Synthesis and biodistribution of a novel 99mTc nitrido radiopharmaceutical with proline dithiocarbamate as a potential tumor imaging agent

In the present study, proline dithiocarbamate (PRODTC) ligand was radiolabeled with the [^99mTc≡N]²⁺ core successfully to obtain the ^99mTcN-PRODTC complex with high radiochemical purity. No decomposition of the complex at room temperature was observed over a period of 6 h. Its partition coefficient indicated that it was a hydrophilic complex. The electrophoresis results showed that the complex was negative. The biodistribution of ^99mTcN-PRODTC in mice bearing S 180 tumor showed that the complex accumulated in the tumor with a certain uptake. The tumor/blood and tumor/muscle ratios reached 2.19 and 4.54 at 2 h post-injection, suggesting it would be a promising candidate for tumor imaging.     

Influence of different 99mTc cores on the physicochemical and biodistribution behaviours of 99mTc-labelled complexes of pamidronate dithiocarbamate

Journal of Radioanalytical and Nuclear Chemistry - This study sought to evaluate the impact of 99mTcO and 99mTc≡N cores on the physicochemical and biodistribution properties of 99mTc-labelled...     

Synthesis and biodistribution of two novel 99mTc nitrido dithiocarbamate complexes containing heterocyclic linkage as potential brain perfusion imaging agents

Various plutonium compounds are handled in nuclear facilities of BARC. Hence, there is a possibility of occupational workers getting exposed to Pu. In vitro bioassay monitoring in which Pu is separated by chemical procedures from excreta samples and estimated by alpha-spectrometry, is the method of choice for the evaluation of internal dose to the occupational workers handling Pu. However, this method requires a suitable Pu tracer for reducing the uncertainties due to chemical yield in the separation, electro-deposition and counting efficiency. ²⁴²Pu is commonly used as a tracer but due to its non-availability, efforts were made earlier to indigenously synthesis ²³⁶Pu by proton irradiation of ²³⁷Np in BARC-TIFR pelletron facility. The present study, reports the feasibility of using ²³⁶Pu as a radiochemical yield monitor (tracer) in bioassay samples.     

Synthesis and biodistribution of a novel <Superscript>99m</Superscript>Tc nitrido dithiocarbamate complex containing ether group as a potential myocardial and brain imaging agent

In the present study, a novel ^99mTc nitrido dithiocarbamate complex containing ether group, the bis(2-ethoxyethyl dithiocarbamato) nitrido ^99mTc complex ^99mTcN(EOEDTC)₂ has been synthesized by the reduction of ^99mTcO₄ ⁻ into [^99mTcN]²⁺ with stannous chloride in the presence of succinic dihydrazide and propylenediamine tetraacetic acid, followed by the addition of the corresponding dithiocarbamate ligand. The radiochemical purity of the complex was over 90% as measured by thin layer chromatography (TLC). In vitro studies showed that the complex possessed good stability. Its partition coefficient indicated that it was lipophilic complex. The electrophoresis results showed the complex was neutral. Biodistribution in mice showed that the complex accumulated in the heart and brain with high initial uptake, suggesting the complex may lead to a further development of the radiopharmaceutical as a heart and brain perfusion tracer.     

Reactions of 3-nitro-2-trihalomethyl-2H-chromenes with C-nucleophiles. Synthesis of 3-nitro-4-(pyrazol-4-yl)-2-trihalomethylchromanes

The nucleophilic addition of acetylacetone and ethyl acetoacetate at the double bond of 3-nitro-2-trihalomethyl-2H-chromenes in the presence of NaH affords 2,3,4-trisubstituted chromanes containing the β-dicarbonyl fragment at position 4. The trans-trans configuration and the enol structure of the reaction products were confirmed by ¹H NMR spectroscopy and X-ray diffraction. Treatment of these compounds with hydrazine gives the corresponding 3-nitro-4-(pyrazol-4-yl)-2-trihalomethylchromanes. The reactions of 3-nitro-2-trihalomethyl-2H-chromenes with nitromethane and nitroethane in the presence of K₂CO₃ produce 1,3-dinitro derivatives of the chromane series. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1945–1955, November, 2006.     

