Amount Of Stannous Chloride Research Articles

99mTc-Ibandronate as Imaging Radiopharmaceutical for Early Detection of Bone Diseases

Ibandronate was successfully labeled by using technetium-99m with maximum radiochemical yield (98.6%). The process is achieved by adding (25 µg) from stannous chloride in addition to (300 µg) of Ibandronate at room temperature in pH=7 for 15 min., we obtain a radiochemical yield (98.6%) and the radiolabeled complex was purified by high performance liquid chromatography (HPLC). The radiochemical yield was affected by many factors such as: Ibandronate amount, stannous chloride amount, reaction time, temperature of the reaction and pH of the reaction mixture. The in-vitro stability of 99mTc-Ibandronate was determined along (8 hours). The data obtained approve that 99mTc-Ibandronate complex was stable along (6 hours) without detection of any by-products in the reaction mixture.Biodistribution study showed high uptake and long retention of 99mTc-Ibandronate in bone was (44.32 % ID/organ) at (1 hour) post injection. Thus, 99mTc–Ibandronate could be used as a selective potential imaging agent for diagnosis of bone diseases

The Effect of Sn(II) Precursor on Morphology and Surface Area of as Synthesis SnO<sub>2</sub> Nanotube

Tin oxide nanotubes (STs) were synthesized by the hydrothermal process using manganese dioxide nanowires (MWs) as a template and followed by oxalic acid treatment. The effect of the stannous chloride concentration on the structure and crystallite size of the product were investigated. The phase composition was determined by XRD. Morphologies were revealed by FESEM and TEM. Firstly, manganese dioxide nanowires were fabricated from KMnO4. Then, tin oxide nanoparticles were coated on the wall surfaces of MWs templates. The template was then leached out by oxalic acid treatment. Nanotubular structure of the final product was formed by the agglomeration of the tin oxide nanoparticles coating on the template surfaces. On increasing the stannous chloride amount, crystallite size and the electrochemical properties increased, while the specific surface area decreased.

Rational design and synthesis of SnO2-encapsulated α-Fe2O3 nanocubes as a robust and stable photo-Fenton catalyst

In situ transformation of metal-organic frameworks (MOFs) is becoming a fascinating strategy to construct porous metal oxides with excellent performance in many fields. In this work, Prussian blue (PB) nanocubes are employed as the precursor of porous Fe2O3 to fabricate SnO2-encapsulated α-Fe2O3 (Fe2O3@SnO2) nanocubes by pre-coating Sn(OH)Cl on the surface of PB nanocubes. It is very interesting to find that SnO2 shells can not only preserve the microstructure of Fe2O3 nanocubes from high-temperature treatment, but also facilitate the phase variation from metastable γ/β-phase to stable α-phase. The thickness of SnO2 shells can be controlled by manipulating the amount of stannous chloride. When Fe2O3@SnO2 nanocubes are applied as heterogeneous photo-Fenton catalysts, they will exhibit much better catalytic efficiency for the degradation of Rhodamine B (RhB) than PB-derived Fe2O3 and commercial α-Fe2O3. The characterization results reveal that Fe2O3@SnO2 nanocubes have similar catalytic mechanism to conventional α-Fe2O3, and stable microstructure and preferable crystalline phase are primarily responsible for this significant enhancement. Some influential factors, including H2O2 concentration, catalyst dosage, pH value, and reaction temperature are investigated and analyzed in details. Moreover, Fe2O3@SnO2 nanocubes can maintain their catalytic efficiency during the repeated batch experiments. We believe Fe2O3@SnO2 nanocubes can be a new kind of high-performance green heterogeneous catalyst for the degradation of organic pollutants, and this study may provide a new idea to upgrade the performance of some conventional catalysts by rational design in the future.

