Theoretical investigation of cyclooxygenase inhibition property of several non-steroidal anti-inflammatory drugs by density functional theory calculations and molecular docking studies

Understanding the geometry and electronic properties of non-steroidal anti-inflammatory drugs [NSAIDs] and the nature of their interactions with human cyclooxygenase-2 [COX-2] is important in the development and design of novel NSAIDs. In this paper, B3LYP/6-311++G [d,p] level of theory was applied to assess the acidity of NSAIDs in the gas phase. Subsequently, the role of intramolecular hydrogen bond on acidity of these compounds was confirmed by means of natural bond orbital [NBO] and quantum theory of atoms in molecules analyses [QTAIM]. Furthermore, by applying the polarized continuum model [PCM] at the B3LYP/6-311++G[d,p] level, the pK[a] value of NSAIDs in aqueous solution was calculated. The maximum error was found to be less than 0.1 pK[a] unit in comparison with the experimental value. This protocol can be used as a tool to predict pK[a] values of NSAIDs in future studies. In the last step, attempts have been made to generate a functional model of the structure of human COX-2 enzyme by means of homology modeling to gain more insight into the nature of interactions between NSAIDs and the active site of this COX-2 enzyme by docking studies. In addition, a mean binding energy for each drug was estimated based on its ionization ratio

Synthesis and biological evaluation of metronidazole derivatives as anti-giardia agents

Nitroimidazole derivatives such as Metronidazole [MTZ] have been used as anti- protozoa and anti-anaerobic bacteria. In this study several compounds of MTZ derivatives were synthesized and evaluated against Giardia lamblia cyst. Firs MTZ were reacted with several alkyl halide to obtain O-alkyl MTZ derivatives, then products were purified and their chemical structures were confirmed by elemental and spectral analysis [1HNMR and Mass]. In order to biological evaluation all compounds were investigated against 25 Giardia samples isolated from giarfdiasis patients. Results showed compound 2a had the most activity on cyst of Giardia in comparison with MTZ

Evaluation of radiochemical purities of some radiopharmaceuticals in Shiraz Namazi teaching hospital

Radiopharmaceuticals are a special group of drugs since many of them are eventually prepared in the hospital and the nuclear medicine department is therfore responsible for meeting quality criteria such as sterility, radionuclide, radiochemical and chemical purity. In this study radiochemical purity for more than 300 preparations of three different radiopharmaceutical formulations from commercial kits were tested using instant thin layer chromatography. The formulations namely 99mTc-DTPA, 99mTc-MDP and 99mTc-MIBI were obtained from Pars Isotope Co. Several paper chromatographic systems were used in this study. The result showed that the most observed impurities were hydrolyzed reduced 99m technetium. After the preliminary study we decided to change our imaging schedule in the nuclear medicine department and the sequence of imaging was changed. Cosequently, the results showed better radiochemical purities. Our equipments for detetion of radioactivity in paper chromatography were changed, for example the old dose calibrator was replaced by a gamma camera or a more accurate dose calibrator. Also, the thin layer chromatography systems were changed to those recommended by the factory and the new results showed much better radiochemical purities

Evaluation of radiolabeled streptokinase for thrombosis imaging

Cardiovascular disease is the major cause of morbidity and mortality in developing and developed countries. Rapid diagnosis of the thrombosis can be an essential step in management of the stroke. In this work a recently developed radiolabeled streptokinase [STP] tracer was evaluated in an animal thrombotic model using SPECT imaging and biodistribution studies. Locally labeled [67Ga]-Streptokinase was checked by ITLC, HPLC and SDS-PAGE experiments to check the tracer integrity and purity. The biodistribution studies were performed in thrombotic femoral vein of rats using tissue counting and preliminary SPECT studies, respectively [up to 2 h]. [67Ga]-Streptokinase prepared with suitable radiochemical purity [HPLC >95%, ITLC >99%] was administered to FeCl3 induced thrombotic rats and the percentage of injected dose per gram of tissue [ID/g%] as well as the SPECT images demonstrated the good specific binding of the tracer in thrombotic clots located in heart and aorta 2 hours post injection. [67Ga]-DTPA-STP can be a suitable probe for imaging of thrombosis in cardiovascular diseases. Ga-68 labeled STP has the potential to be an alternative superior labeled compound due to positron emission properties for PET studies as well as appropriate physical half life

Composition of the volatile oil of achillea wilhelmsii C. Koch from Iran

Composition of the volatile oil of the aerial parts of Achillea wilhelmsii C. Koch [Compositae] was investigated by GLC and GC-MS. Fifty-seven components representing 98.5% composition of the essential oil were characterized. The main components of the oil were carvacrol [25.1%], linalool [11.0%], 1,8-cineol [10.3%], E-nerolidol [9.0%] and borneol [6.4%]