Seher Gur

Composition and Antimicrobial Activity of the Essential Oils of Tanacetum balsamita L. subsp. balsamita and T. chiliophyllum (Fisch. et Mey.) Schultz Bip. var. chiliophyllum (Asteraceae) from Turkey

Abstract The chemical composition of the essential oils of dried aerial parts of Tanacetum balsamita subsp. balsamita and T. chiliophyllum var. chiliophyllum were analyzed by GC and GC-MS. Forty five and forty six components were identified representing 81.0 % and 84.4 % of the oils, respectively. Trans-chrysanthenol (22.3 %), chrysanthenyl acetate (19.7 %), linalool oxide (11.5 %), camphor (7.5 %), 1,8-cineole (2.7 %) were found to be major components in T. balsamita subsp. balsamita and camphor (28.5 %), 1,8-cineole (17.1 %), camphene (7.1 %), isobornyl propionate (5.4 %), carveol (4.5 %) and borneol (3.5 %) were also found as major constituents in T. chiliophyllum var. chiliophyllum. In vitro antimicrobial activities of these oils and two antibiotics against Gram-positive and Gram-negative bacteria and two yeasts were also investigated. The results exhibited that the total oils and antibiotics possess moderate activities against all the tested microorganisms.

Design, synthesis, characterization and antibacterial and antifungal activity of a new 2-{(E)-[(4-aminophenyl)imino]-methyl}-4,6-dichlorophenol and its complexes with Co(II), Ni(II), Cu(II) and Zn(II): An experimental and DFT study

In this study, the complexes of Co (II), Ni (II), Cu (II) and Zn (II) with 2-(E)-(4-aminophenylimino)methyl-4,6-dichlorophenol were prepared and characterized by physical, spectral and analytical data. The metal: ligand stoichiometric ratio is 1:2 in all the complexes. The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Their structures were elucidated on the basis of elemental analysis, IR, 1H and 13C NMR spectra, UV-VIS, magnetic susceptibility measurements and thermogravimetric analyses. Both the antibacterial and antifungal activities and MIC values of compounds were reported. Among the tested compounds, the most effective compound providing a MIC value of 64 μg/mL is Zn(L)2 against C. tropicalis and B. subtilis. The theoretically optimized geometries of complexes have tetrahedral structures. The computed stretching frequencies of C=N, C-O and N-H bonds were found to be in good agreement with experimental data. All calculated frequencies fall within about 5% of the experimental frequency regions.

Some Biological Compounds, Antioxidant and Antimicrobial Activities of Endemic Hypericum uniglandulosum

We stadied some biologically active compounds, radical scavenging capacities, and antimicrobial activities in Hypericum uniglandulosum extracts. It was found that palmitic acid (12.16 ± 0.69%), oleic acid (3.45 ± 0.17%), and α-linolenic acid (17.15 ± 0.84%) were the dominant fatty acids in the extracts. It was concluded that the extracts contained stigmasterol (52.60 ± 0.57 μg/g), α-tocopherol (29.2 ± 0.54 μg/g), cholesterol (66.16 ± 0.78 μg/g), and as well as β-sitosterol (289.33 ± 4.96 μg/g). It was also determined that the methanol extracts were the most effective against free radicals. The results of the present study show the potent antimicrobial activity of H. uniglandulosum constituents suggesting that they deserve further consideration as novel antibacterial agents.

Chemical composition and biological activities of leaf and fruit essential oils from Eucalyptus camaldulensis

Abstract The chemical composition of the essential oils from the leaves and fruit of Eucalyptus camaldulensis grown in Mersin, Turkey was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The biological activities (antibacterial and antifungal) were examined using the agar well diffusion method. The main leaf oil constituents were p-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%). The main constituents of the fruit oil were eucalyptol (1,8-cineole) (34.5%), p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). Our results showed that both types of oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. The leaf and fruit essential oils of E. camaldulensis significantly inhibited the growth of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Streptococcus sp.) bacteria (p<0.05). The oils also showed fungicidal activity against Candida tropicalis and C. globrata. Leaf essential oils showed more activity than fruit essential oils, probably due to the higher p-cymene concentration in leaves.