Rafidain Journal of Science

A variety of 2-Amino-5-substituted -1,3,4-thiadiazoles (ATDA) were prepared by the reaction of thiosemicarbazide with different substituted carboxylic acids and phosphorous oxychloride as catalyst using conventional methods in comparison with the advantages of microwave techniques.
The 5-(substituted-1,3,4-thiadiazol-2-yl) carbamates derivatives were prepared by refluxing these (ATDA) with ethyl chloroformates using pyridine as a base to neutralize the acid produced which gave higher yield than sodium carbonate. The structures of the products were supported by IR spectroscopy.

A sensitive indirect spectrophotometric method is proposed for determining mefenamic acid in pure form and in its pharmaceutical preparations. The method is based on oxidation-reduction reaction between mefenamic acid and cerium (IV) ion, and subsequent Ce(III) reaction with arsenazo (III) reagent in acidic medium to produce a greenish-blue complex which is stable, water soluble and has a maximum absorption at 654 nm with a molar absorptivity of 1.731105 l.mol-1.cm-1. Beer’s law is obeyed in the concentration range from 1 to 10 g mefenamic acid in a final volume of 25 ml. The proposed method has been applied successfully to determine mefenamic acid in pharmaceutical preparations.

The study was conducted in Mosul-suburb to show the effects of smoking on antioxidants and some biochemical parameters which include: Vitamin E, Vitamin A, β-carotene, Vitamin C, Folic acid, Ceruloplasmin (Cp), Total protein, Albumin, Calcium, Total bilirubin, Direct bilirubin, Uric acid, Creatinine, Total iron binding capacity (TIBC), Iron, Sulfate, Glutathione(GSH), Malondialdehyde (MDA), Cholesterol, Glucose, Selenium and Transferrin saturation(%). The study included (102) persons living outside city center represented into two minor groups, smokers and non smokers.
The results showed that the level decreased significantly in rural smokers when compared with rural non smokers in: vitamin C, total bilirubin, direct bilirubin and MDA, and there was a significant increase in: vitamin A and Cp., but there wasn’t any significant changes in: total protein, albumin, uric acid, creatinine, TIBC, iron, sulfate, cholesterol, selenium, calcium, vitamin E, β-carotene, folic acid, GSH, glucose and transferrin saturation(%). Depending on the period of smoking, the results predicted that antioxidants and some other parameters (vitamin E, vitamin A, β-carotene, vitamin C, folic acid, total protein, albumin, calcium, total bilrubin, direct bilirubin and GSH) were decreased, while: Cp., uric acid, creatinine, TIBC, Iron, sulfate, MDA, cholesterol, glucose and selenium were increased with increased the period of smoking.

To eliminate the use of solvent during the course of reaction and to decrease the reaction time in addition to enhanced the yield in synthesis of some Mannich bases 5-((5-(Aryloxymethyl)-1,3,4-thiadiazol-2-ylamino)(phenyl)methyl)pyrimidine-2,4,6 (1H,3H,5H)-trione (2a-h),the reaction was carried out under microwave irradiation of equimolecular mixture of 2-amino-5-aryloxymethyl – 1,3,4 –thiadiazoles (1a-h), benzaldehyde and barbituric acid, using magnesium sulfate as absorption support.
In conventional method the attempts to react amine(1a)with aldehyde to form Schiff base and the reaction of this base with barbituric acid did not succeed.
The structures of these compounds were confirmed by IR Spectrophotometer. All these bases were screened for their antifungal activity against Aspergillus flavus and found to possess weak activity

An indirect spectrophotometric method is developed for the determination of benzocaine as pure and in pharmaceutical preparations. The method is based on the oxidation of benzocaine with iron (ΙΙΙ) in acidic medium, and the liberated iron (ΙΙ) reacts with 1,10 -phenanthroline to produce ferroin complex which has a maximum absorption at 510 nm against reagent blank. Beer’s law is valid over the concentration range of 5-80 µg benzocaine/25 ml and the molar absorptivity is 5.7 ×104 l.mol-1.cm-1, indicating high sensitivity. The common excipients and additives do not interfere in benzocaine determination. The proposed method is successfully applied to the assay of benzocaine in two synthetic preparations.