Labeling of scorpion venom with 99mTc and its biodistribution

Labeling of scorpion venom (SV) was successfully achieved with ^99mTc using direct chelating method. Venom was labeled with ^99mTc using stannous chloride as reducing agent. Preliminary studies were done to establish the optimum conditions for obtaining the highest yield of the labeled venom. The labeling technique is effective, as a maximum labeling yield (97 %) was obtained after 30-min reaction time by using 80 μg SV in phosphate buffer of pH 7 and 25 μg Sncl₂·2H₂O at room temperature. Venom was injected into normal mice to determine the excretion pathway. Biodistribution studies in normal mice with SV shows rapid clearance of the venom from blood and tissue except for kidneys. The improvement of the immunotherapeutic treatment of envenomation requires a better knowledge of the biological actions of the SV since tissue distribution studies are very important for clinical purpose.     

Synthesis of 4-nitro-3,3,7-trimethyl-2-(2-hydroxystyryl)indolenines

The previously unknown hydroxystyrylindolenines have been synthesized by the direct condensation of 4-nitro-2,3,3,7-tetramethylindolenine with substituted salicylaldehydes. The structure of the prepared compounds has been confirmed by spectroscopic investigation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 340–342, March, 1990.     

Synthesis and crystal structure of polymeric thiocyanato-bridged copper(II) complex with 4-nitro-2-[(2-piperidin-1ylethylimino)methyl] phenolate

A polymeric thiocyanato-bridged Schiff base copper(II) complex [Cu(L)(NCS)] _n , where L is 4-nitro-2-[(2-piperidin-1-ylethylimino)methyl]phenolate, has been synthesized and structurally characterized by elemental analysis, infrared spectra, and single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁ with a = 8.527(5), b = 10.296(6), c = 9.697(6) Å, β = 103.77(2)°, V = 826.8(8) ų, Z = 2. In the complex, the Cu atom is in a square pyramidal coordination with one O and two N donor atoms of the Schiff base ligand and with one thiocyanate N atom, defining the basal plane, and with one symmetry related thiocyanate S atom occupying the apical position. The thiocyanate ligand links the Cu atoms through the end-to-end bridging mode.     

Synthesis of 4-(2-hydroxyaryl)-3-nitro-4H-chromenes

A combinatorial library of 4-(2-hydroxyaryl)-3-nitro-4H-chromenes was synthesized in high yield by C4-SMe substitution in N-alkyl/phenyl 4-(methylthio)-3-nitro-4H-chromen-2-amines with a variety of phenols. The reaction always provided C2 substitution in the phenol ring, dictated by hydrogen bond interactions between the phenolic hydroxyl group and the nitro group in 3-nitro-4H-chromenes. Reduction of the nitro group with concomitant hydrolysis of the enamine in 4-(2-hydroxyaryl)-3-nitro-4H-chromenes with Zn, Ac₂O in AcOH furnished hybrid amino-acid lactone incorporating ortho-tyrosine and phenyl alanine moieties.     

1-(4-硝基苯基)-3-(5-硝基-2-吡啶)-三氮烯的合成及其与汞(Ⅱ)的显色反应研究

合成了 1 -(4 -硝基苯基 ) -3 -(5-硝基 -2 -吡啶 ) -三氮烯 ,并研究了它与汞(Ⅱ )的显色反应。在TritonX -1 0 0的存在下 ,pH1 1 2的Na2 B4 O7-NaOH缓冲溶液中 ,试剂与汞生成 2∶1型桔黄色配合物 ,在 4 3 8nm和 52 5nm处分别有一正一负两个吸收波峰 ,用双峰双波长测定 ,其表观摩尔吸光系数为 2 1× 1 0 5L·mo1 1·cm 1,Hg2 +的浓度在 0～ 2 80 μg/L范围内符合比耳定律。成功地测定了人发和尿液中微量的汞。     

Synthesis of 99mTc(CO)3-NOET via [99mTc(OH2)3(CO)3]+ precursor and comparative biological studies with 99mTcN-noet

