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排序方式: 共有62条查询结果,搜索用时 15 毫秒
41.
Summary Lanreotide, a synthetic octapeptide analog of a native hormone somatostatin, was labeled with 131I, the most widely used therapeutic and easily available radionuclide. Radioiodination of Lanreotide was carried out by Chloramine-T
and Iodogen methods. Chloramine-T and Iodogen were used as oxidizing agents to form an electrophilic iodine species, which
then labeled the tyrosine of Lanreotide. The maximum radiolabeling yield was ~80%. Chloramine-T was found more suitable than
the Iodogen method, because nearly 25% of the initial iodine activity was lost/adsorbed on the Iodogen coating. Thin layer
and high performance liquid chromatographies were used for monitoring the reaction of 131I with Lanreotide, the stability and purity of 131I-Lanreotide. 相似文献
42.
Nasima Arshad Naghmana Rashid Sajida Absar Muhammad S. A. Abbasi Samreen Saleem Bushra Mirza 《Central European Journal of Chemistry》2013,11(12):2040-2047
Two flavonoids, karanjin (Kj) and karanjachromene (Kc) have been investigated spectrophotometrically for their mode of interactions with double stranded (ds)-DNA at blood (7.4) and stomach (4.7) pH and at human body temperature (37°C). Benesi-Hildebrand equation was used to evaluate the binding constants, K b . Binding constants at both pH values and at body temperature showed stronger binding of both the flavonoids and formation of 1:1 flavonoid-DNA complex via intercalative mode. However, K b values for karanjin were evaluated to be comparatively greater than karanjachromene at both pH values. The highest value of binding constant (1.32×105 M?1) for karanjin at blood pH (7.4) demonstrated its comparatively stronger binding and greater effectiveness at this pH. Standard Gibbs free energy changes (ΔG) of flavonoid-DNA complexes were calculated as negative values and indicative of spontaneity of their binding. Both flavonoids showed significant DNA protection activity. 相似文献
43.
In vitro Toxicological Study of Metal Oxides Nanoparticles on Oxidation of Succinate in Krebs Cycle and Their Resultant Effect in Metabolic Pathways
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Samreen Tanveer Muhammad Akhyar Farrukh Shaista Ali Muhammad Khaleeq‐ur‐Rahman Ayesha Imtiaz 《中国化学会会志》2014,61(5):525-532
In vitro study to evaluate toxic effects of metal oxides nanoparticles on energy producing cycle was conducted. In this study oxidation of sodium succinate in aqueous solution was investigated by using potassium ferricyanide as an oxidizing agent. Kinetic measurements were carried out on kinetic mode of spectrophotometer at λmax 420 nm. Effect of different metal oxides (MgO and CaO) nanoparticles was observed on the oxidation of succinate at 25 ± 0.5 °C. These metal oxides nanoparticles were prepared by hydrothermal method and their characterization were done by using FTIR, TGA, SEM‐EDX, TEM and XRD. Kinetic results indicated that these nanoparticles inhibit the conversion of succinate into fumerate. The inhibition is directly dependent on particle size of the nanoparticles and it was observed that particle size is inversely related to the oxidation rate of succinate. It was concluded at the end that elevated concentrations of metal oxides nanoparticles can severely affect the Krebs cycle by inhibiting succinate oxidation and lead to various metabolic disorders. 相似文献
44.
Choudhary MI Yousuf S Samreen Shah SA Ahmed S Atta-ur-Rahman 《Chemical & pharmaceutical bulletin》2006,54(7):927-930
The transformation of physalin H (1) with Rhizopus stolonifer and Cunninghamella elegans has afforded two new physalins, 6,7-dehydrophysalin H (2) and 6-deoxyphysalin H (3), along with a known isophysalin B (4). Their structures were elucidated by spectroscopic analysis. All of these compounds have shown potent leishmanicidal activity with IC50 values in the range of 6.03-13.80 microM. 相似文献
45.
