleracea) revealed significant herbicidal actions, inhibiting the germination, radicle and plumule elongation, fresh and dry weight. As a consequence, East Mediterranean Nepeta nuda subsp. albiflora with the essential oil bearing the crucial secondary metabolites could be suggested as a natural herbicide for further use in the agriculture.

Chemical Characterization, Phytotoxic, Antimicrobial and Insecticidal Activities of Vitex agnus-castus’ Essential Oil from East Mediterranean Region

Abstract Essential oil of Vitex agnus-castus’ leaves was analysed GC and GC-MS. The oil was predominantly rich in 1,8-cineole (24.38 %), sabinene (22.77 %), trans-β-farnesene (8.50 %), α-pinene (7.14 %), β-caryophyllene (6.49 %) and 1-terpinen-4-ol (5.23 %). In the phytotoxicity assay, the highest concentration of the oil (40 µL) completely inhibited the germinations of Lactuca sativa and Lepidium sativum. In the antimicrobial assays, essential oil was more active on yeast species and gram positive bacteria. The results of the insecticidal assays were also significant as the mortalities were 70 % and 96.67 % on Acanthoscelides obtectus and Tribolium castaneum at 34 µL L-1 and 136 µL L-1 oil (24 h), respectively. Essential oil of V. agnus-castus could be suggested as a potential source of bioagents for prokaryotic and eukaryotic organisms in concern.

Essential Oil Constituents of Tanacetum cilicicum: Antimicrobial and Phytotoxic Activities

Aerial parts of Tanacetum cilicicum were hydrodistillated for 3 h using Clevenger. Essential oil (EO) yield was 0.4% (v/w). According to the GC/MS analyses, EO of T. cilicicum consisted of monoterpenes [α-pinene (2.95 ± 0.19%), sabinene (2.32 ± 0.11%), and limonene (3.17 ± 0.25)], oxygenated monoterpenes [eucalyptol (5.08 ± 0.32%), camphor (3.53 ± 0.27%), linalool (7.01 ± 0.32%), α-terpineol (3.13 ± 0.23%), and borneol (4.21 ± 0.17%)], and sesquiterpenes [sesquisabinene hydrate (6.88 ± 0.41%), nerolidol (4.90 ± 0.33%), α-muurolol (4.57%  ± 0.35), spathulanol (2.98 ± 0.12%), juniper camphor (2.68 ± 0.19%), (-)-caryophyllene oxide (2.64 ± 0.19%), 8-hydroxylinalool (2.62 ± 0.15%), and -cadinene (2.48 ± 0.16%)]. In the antimicrobial assay, MIC/MBC values of the EO were the most significant on B. subtilis (0.39/0.78 µL/mL) and B. cereus (0.78/1.56 µL/mL). The most prominent phytotoxic activities of the EO were observed on L. sativa, L. sativum, and P. oleracea. The results of the present study indicated that EO of T. cilicicum includes various medicinally and industrially crucial phytoconstituents that could be in use for industrial applications. The finding of this study is the first report on this species from the East Mediterranean region.

Antimicrobial and Herbicidal Activities of the Essential Oil from the Mediterranean Thymus eigii

Abstract Essential oil (EO) of Thymus eigii (Lamiaceae) was hydrodistillated and characterized using with GC/MS. Forty-three constituents were determined accounting 100 % of the EO. The predominant constituents were thymol (24.77 %), carvacrol (14.00 %), p-cymene (10.91 %), γ-terpinene (6.53 %) and borneol (6.48 %). EO showed different levels of antimicrobial activities on test microorganisms. C. albicans, C. parapsilosis and S. aureus ATCC 29213 had the MIC/MFC/MBC values with 0.07/0.18 mg/ml, 0.18/0.36 mg/ml and 0.36/1.22 mg/ml respectively. EO of T. eigii exhibited pronounced herbicidal activities by inhibiting the germination and the growth of the seedlings of all plant species.

Secondary Metabolites and Bioactivities of Thymbra spicata var. spicata in Amanos Mountains

Abstract The essential oil of the aerial parts of Thymbra spicata var. spicata in Amanos Mountains was hydrodistillated and analyzed with GC-MS. Of the 15 compounds, the followings were the main constituents; carvacrol (57.95 %), γ-terpinene (18.95 %), p-cymene (9.43 %), and 1-phellandrene (3.26 %). A dose-dependent phytotoxic effect of the oil was found on Triticum aestivum, Zea mays, Lactuca sativa, Lepidium sativum and Portulaca oleracea. Antimicrobial results were also noteworthy on Bacillus subtilis ATCC 6663, Escherichia coli ATCC 25922, Candida parapsilosis ATCC 22019, Candida albicans ATCC 14053, Enterobacter hormaechei ATCC 700323, and Klebsiella pneumoniae ATCC 700603. Overall, T. spicata var. spicata in Amanos Mountains might be suggested as a potential and alternative bio-source for the development of biopesticide.