Summary The organometallic precursor fac-[^99mTc(CO)₃(H₂O)₃]⁺ was reacted with N-ethoxy, N-ethyl dithiocarbamate (NOET) in phosphate buffered saline (pH 7.4) at room temperature for 30 minutes to produce the ^99mTc(CO)₃-NOET complex. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography (TLC). No decomposition of the complex at room temperature (RT) was observed over a period of 6 hours. Its partition coefficient indicated that it was a lipophilic complex. The biodistribution comparison in mice of the ^99mTc(CO)₃-NOET complex and the ^99mTcN-NOET complex showed that the former had a lower heart and brain uptake as compared to that of the latter, suggesting the incorporation of the [^99mTc(CO)₃]⁺ core into the NOET ligand does not improve the biological features as a myocardial imaging agent.     

Labelling and quality control of gentamycin with99mTc and biodistribution

Gentamycin sulfate (antibiotic) was labelled with^99mTc with high radioactive yield. Technetium species were studied using different types of sephadex on columns. Stannous chloride was used as reducing agent for heptavalent^99mTc obtained directly from generator to lower oxidation state prior to labelling. Optimal pH was found to form the most stable complex. A lyophilized kit was prepared and it was stable for more than three months. Mice, rats and rabbits have been used as exprimental animals. Accumulation of more than 20% of the labelled formula in kidneys 30 minutes post injection in rats has been found. Gamma camera images in rabbit were clear enough for kidney delineation thirty minutes after injection.     

4-N-{2-[4-(2-巯基乙氧基)苯氧基]乙基}-1-N-对甲苯磺酰基哌嗪的合成

以对苄氧基苯酚为原料,经三步反应合成了2-[4-(2-溴乙氧基)苯氧基]乙醇(3); 3与1-对甲苯磺酰基哌嗪反应制得4-N-{2-[4-(2-羟乙氧基)苯氧基]乙基}-1-N-对甲苯磺酰基哌嗪(5);在5上引入乙酰巯基后再经碱性水解,合成了新化合物4-N-{2-[4-(2-巯基乙氧基)苯氧基]乙基}-1-N-对甲苯磺...     

Synthesis, radiolabeling and biodistribution studies of [99mTc(CO)3(MN-TZ-BPA)]+ in tumor-bearing mice

This study reports the synthesis, radiolabeling and preliminary biodistribution results of [^99mTc(CO)₃(MN-TZ-BPA)]⁺ in tumor-bearing mice. The novel nitroimidazole derivative was successfully synthesized by conjugation of bis(pyridin-2-ylmethyl)amine (BPA) to 2-methyl-5-niroimidazole via “click” reaction. The ligand could be labeled by [^99mTc(CO)₃]⁺ core in high yield to get [^99mTc(CO)₃(MN-TZ-BPA)]⁺, which was very hydrophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [^99mTc(CO)₃(MN-TZ-BPA)]⁺ accumulated in the tumor with certain initial uptake while poor retention. The rapid clearance from normal organs with favorable tumor/muscle ratios warrants further research to improve tumor targeting efficacy and pharmacokinetic profile of radiolabeled nitroimidazoles by structural modification.     

Labeling of famotidine with 99mTc and biodistribution studies on rats

Famotidine, a gastrointestinal drug was labeled with ^99mTc and its radiopharmaceutical potential was observed on male Albino Wistar rats. Labeling yield was over 95%. Average specific activity and n-octanol/water partition coefficient (lipophilicity) were approximately 74 MBq/mg-0.66 GBq/mg and 3.4, respectively. Biodistribution studies were performed on Albino Wistar rats. The activity per gram tissue was calculated and time-activity curves were generated. The majority of the activity was observed in stomach, small intestines and kidneys. Liver and kidneys showed lower uptake compared to other H₂-receptor rich tissues. Results show that ^99mTc-famotidine is H₂receptor specific. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and Structure of 1-Bromo-1-nitro-2-piperidino(cyclohexylamino)-2-phenylethenes

A preparation method was developed for new representatives of halonitroenamines, 1-bromo-1-nitro-2-piperidino(cyclohexylamino)-2-phenylethenes. Both molecules possess E configuration and are of high polarity.