Betson MS Clayden J Helliwell M Johnson P Lai LW Pink JH Stimson CC Vassiliou N Westlund N Yasin SA Youssef LH 《Organic & biomolecular chemistry》2006,4(3):424-443
Tertiary aromatic amides bearing stereogenic centres ortho to the amide group may adopt two diastereoisomeric conformations which interconvert slowly on the NMR timescale at ambient temperature, and are therefore detectable by NMR. Certain classes of stereogenic centre--particularly sulfoxides, ephedrine-derived oxazolidines, and proline-derived imidazolidines--strongly bias the population of the two conformers. We propose a model, supported by molecular mechanics calculations, which rationalises the sense and magnitude of the conformational selectivity attained in terms of the steric and electronic properties of the controlling centre. The control over conformation may be exploited either by trapping the favoured conformer as an atropisomer, or by using it to relay information about the stereochemistry of the controlling centre. 相似文献
46.
A new formulation of a freeze-dried kit for the labeling of tetrofosmin with technetium-99m has been developed. The kit contains
lyophilized mixture of 0.320 mg tetrofosmin [6,9-bis(2-ethoxyethyl)-3,12-dioxa-6,9-diphosphatetradecane], 0.025 mg stannous
chloride dihydrate, 5 mg sodium tartrate and 5 mg sodium hydrogen carbonate. The product contains no antimicrobial preservative.
When 99mTc pertechnetate up to 6 mL saline containing 200 mCi is added to lyophilized mixture, a lipophilic, cationic 99mTc complex is formed, 99mTc-tetrofosmin. The performance of newly developed kit is compared with commercially available MYOVIEW kit for heart imaging.
The patient studies show that the images of heart obtained by 99mTc-tetrofosmin prepared by new formulation are equally good to MYOVIEW. 相似文献
47.
A new 7-geranyloxycoumarin [7-(2,6-dihydroxy-7-methoxy-7-methyl-3-octaenyloxy) coumarin] named marmenol (1) has been isolated from the leaves of methanolic extract of Aegle marmelos belonging to the family Rutaceae. In addition to marmenol, several known compounds have also been obtained for the first time from the same source. They include: praealtin D, trans-cinnamic acid, valencic acid, 4-methoxy benzoic acid, betulinic acid, N-p-cis- and trans-coumaroyltyramine, montanine, and rutaretin. The structures of marmenol and known constituents were established with the help of NMR spectroscopy. However, structure of 1 was further confirmed via 2-D NMR experiments. 相似文献
48.
N. Amir S. Roohi S. Pervez A. Mushtaq M. Jehangir Y. Miyashita K. Okamoto 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):25-30
fac(S)-[Rh(aet)3] (aet = 2-aminoethanethiolate) is N3S3 metalloligand which can coordinate to transition metal ions to form S-bridge polynuclear complexes. The reaction was carried
out between 99mTcO4Na and fac(S)-[Rh(aet)3] in the presence of SnCl2·2H2O. A complex analogous to [Re{Rh(aet3)}2]3+ is formed.6 A simple method for radiolabeling of fac(S)-[Rh(aet)3] with 99mTc has been developed and radiolabeling efficiency was higher than 99%. Effect of SnCl2·2H2O concentration, electrophoresis, HPLC, UV-Visible absorption spectra and biodistribution studies in rats were performed.
Higher uptake by kidneys showed rapid distributions of the labeled fac(S)-[Rh(aet)3]. Liver uptake was significant, stomach, lungs and intestine uptake was high at 4 hours post injection time. 相似文献
49.
50.
Tariq Mahmood Babar Muhammad Moazzam Naseer Muhammad Khawar Rauf Humayun Pervez Masahiro Ebihara Nasim Hasan Rama 《中国化学快报》2014,25(9):1282-1286
A novel fused isocoumarin skeleton has been synthesized through selective domino multicyclizations by mixing homothallic acid and 2,3-diphenylacryloyl chloride at 200℃ under catalyst and solvent free reaction conditions. Six fused rings with two stereogenic centers were assembled in a convenient onepot operation in good yield. The resulting hexacyclic fused isocoumarin skeleton and its stereochemistry was fully characterized and unambiguously confirmed by X-ray diffraction analysis. 相似文献