Rapid Preparation and Easy Quality Control Procedures for 99mTc‐Tin‐Nano Colloid: A Lymphoscintigraphic Agent

^99mTc‐Tin‐nano colloid is a radiopharmaceutical that can be useful in evaluation of the patients with breast cancer. The current method for preparation requires a lengthy boiling water bath procedure, and the recommended quality control procedure is cumbersome and time consuming. Using a microwave oven, the heating time necessary to provide a maximum labeling efficiency has been reduced to 10 second. A new mini paper chromatography (MPC) system has been developed to analyze the radiochemical purity (RCP) of the labeled preparation involving two different developing solvents. The recommended thin layer chromatography (TLC) system involving the use of an Al₂O₃ coated plate requires an average time for drying and development of 34.5 ± 0.44 min (n = 30) to complete, whereas the new MPC system has an average developing time of 2.1 ± 0.2 min (n = 20). For RCP values the MPC and TLC methods are correlated closely (r = 0.94). The combined use of the microwave oven heating method and over quick quality control system will facilitate the rapid emergency use of ^99mTc‐Tin‐nano colloid.     

Radiocomplexation and biological characterization of the <Superscript>99m</Superscript>TcN-trovafloxacin dithiocarbamate: a novel methicillin-resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> infection imaging agent

Extraction of europium(III) from nitric acid medium by a solution of tri-n-butylphosphate (TBP) and n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in the room temperature ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (amimNTf₂ where a = butyl or hexyl or octyl), was studied. The distribution ratio of ^(152+154)Eu(III) in TBP-CMPO/bmimNTf₂ was measured as a function of various parameters such as the concentrations of nitric acid, CMPO and NaNO₃. Remarkably large distribution ratios were observed for the extraction of europium(III) when bmimNTf₂ acted as diluent. The stoichiometry of metal-solvate in organic phase was determined by the slope analysis of extraction data.     

Radiosynthesis and biological evolution of <Superscript>99m</Superscript>Tc(CO)<Subscript>3</Subscript>–sitafloxacin dithiocarbamate complex: a promising <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> infection radiotracer

Garenoxacin (GXN) was modified to its dithiocarbamate followed by radiolabeling with technetium-99m (^99mTc) through [^99mTc-N]²⁺ core. The suitability of the ^99mTcN–Garenoxacin dithiocarbamate (GXND) complex as a potential multiresistant Staphylococcus aureus (MDRSA) and penicillin-resistant Streptococci (PRSC) infection radiotracer was assessed in artificially infected rats (AFRT). The radiolabeled complex was investigated for its radiochemical purity (RCP), permanence in serum using HPLC and TLC methods. In vitro binding with MDRSA and PRSC was performed at 37 °C. The ^99mTcN–GXND showed maximum RCP of 98.00 ± 0.22% and remained more than 90% stable up to 4 h. The ^99mTcN–GXND showed saturated in vitro binding with living MDRSA and PRSC, respectively. The complex showed normal biodistribution in healthy rats (HRT), however in AFRT, seven fold uptakes was observed in infected muscle as compared to inflamed and normal muscles. Based on the high RCP, stability in serum, better in vitro binding with bacteria, biodistribution behavior and the target to non-target (infected to inflamed muscle) ratio, we recommend the ^99mTcN–GXND complex for in vivo investigation of MDRSA and PRSC infection in human.     

Radiocharacterization of the 99mTc�Crufloxacin complex and biological evaluation in Staphylococcus aureus infected rat model

^99mTc?Crufloxacin (^99mTc?CRUN) complex was prepared by reaction of different amounts of reduced sodium pertechnetate with different amount of Rufloxacin (RUN) antibiotic for the in vivo scintigraphic localization of the Staphylococcus aureus (S. aureus) infectious foci in Male Wister Rats (MWR) model. The ^99mTc?CRUN complex was radiochemically and biologically characterized in terms of radiochemical stability in saline, serum, in vitro binding with S. aureus and biodistribution in artificially infected with S. aureus MWR. The ^99mTc?CRUN complex showed stability more than 90% up to 240 min in normal saline with a maximum stability value of 98.10 ± 0.18% at 30 min after reconstitution. At 37 °C the complex showed in vitro permanence in serum up to 16 h with 13.90% side products during incubation. The ^99mTc?CRUN complex showed saturated in vitro binding with S. aureus at different intervals with a maximum uptake value of 71.50%. Infected to normal muscle, infected to inflamed and inflamed to normal muscles ratios were approximately 6.04, 4.31 and 1.40. Based on the stability of the complex in saline, serum, in vitro binding with S. aureus and biodistribution results, the ^99mTc?CRUN complex is recommended for in vivo scintigraphic localization of the S. aureus in vivo infectious foci in human.     

Assessment of multifragmentation under the effect of symmetry energy

We study the effect of symmetry energy on the fragment production for the reactions ₂₀ ¹⁰ Ne₁₀+ ₂₀ ¹⁰ Ne₁₀ and ₁₉₇ ⁷⁹ Au₁₁₈ + ₁₉₇ ⁷⁹ Au₁₁₈ for the incident energy range of 50–1000 MeV/nucleon using isospin-dependent quantum molecular dynamics (IQMD) model. Our study shows that the density-dependent symmetry energy plays a significant role in multiplicity of fragments produced at low energy. Moreover, sensitivity of density-dependent symmetry energy decreases with increase in neutron content of colliding system. We also compare the symmetry energy suggested by different groups. A comparative study of experimental results with theoretical calculations of IQMD shows that the density-dependent symmetry energy is a good probe to explain the multiplicity of the fragments at low energy.     