The study attempts to isolate the enzyme ceruloplasmin from human serum. Two proteinous components had been isolated by gel filtration chromatography from the precipitate produced by polyethylene glycol (4000). It was found that only the second peak had a high activity for ceruloplasmin. The apparent molecular weight of the isolated ceruloplasmin using gel filtration chromatography and SDS-PAGE was (138111) and (134400) dalton respectively.
Maximum activity for ceruloplasmin was obtained using (35.8) mmol/l of p-phenylenediamine as a substrate for the enzyme, sodium acetate (0.1 mol/l) as a buffer at pH (5.45) for (35) minutes at (56) C. Using lineweaver–burk plot, it was found that maximum velocity (Vmax) and Michaelis constant (Km) had the values of (0.83) µmol/ min and (15.38) mmol/l respectively. The effects of some chemical compounds on the ceruloplasmin activity were investigated. Sodium chloride showed uncompetitive inhibition on the activity of the enzyme at a concentration of (70) mmol/l.

This paper involves a spectrophotometric method for the determination of trace amounts of tetracycline in aqueous solution. The method is based on the coupling of tetracycline with diazotized p-nitroaniline reagent in basic medium to form a violet mono azo dye that is water – soluble, stable and shows maximum absorption at 569 nm. Beer’s law is obeyed over the concentration range 2 – 400 g / 25 ml final volume, i.e.,
(0.08 – 16) ppm with a molar absorptivity of 7.8  104 l.mol-1.cm-1 and sandell sensitivity index of 6.2  10-3 g cm-2. The method is applied to the determination of the compound in serum and urine by standard addition method in vitro and in vivo (serum and urine) and pharmaceutical preparation (tetracyclline’s ointment).

The new ligand -bis ( -thiolethysulphide) -1, 3, 4- oxadiazole-2yl) ethane (BTESOE) was prepared from the reaction of 1-, 2-- bis-( - chloro ethylsulphide)-1,3,4-oxadiazol-2yl) ethane with sodium sulphide in aqueous ethanol solution. The ligand was characterized using IR, UV/Vis, 1H-n.m.r, 13C-n.m.r, mass spectroscopies and molar conductivity. BTESOE was employed to synthesize four complexes with metals (M (II): Cu, Ni, Co and Hg), the complexes were studied using IR, UV/Vis, atomic spectroscopies, molar conductivity and magnetic susceptibilities techniques. The results showed that each of these complexes has an octahedral geometry structures.

A simple spectrophotoemtric method for the determination of mesalazine [5-aminosalicylic acid; (5-ASA)] in aqueous solution is achieved. The method is based on the reaction of mesalazine, with excess nitrite, in an acidic medium, to produce the corresponding diazonium salt. After the removal of residual nitrite with sulphamic acid, the diazonium salt is coupled with resorcinol reagent in basic medium to produce, an intense orange coloured water-soluble and stable azo-dye which exhibits maximum absorption at 471nm. Beer’s law is obeyed in the concentration range of 10-300µg of mesalazine in a final volume of 25 ml i.e., 0.4-12 ppm with a molar absorptivity of 2.9480×104 l.mol-1.cm-1 and Sandell sensitivity index of 0.0051µg.cm-2, a relative error of -0.96 to -0.23% and relative standard deviation of ±1.05 to ±0.37% depending on the concentration level. The proposed method has been applied successfully to determine mesalazine in pharmaceutical preparation (capsules).

Radon (222Rn ) concentration and Radium (226Ra ) content in some selected samples of Coffee powder of common use collected from the market, were estimated using solid state nuclear track detectors CR - 39 . The Radon gas concentration was found to vary from ( 36-108 )Bq.m-3. The effective Radium content of solid samples varies from ) 0.0185 - 0.0925) Bq.kg-1‌‌‌. The present investigation is useful from the health and environmental point of view.