Preclinical evaluation of 99m Tc-histidine as a possible tumor imaging agent

Radiolabeling of histidine (Hist), an essential amino acid, with 99mTc was performed. The radiochemical yield higher than 95% was achieved with stannous chloride as a reducing agent. Factors affecting the radiochemical yield (histidine amount, stannous chloride amount, reaction time, pH of the reaction mixture) were studied in detail, and the reaction conditions were optimized. In vitro stability of the radiolabeled complex was checked, and it was found to be stable for up to 6 h. 99mTc-Hist was injected intravenously into normal and tumor-bearing mice. Biodistribution studies revealed that the 99mTc-Hist uptake in tumor sites was 10 and 16% ID/g in ascites and 7 and 9.2% ID/g in thigh solid tumor at 60 and 120 min post injection, respectively. The amount of 99mTc-Hist in ascites and solid tumor increased with time and then decreased slowly. Thus, 99mTc-Hist can be used as a potential agent for imaging tumor sites.

Formulation and preclinical evaluation of 99mTc–gemcitabine as a novel radiopharmaceutical for solid tumor imaging

The aim of this study is the formulation of a new radiopharmaceutical for imaging solid tumor bearing. Gemcitabine is a nucleoside analogue used as chemotherapeutic agent. Gemcitabine was formulated and radiolabeled with one of the most important diagnostic radioactive isotopes (technetium-99m) to be investigated in solid tumor imaging. The labeling parameters such as gemcitabine amount, stannous chloride amount, pH of the reaction mixture, and reaction time were optimized. 99mTc–gemcitabine was prepared at pH 9 with a maximum labeling yield of 96 ± 0.3 % without any notable decomposition at room temperature over a period of 8 h. The preclinical evaluation and biodistribution in solid tumor bearing mice showed that 99mTc–gemcitabine had solid tumor selectivity, preclinical high biological accumulation in tumor cells and high retention. Tumor/normal muscle (T/NT) ratios increased with time showing high T/NT ratio (T/NT = 4.9 ± 0.27 at 120 min post injection) and high Tumor/Blood ratio (3.4 ± 0.06), suggesting 99mTc–gemcitabine as a novel solid tumor imaging agent.

99mTc-nebivolol as a novel heart imaging radiopharmaceutical for myocardial infarction assessment

Non-invasive quantification of myocardial β-receptors could become an independent prognostic marker for chronic heart failure and cardiovascular disorders. The aim of this study was to formulate a novel radiopharmaceutical for the detection of myocardial infarction at early stages in susceptible patients, which requires the development of high myocardium affinity radiopharmaceuticals able to establish an accurate in vivo quantification of cardiac β1-adrenoceptors. This was attained by the direct complexation of nebivolol as a cardioselective agent with technetium-99m as one of the most useful radionuclides in diagnostic nuclear medicine. Factors affecting the radiochemical yield such as nebivolol amount, stannous chloride amount, reaction time and pH of the reaction mixture were optimized. The results showed that the radiochemical yield was 95 ± 2.87 % and the radiolabeled compound was separated by high performance liquid chromatography. In vitro studies showed that the formed complex was stable for up to 24 h. In vivo uptake of 99mTc-nebivolol in the heart was 4.55 ± 0.23 % ID/g organ at 0.5 h post injection, whereas the clearance from Albino mice appeared to proceed via the hepatobiliary and renal clearance pathways. Predosing mice with cold nebivolol reduced the heart uptake to 1.1 ± 0.02 % and further confirmed the high specificity and selectivity of this radiotracer for the assessment of the myocardial β1-adrenoceptors.