Substantially enhancing the catalytic performance of bis(imino)pyridylcobaltous chloride pre‐catalysts adorned with benzhydryl and nitro groups for ethylene polymerization

Variations in the ligand structure of homogeneous late transition metal catalysts through judicious choice and location of substituent is the foremost strategy in improving their catalytic performance for ethylene polymerization. In this contribution, symmetrical and unsymmetrical bis(imino)pyridylcobaltous chloride complexes adorned with nitro and benzhydryl groups {2‐[1‐(2,6‐dibenzhydryl‐4‐nitrophenylimino)ethyl]‐6‐[1‐(alkylphenylimino)ethyl]pyridylcobaltous chloride (alkyl: R¹ = Me and R² = H, Co1 ; R¹ = Et and R² = H, Co2 ; R¹ = ⁱPr and R² = H, Co3 ; R¹ and R² = Me, Co4 ; R¹ = Et and R² = Me, Co5 ; R¹ = benzhydryl and R² = NO₂, Co6 )} have been prepared and applied as catalysts for ethylene polymerization. The molecular structure of Co1 and Co2 revealed the unequal steric protection of the cobalt center induced by bis(imino)pyridine chelate. In the presence of methylaluminoxane (MAO) or modified methylaluminoxane (MMAO) activators at different ethylene feeding rates (1 and 10 atm), catalysts Co1 – Co5 displayed high activities at 10 atm ethylene and produced strictly linear polyethylene (PE) with high molecular weight, Co2 /MMAO being the most highly active catalytic system showing the highest activity of 9.41 × 10⁶ g of PE (mol of Co)^?1 h^?1 which is three times higher than that of prototypal cobalt catalyst ( Co0 ) under identical conditions. Moreover, high melt temperature and unimodal molecular weight distribution are the characteristics of the resulting polyethylene.     

Synthesis,anticancer, molecular docking and QSAR studies of benzoylhydrazone

To find out effective anticancer compounds we synthesized (1–30) derivatives of 4-isopropylbenzoylhydrazone and evaluated for anticancer potential. The compounds 3, 9, 12, 23, 26 and 28 showed better activities ranging (0.39–1.1 µg/ml) than the standard (1.53 ± 0.01 µg/ml). In line with this, compounds 2, 6, 24, 25 and 29 exhibited better activities compared to the second standard (5FU 4.60 ± 0.01 µg/ml). The best molecular docked complex between the BRCA1 structure and the 1–30 derivatives were analyzed based on the Glide docked score and binding orientation for both the SP and XP mode. The 2D-QSAR analysis reflected a significant correlation between the experimental and the predicted biological activities. The above-mentioned compounds were also assessed by various spectroscopic techniques.     

Synthesis of Novel N-Acylhydrazones and Their C-N/N-N Bond Conformational Characterization by NMR Spectroscopy

In this article, a synthesis of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides and their structural interpretation by NMR experiments is described in an attempt to explain the duplication of some peaks in their ¹H- and ¹³C-NMR spectra. Twenty new 6-methyl-1H-pyrazolo[3,4-b]quinoline substituted N-acylhydrazones 6(a–t) were synthesized from 2-chloro-6-methylquinoline-3-carbaldehyde (1) in four steps. 2-Chloro-6-methylquinoline-3-carbaldehyde (1) afforded 6-methyl-1H-pyrazolo[3,4-b]quinoline (2), which upon N-alkylation yielded 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetate (3). The hydrazinolysis of 3 followed by the condensation of resulting 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazide (4) with aromatic aldehydes gave N-acylhydrazones 6(a–t). Structures of the synthesized compounds were established by readily available techniques such as FT-IR, NMR and mass spectral studies. The stereochemical behavior of 6(a–t) was studied in dimethyl sulfoxide-d₆ solvent by means of ¹H NMR and ¹³C NMR techniques at room temperature. NMR spectra revealed the presence of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides as a mixture of two conformers, i.e., E_(C=N)(N-N) synperiplanar and E_(C=N)(N-N) antiperiplanar at room temperature in DMSO-d₆. The ratio of both conformers was also calculated and E_{(C=N) (N-N)} syn-periplanar conformer was established to be in higher percentage in equilibrium with the E_{(C=N) (N-N)} anti-periplanar form.     

Antibiofilm,Anti-Quorum Sensing Activities,and Molecular Docking Studies of Seriphidium quettense Essential Oil

Chemistry of Natural Compounds -     

Highly diastereo- and regioselective transition metal-catalyzed additions of metal hydrides and bimetallic species to cyclopropenes: easy access to multisubstituted cyclopropanes

The first highly efficient, diastereo- and regioselective transition metal-catalyzed addition of metal hydrides (stannanes, silanes, and germanes) and bimetallic species (ditins and silyltins) to cyclopropenes has been developed. It was shown that the addition across the double bond of cyclopropenes is generally controlled by steric factors and proceeds from the least hindered face. This methodology represents a powerful and atom-economic approach toward a wide variety of highly substituted stereodefined cyclopropylmetals, useful building blocks unavailable by other methods.