Chemical composition and antimicrobial activity of the essential oils of Ferula latisecta and Mozaffariania insignis from Iran

The hydrodistilled oils from the aerial parts of Ferula latisecta and Mozaffariania insignis, which is endemic to Iran, were analyzed by GC and GC/MS. (Z)-Ocimenone (32.4%), (E)-ocimenone (20.3%), and cis-pinocarvone (11.4%) were the main components among the 22 constituents characterized in the oil of F. latisecta, representing 87.7% of the total components detected. Twenty-five compounds were identified in the oil of M. insignis, representing 99.0% of the total oil, with octyl acetate (41.1%), β-pinene (30.3%), and α-pinene (23.9%) as the main constituents. The essential oils were examined for their potential antimicrobial activities. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 561–563, November–December, 2006.     

Carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode for determination of dopamine in real samples

Room temperature 1-butyl-3-methylimidazolium tetraflouroborate ([BMIM][BF₄]) ionic liquid was employed for dispersion of multi walled carbon nanotubes (MWCNTs) and the formation of nanocomposite on the surface of a carbon-ceramic electrode. The surface of the modified electrode was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The modified electrode exhibited excellent electrochemical activity to oxidation of dopamine (DA); whereas electro oxidation of ascorbic acid (AA) was not seen and electro oxidation of uric acid (UA) appeared at a more positive potential than DA. The multi walled carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode was used for the selective determination of DA in the presence of high levels of AA and UA using differential pulse voltammetry. The calibration curve for DA was linear in the range of 3.00 to 130 µM with the detection limit (S/N=3) of 0.87 µM. The present electrode was successfully applied to the determination of DA in some commercial pharmaceutical samples and human blood serum.      

Effect of protonation on individual hydrogen bonds in the 8-oxoguanine-cytosine base pair: NMR,NBO and AIM analyses

Protonation increases the total binding energy of the 8-oxoguanine-cytosine (8OG:C) base pair by 60–70% at the B3LYP/6-311++G(d,?p) level of theory. It changes the individual H-bond energies, estimated from electron charge densities at bond critical points, by 1.16 to ?16.41?kcal?mol^?1. The individual H-bond energies and the two bond X–Y spin–spin coupling constants (^2hJ_X–Y) increase with protonation where 8OG behaves as an H-bond donor; the reverse is true for the H-bonds in which the 8OG unit acts as an H-bond acceptor. Similar to ^2hJ_X–Y, the value of ^1hJ_O–H (a one-bond H?···?Y spin–spin coupling constant) is distance dependent and in linear correlation with the O?···?H distance, but the ^1hJ_N–H values are independent of the N–H distance and the PSO term is the predominant portion in it. The ¹J_X–H spin–spin coupling constant is dominated by the negative FC term for all hydrogen bonds, although the PSO term is the best to investigate the behaviour of ¹J_X–H across the X–H?·?Y H-bond.     

Preparation of tin oxide (IV) nanoparticles by a green chemistry method and investigation of its role in the removal of organic dyes in water purification

Research on Chemical Intermediates - In this research, tin oxide nanoparticles (SnO2-nanoparticles) are synthesized using sol–gel method in polymeric bed and considering the principals of...     

Composition of the essential oils and antibacterial activities of Hymenocrater yazdianus, Stachys obtusicrena and Nepeta asterotricha three Labiatae herbs growing wild in Iran

Water-distilled essential oils from leaves of Hymenocrater yazdianus Rech.f., flowers of Stachys obtusicrena Boiss., and stems and flowers of Nepeta asterotricha Rech.f., which are endemic to Iran, were analyzed by GC and GC/MS. Fifty-five components of the leaf oil of H. yazdianus were characterized, representing 95.1% of the total components detected. The major constituents were identified as 1,8-cineole (17.6%), beta-caryophyllene (13.9%), alpha-pinene (10.6%) and caryophyllene oxide (10.4%). Germacrene-D (37.5%) and alpha-bisabolol (23.5%) were the main components among the twenty constituents characterized in the flower oil of S. obtusicrena, representing 90.8% of the total components detected. Thirty-five compounds representing 93.0% of the stem oil of N. asterotrica were identified among which terpinen-4-ol (22.8%) and gamma-terpinene (14.1%) were the major ones. The flower oil of the species was characterized by higher amounts of terpinen-4-ol (24.8%), 4a alpha, 7a beta-nepetalactone (18.2%) and 1,8-cineole (11.6%) among the thirty-three components comprising 98.5% of the total oil detected. The antibacterial activity of the stem, leaf and flower oils of Hymenocrater yazdianus, Stachys obtusicrena and Nepeta asterotricha against seven Gram-positive and Gram-negative bacteria were determined using the MIC method. The growth inhibitory zone (mm) was also measured.     