Synthesis of 99mTc-oxybutynin for M3-receptor-mediated imaging of urinary bladder

Radiolabeling of oxybutynin, a muscarinic acetylcholine (mACh) receptor antagonist agent with 99mTc is of considerable interest for imaging of urinary bladder. This study is aimed to optimize radiolabeling yield of oxybutynin with 99mTc using SnCl2·2H2O as a reducing agent with respect to factors that affect the reaction conditions such as oxybutynin amount, stannous chloride amount, reaction time and pH of the reaction mixture. In vitro stability of the radiolabeled complex was checked and it was found to be stable for up to 8 h. 99mTc-oxybutynin was injected via subcutaneous and intravenous administration routes into normal Sprague–Dawley rats. Biodistribution studies have revealed that 99mTc-oxybutynin exhibits high affinity and specificity for the muscarinic M3 subtype located on the smooth muscle of urinary bladder relative to the M1 and M2 subtypes of the G protein coupled receptor (GPCR) superfamily. In vivo uptake of subcutaneous 99mTc-oxybutynin in urinary bladder was 19.6 ± 0.42% ID at 0.5 h, whereas in intravenous administration route the accumulation in the urinary bladder was found to be 9.4 ± 0.31% ID at 0.5 h post injection. Administration of cold oxybutynin effectively blocked urinary bladder uptake and further confirms the high specificity of this complex for the M3 receptor.

Labeling bombesin-like peptide with 99mTc via hydrazinonicotinamide: description of optimized radiolabeling conditions

Bombesin (BNN)-like peptides have very high binding affinity for the gastrin-releasing peptide (GRP) receptor. The goal of the current study was to optimize the labeling conditions of a new 99mTc-radiolabeled BNN-like peptide based on the bifunctional chelating ligand HYNIC using different co-ligands (EDDA and tricine). The radiolabeling conditions (pH, amount of co-ligand, amount of stannous chloride, temperature and reaction time) for newly-formed 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were optimized and evaluated by RHPLC and RTLC. Radiochemical yields for 99mTc-tricine-HYNIC-Q-Litorin and 99mTc-EDDA-HYNIC-Q-Litorin were 98.0 ± 1.7 and 97.5 ± 2.5%, respectively. When EDDA was used as co-ligand, the labeling of 99mTc-EDDA-HYNIC-Q-Litorin was optimal in the following reaction mixture: HYNIC-peptide: EDDA: 10 μg/5 mg, pH 3, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min. Besides, the optimum conditions were HYNIC-peptide:tricine: 10 μg/50 mg, pH 5, SnCl2 concentration: 12 μg/0.1 mL, reaction temperature: 100 °C, reaction time: 15 min for preparing 99mTc-tricine-HYNIC-Q-Litorin. The manufactured 99mTc-HYNIC-Q-Litorin conjugates may offer new possibilities for imaging cancer cells expressing bombesin receptors.

Preparation, quality control and stability of 99mTc-cefuroxime axetil

Cefuroxime axetil, a cephalosporin antibiotic used to treat bacterial infections, was investigated to label with 99mTc. Radiolabeling of cefuroxime axetil was carried out by using stannous chloride method. Effects of pH and stannous chloride amount on the radiolabeling yield were investigated. The radiochemical purity of 99mTc-cefuroxime axetil was determined by thin layer radio chromatography (TLRC), electrophoresis and high performance liquid chromatography. The maximum radiolabeling yield was 98±1%.

An Efficient Process for Synthesis of 2′-O-methyl and 3′-O-methyl Guanosine from 2-aminoadenosine Using Diazomethane and the Catalyst Stannous Chloride

