In this study, a series of benzimidazole derivatives was synthesized by using a simple, inexpensive and rapid method using different ammonium salts. Some of these derivatives were exclusively isolated, characterized and tested for their anti-fungal activity. The biological activity of these compounds as fungicides was tested against three commercially known fungicides (C. albicans, C. glabrata and C. krusei). Most of the obtained compounds exhibit anti-fungal activity especially compounds VIB, VID and VIH which showed significant activity when compared with that obtained from standard drug.
The volatile components of the leaf oil of Baeckea frutescens L. (Myrtaceae) from the Hatinh Province, Vietnam, were analysed by capillary gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) and co-elution techniques. The identified compounds constituted more than 99.5% of the oil contents. Forty-nine compounds have been characterized among which a-humulene (19.2%), β-caryophyllene (17.3%), baeckeol (13.8%), a-thujene (8.8%), linalool (5.6%) and 1, 8-cineole (5.6%) were the major constituents. This result may represent another chemotype of the oil of B. frutescens.
Aims: Vietnam is a country blessed with many plants whose chemical compounds have not been previously examined. The aim of this research is to investigate the chemical constituents of essential oil of Baeckea frutescens.
Study Design: Extraction of essential oil from the air-dried leaf samples of B. frutescens and investigation of its chemical constituents.
Place and Duration of Study: Mature leaves of B. frutescens were collected from Hatinh Province, Vietnam in October 2013.
Methodology: Air-dried and pulverized leaves were subjected to hydrodistillation in accordance with Vietnamese Pharmacopoeia specification to obtained essential oil. The components of the oil were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) and co-elution techniques.
Results: Forty-nine compounds have been characterized among which a-humulene (19.2%), β-caryophyllene (17.3%), baeckeol (13.8%), a-thujene (8.8%), linalool (5.6%) and 1, 8-cineole (5.6%) were the major constituents.
Conclusion: The present oil compositions were found to be different from the results obtained previously from the essential oils of B. frutescens grown in other parts of the world. The present result may represent another chemotype of the oil of B. frutescens.
Aims: To establish a new analytical method for the extraction and pre-concentration of V (IV) and V (V) species in real samples by cloud point extraction (CPE) coupled with spectrophotometry using two newly laboratory-made chelating reagents.
Study Design: All factors affecting the extraction and determination of V (IV) and V (V) ions using micelle-mediation extraction were executed via a classical optimization. In addition the interferences study is also considered.
Place and Duration of Study: Department of Chemistry, College of Science for Women, University of Baghdad, Baghdad, Iraq in cooperation with Department of Chemistry, College of Science, University of Al-Qadisiya, Diwanya, Al-Qadisiya, Iraq between April 2014 and November 2014.
Methodology: The approach is based on sequential separation of two vanadium species in the same solution. First, the complexation of vanadium (IV) with 2-[(Benzo imidazolyl) azo]-4-benzyl phenol (BIABP) at pH 3.0 and then extracted into micelle phase. Second, the vanadium (V) remaining in aqueous phase after the separation of (IV) is complexed with 2-[2-(5-Nitro thiazolyl) azo]-8 hydroxyquinoline (5-NTA8HQ) and H2O2 in acidic medium to form a ternary complex (V(V)-H2O2-NTA8HQ) which being re-extracted into micelle phase of Triton X-114. The extracted complexes in cloud point layer are dissolved in a minimum amount of ethanolic 0.1 M HNO3, then V (IV) and V (V) are determined spectrophotometrically at their respective absorption maxima. The proposed method was applied to the estimation of the two vanadium species in various real samples with satisfactory results where the method detection limit in these matrices was of 0.120 and 0.037 µg g-1 for V (IV) and V (V) respectively.
Results: At established optimized conditions, a 159 and 99 fold enrichment factors and linear range of 10-100 and 1-70 ng mL-1, leading the limits of detection of 1.78 and 0.75 ng mL-1 for V (IV) and V (V) ions respectively to be achieved in aqueous solution. The average percent recovery of 98.3±0.7 and 97.6±0.4 and a precision (RSD%, n=8) of 0.67% and 0.46%, at 40 and 30 ng mL-1 for V (IV) and V (V) are obtained.
Conclusion: The described method is sensitive, easy to apply and interferences-free and in that way the determination of vanadium species in different samples was easily achieved. The results of the established method were compared statistically with ETA-AAS using t-paired test showing no significant difference at 95% confidence interval and the proposed method gave comparable analytical figures of merit compared with other sophisticated techniques.
This study is aimed to evaluate the effect of additives on cold flow properties of biodiesel fuel obtained from Azadirachta indica and Hevea brasiliensis, readily available seed oil in Nigeria. The seed oils were converted to biodiesels via transesterification and additives kerosene, Eva, Ethanol, Cristol and Lubrizol were added to evaluate the cold flow properties. The results showed that biodiesel produced from Azadirachta indica and Hevea brasiliensis has closed properties to diesel. Effects of ethanol, kerosene and commercial additive on cold flow behaviour of this biodiesel revealed that kerosene and EVA improve the cold ﬂow properties when blended up to 20%. Though, lower blends (2%) with cristol and Lubrizol 7671 shows better lowering of cold flow properties of biodiesels from Azadirachta indica and Hevea brasiliensis seed oils. This will lead to development of biodiesel as an alternative source of energy to diesel.
It is known that there are delicate links and fine parallels between an art and science. Both these spheres of human endeavor involve a unique combination of professional skill and creative search. Sometimes an intuitive line of a great poet or philosopher may be likened to the opening of a new horizon in science. Thus, the composer Maurice Ravel in his famous “Bolero” allegorically depicts the process of birth and development of an epochal discovery that gives rise to many advantages. At first, a musical tune arises whose sound is so weak, so feeble, that it can be easily drowned out by the surroundings. In the second movement, the music is repeated with the same melody, but now with an additional hue. The process repeats itself, again and again, until eventually the most powerful strains of bold, majestic music are then performed by the symphonic orchestra. Like that opening musical movement, the initial publications on the chemistry and application of a novel class of stable radicals, nitroxides, were first met with skepticism, and even strong criticism, from qualified and very professional members of the scientific community. But, later, more and more young enthusiasts joined the ranks of scientists applying this new tool in their research, and ever increasing reports of nitroxides were published in the various fields of chemistry, physics, biology, material science, and biomedicine. The theoretical and experimental data presented in this review clearly demonstrate both history and the current progress within the nitroxide “empire.