Biosynthesis of cerium oxide nanoparticles and its cytotoxicity survey against colon cancer cell line

Nanoparticles of cerium oxide (CeO₂-NPs), as a metal oxide of rare earth, have found an important role in improving technologies such as polishing, the degradation of harmful industrial dyes and even the treatment of some diseases. Therefore, the development of quick and inexpensive production methods for CeO₂-NPs is sought by researchers. In the present study, we report the biosynthesis of CeO₂-NPs using aqueous extract of Salvadora persica. Synthesized nanoparticles were investigated through powder X-ray diffraction (PXRD), ultraviolet–visible (UV–vis), Fourier transform infrared, transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray and Raman techniques. The UV–vis result shows an absorption peak at 325 nm, which confirms the formation of CeO₂-NPs. The band-gap of synthesized nanoparticles (4.1 eV) is higher than in its bulk state. PXRD and Raman show a crystalline fluorite cubic structure for synthesized nanoparticles. The morphology of synthesized nanoparticles shows a uniform and almost spherical shape via TEM and FESEM images. The particles size was estimated in the range of 10–15 nm. Cytotoxic activity of synthesized nanoparticles was determined through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against a colon (HT-29) cancer cell line. The results did not show any significant cytotoxic effect for synthesized samples even for concentration higher than 800 μg/mL. Hence, CeO₂-NPs were synthesized using a natural source; the procedure was rapid with good productivity and biosynthesized nanoparticles were non-toxic.     

Sums of series of Rogers dilogarithm functions

Some sums of series of Rogers dilogarithm functions are established by Abel’s functional equation.      

Chemical composition and antibacterial activity of essential oils from leaves, stems and flowers of Salvia reuterana Boiss. grown in Iran

The essential oils obtained by hydrodistillation of the leaves, stems and flowers of Salvia reuterana (Lamiaceae) were analysed by GC and GC/MS. Germacrene D and beta-caryophyllene were the major constituents in all the three oils: (28.5, 27.7 and 32.5%) and (15.5, 11.4 and 16.6%), respectively. Bicyclogermacrene (10.2 and 13.2%) was also prodominated in the stem and flower oils. The composition of the oils was mostly quantitativel rather than qualitatively different. All the oils consisted mainly of sesquiterpenes and a small percentage of non-terpenoid compounds. In all the three oils, monoterpenes were in a concentration less than 0.5%. Antibacterial activity was determined by the measurement of growth inhibitory zones.     

Fabrication of ferrocene functionalised ionic liquid/carbon nanotube nanocomposite modified carbon-ceramic electrode: application to the determination of hydrazine

A novel ionic liquid, 1-(ferrocenyl butyl)-3-methylimidazolium tetrafluoroborate (Fc-IL), was synthesised. The nanocomposite of Fc-IL and multi-walled carbon nanotubes (MWCNTs) was constructed and used for surface modification of carbon-ceramic electrode. The modified electrode was applied to the determination of hydrazine. Operational parameters such as pH of the solution, ionic liquid volume and amount of carbon nanotubes, which affect the analytical performance of the modified electrode, were optimised. The linear range of the modified electrode toward hydrazine concentration was 0.96–106.10 μg L^–1 with a detection limit of 0.64 μg L^–1 (S/N = 3). The modified electrode displayed high repeatability, reproducibility, long-term life time and low response time (<3 s). The applicability of this method was further tested by analysing the hydrazine content in boiler-feed water samples containing different concentrations of hydrazine and the results were in good agreement with the spectrophotometry method.