An improved strategy for the selective synthesis of 2′-O-methyl and 3′-O-methyl guanosine from 2-aminoadenosine is reported by using the catalyst stannous chloride. The regioselectivity of the 2′ and 3′-O-alkylation was achieved by optimizing the addition, timing, and concentration of the catalysts and diazomethane during the methylation reaction. An efficient and selective alkylation at 2′-OH of 2-aminoadenosine was achieved by mixing a stoichiometric amount of stannous chloride at room temperature in DMF. The reaction mixture was stirred at 50°C for 1 min and immediately followed by addition of diazomethane. The resulting 2′-O-methyl 2-aminoadenosine was treated with the enzyme adenosine deaminase, which resulted in an efficient conversion to the desired 2′-O-methylguanosine (98% yield). The product was isolated by crystallization. In contrast, the methylation at 3′-OH of 2-aminoadenosine was achieved by mixing a stoichiometric amount of stannous chloride in DMF and stirring at 50°C for 15 min, followed by addition of diazomethane. The resulting mixture containing 3′-O-methyl-2-aminoadenosine in 90% yield and 2′-O-methyl-2-aminoadenosine in 10% yield was treated with the enzyme adenosine deaminase, which preferentially deaminated only 3′-O-methyl-2-aminoadenosine, resulting in the production of 3′-O-methylguanosine in 88% yield. Due to the extremely low solubility 3′-O-methylguanosine, the compound precipitated and was isolated by centrifugation. This synthetic route obviates the chromatographic purification. Selective monomethylation is achieved by using the unprotected ribonucleoside. As a result, the method described herein represents a significant improvement over the current synthetic approach by providing superior product yield and economy, a much more facile purification of 2′,3′-O-methylated isomers, and eliminating the need for protected ribonucleosides reagents.

Formation and extraction of Rh-Sn-Cl complexes with an alkylated 8-hydroxyquinoline

The work presented here focuses on the solution pretreatment and extraction stages of a solvent extraction system for rhodium from aqueous chloride solutions. The feed solution pretreatment stage involves a complexation reaction between the aqueous rhodium chloride complexes, [RhCl6-x(H2O)x](3-x)− and stannous chloride. Depending on the amount of stannous chloride used, at least two different Rh–Sn complexes are formed, either [Rh(SnCl3)5)]4− or [RhCl3(SnCl3)3]3−. Both of these respond well to extraction with Kelex 100, the extractant investigated in this work. The extraction stage was found to be quantitative for rhodium and it was also found to be very rapid, with contact times of less than 5 min sufficient for rhodium extraction. The extraction mechanism was determined to be ion-pair formation with the protonated Kelex 100 molecules at a stoichiometry such that the overall charge in the organic phase is neutral, i.e. three Kelex 100 molecules for [RhCl3(SnCl3)3]3− and four for [Rh(SnCl3)5]4−. © 1998 SCI

Development of a dextran kit for labelling with 99mTc and its evaluation for lymphoscintigraphy

A cold dextran (molecular weight 60,000–90,000) kit has been developed by a modified procedure to produce instant preparation of 99mTc-dextran suitable for lymphoscintigraphy. The preparation was subjected to various quality control measures. Effect of pH and amount of stannous chloride as a reducing agent on the labelling efficiency using ITLC were studied. The labelled complex was separated from both the reduced pertechnetate and pertechnetate and quantified. In a series of experiments hydrolysed/reduced 99mTc was found to be less than 3.0%, whereas pertechnetate was approx. 1.0%. Biokinetics of the agent in mice and blood clearance and rate of disappearance from the site of intradermal injection of the agent in rabbits were studied. The tagged agent for imaging of the lymphatic system activated by administering Freund's complete adjuvant (FCA)/ E. coli in rabbits exhibited its suitability for lymphoscintigraphy.

Titration of phytic acid

Titrimetric assays for phytic acid by titration with iron(III) or thorium are described. Stannous chloride interferes in both systems, causing negative errors directly proportional to the amount of stannous chloride. The thorium:phytate ratio in the complex formed is 2:1, which is interpreted as resulting from the possession of two chelating centres by phytic acid.

Partial Methylation with Diazomethane of the Sugar Moiety of Some C- and O-D-Glucopyranosides

On treatment of some C-and O-D-glucopyranosides with diazomethane in methanol or in methanol-dimethylformamide mixture, a partial methylation of the sugar moiety took place, though to a slight extent, to give a mixture of methyl ethers, in which 3-methyl ether is the major. The reaction is much favored in the presence of a small amount of stannous chloride. A O-α-D-glucopyranoside gave almost exclusively the corresponding 3-methyl ether of the glucose residue, while the β-anomer provided, beside 3-methyl ether, 2, 3-dimethyl ether nearly in equal amount. The benzylidene derivatives of O-α-and β-D-glucosides gave also the corresponding 3-methyl ether but 2, 3-dimethyl ether was formed only in trace and, instead, 2-methyl ether was provided.

Iron as a disturbing factor in the determination of phosphate by the molybdenum blue method

The interference of ferric and ferrous iron in the determination of phosphate by the molybdenum blue method has been studied. It was found that the presence of ferric iron in the solutions could cause either an increase or a decrease in the colour intensity depending on the amount of stannous chloride applied and on the acid and molybdate concentrations in the reagent. Also the phosphorus concentration exerted its effect upon the course of the errors. If the original modification of Truog and Meyer was employed, generally, the most convenient way for the elimination of the interference of ferric iron was to dilute the solution. An increase in the amount of stannous chloride largely helped to prevent the fading effect of ferric iron, provided the phosphorus concentration was not lower than 0.25 ppm. When the effect of ferric iron upon the development of molybdenum blue at various concentrations of sulphuric acid and ammonium molybdate was studied, the observation was made that at each acidity there could be found a concentration of molybdate in which the effect of even fairly high amounts of ferric iron was almost negligible. In lower molybdate concentrations the presence of ferric iron caused an increase in the colour intensity, in higher molybdate concentrations the fading effect of ferric iron was marked. This most suitable level of the molybdate concentration depended to a certain degree on the phosphorus concentration of the solution and on the amount of stannous chloride applied. Fairly good results could be obtained, if the ratio of molybdate (expressed as mg/ml) to acid (expressed as normality) in the solution to be reduced was five times as high as the acidity of the solution to be reduced (expressed as its normality), e.g. 4 in 0.8 N acid, 3.5 in 0.7 N acid, 3 in 0.6 N acid etc. Although it seemed to be fairly possible to avoid the interference of ferric iron by a proper choice of the concentrations of acid and molybdate and of the amount of stannous chloride applied, the fading effect of ferrous iron could not be prevented, if only sulphuric acid was used in the reagents. But the substitution of sulphuric acid by hydrochloric acid totally prevented the fading effect of ferrous iron. On the contrary, a slight increase in the colour intensity was demonstrated. This was true also when only one half of the acid present was hydrochloric acid. It was found that this mixture of sulphuric acid and hydrochloric acid in the molybdate reagent offers an available way for the elimination of the disturbing effect of iron.

GLASSES CONTAINING IRON OXIDE IX-b

This report is continued from the last report in which a metallic powder or reducing salt has been added to glass batches containing iron oxide and melted.(a) Glass melted by adding aluminium powder to a base glass batch in such proportions as 0.1, 0.5, 1.0%.(b) Glass melted by adding aluminium powder to a base glass batch in which 1% of lime has been replaced by iron oxide, in such proportions as 0.1, 0.5, and 1.0%.The transmission curves of these glasses have been measured. The shortest wave length that transmits them is in general reduced as the amount of aluminium powder added is increased, and the colour of the glass becomes greyish, accordingly a total transmission becomes smaller.(c) Glass melted by adding to a base glass batch some stannous chloride in such proportions as 1, 4 and 8%.(d) Glass melted by adding stannous chloride to a bese glass in which 1% of lime has been replaced by iron oxide, in such proportions as 1, 2, 4, 6 and 8%.The transmission curves of these glasses have been measured. It has been found that the limit of wave length that transmits these glasses tends to shift toward short wave length as the amount of stannous chloride added increases, while the wave length that shows a maximum transmission tends to shift toward the blue in spectrum. These transmission curves intersect somewhere between 480 and 520.As a result of this study it is found that the color of the glasses will be yellowish as the amount of zinc, magnesium added is increased. This seems to be that it must have reduced to colloidal iron rather than ferrous oxide. Aluminium turns to greyish while stannous chloride becomes bluish which is the color presented by ferrous oxide. In either case the amount of ferrous oxide is increased and that of ferric oxide is reduced in the glass.