Pyridine-containing octadentate ligand NE3TA-PY for formation of neutral complex with 177Lu(III) and 90Y(III) for radiopharmaceutical applications: Synthesis, DFT calculation, radiolabeling, and in vitro complex stability

2021 ◽  
pp. 111436
Author(s):  
Hyun-Soon Chong ◽  
Yunwei Chen ◽  
Chisoo Kang ◽  
Inseok Sin ◽  
Shuyuan Zhang ◽  
...  
Keyword(s):  
Dft Calculation ◽  
Complex Stability ◽  
Neutral Complex ◽  
Octadentate Ligand

scholarly journals Promising bifunctional chelators for copper 64-PET imaging: practical 64Cu radiolabeling and high in vitro and in vivo complex stability

2015 ◽  
Vol 21 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Ningjie Wu ◽  
Chi Soo Kang ◽  
Inseok Sin ◽  
Siyuan Ren ◽  
Dijie Liu ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Complex Stability ◽  
Bifunctional Chelators

Structure, photophysics, electrochemistry, DFT calculation, and in-vitro antioxidant activity of coumarin Schiff base complexes of Group 6 metal carbonyls

2011 ◽  
Vol 105 (4) ◽  
pp. 577-588 ◽  
Author(s):  
Papia Datta ◽  
Ambika Prasad Mukhopadhyay ◽  
Prasenjit Manna ◽  
Edward R.T. Tiekink ◽  
Parames Chandra Sil ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Schiff Base ◽  
Dft Calculation ◽  
Schiff Base Complexes ◽  
Metal Carbonyls ◽  
Group 6 ◽  
In Vitro Antioxidant Activity

scholarly journals Properties of Escherichia coli RNA polymerase from a strain devoid of the stringent response alarmone ppGpp.

2008 ◽  
Vol 55 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Agnieszka Szalewska-Pałasz
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Stringent Response ◽  
In Vitro Transcription ◽  
Complex Stability ◽  
Wild Type ◽  
Guanosine Tetraphosphate ◽  
Sigma 70 ◽  
In Vitro Performance

The stringent response alarmone guanosine tetraphosphate (ppGpp) affects transcription from many promoters. ppGpp binds directly to the transcription enzyme of Escherichia coli, RNA polymerase. Analysis of the crystal structure of RNA polymerase with ppGpp suggested that binding of this nucleotide may result in some conformational or post-translational alterations to the enzyme. These changes might affect in vitro performance of the enzyme. Here, a comparison of the in vitro properties of RNA polymerases isolated from wild type and ppGpp-deficient bacteria shows that both enzymes do not differ in i) transcription activity of various promoters (e.g. sigma(70)-rrnB P1, lambdapL, T7A1), ii) response to ppGpp, iii) promoter-RNA polymerase open complex stability. Thus, it may be concluded that ppGpp present in the bacterial cell prior to purification of the RNA polymerase does not result in the alterations to the enzyme that could be permanent and affect its in vitro transcription capacity.

Relationship between Complex Stability and Biokinetics of 99mTc-Phosphate Compounds

1980 ◽  
Vol 19 (01) ◽  
pp. 07-10
Author(s):  
T. Körfgen ◽  
G. Hoffmann ◽  
C. Schiimichen
Keyword(s):  
Stable Complex ◽  
Bone Imaging ◽  
Complex Stability ◽  
Albumin Solution ◽  
Adult Rat ◽  
Phosphate Compound ◽  
The Stability ◽  
Bone Imaging Agent ◽  
Phosphate Compounds

The complex inertness of 99mTc-EHDP, -MDP, -PPi and -TriP was determined in vitro by means of protein binding of 99mTc after dilution in a phosphate-buffered albumin solution. Commercially available kits were used. In vitro, 99mTc- EHDP was found to be the most stable complex. The biodistribution of these agents was evaluated in the adult rat; here the less stable 99mTc-MDP proved to be the superior bone imaging agent. It is suggested that the complex inertness and the bone affinity are opposing properties of the 99mTc-phosphate compounds, because the complex must hydrolyse before the phosphate compound and technetium (IV) are deposited separately in bone. Hence, bone imaging with 99mTc-phosphate compounds demands a compromise concerning the stability of these complexes at low ligand concentrations, which among the investigated agents is best accomplished by 99mTc-MDP.

Octadentate catecholamide ligands for Pu(IV) based on linear or preorganized molecular backbones

1996 ◽  
Vol 15 (4) ◽  
pp. 352-360 ◽  
Author(s):  
PW Durbin ◽  
B. Kullgren ◽  
N. Jeung ◽  
J. Xu ◽  
SJ Rodgers ◽  
...  
Keyword(s):  
Metal Binding ◽  
Intraperitoneal Injection ◽  
Equimolar Amount ◽  
The Body ◽  
Whole Body ◽  
Great Stability ◽  
Gastric Intubation ◽  
Octadentate Ligand

Nine new octadentate ligands based on cyclic, spermine (3,4,3-LI), desferrioxamine (DFO), or H-shaped tetrakis amine (penten) molecular backbones were prepared containing catecholamide (CAM), carboxycatecholamide (CAM(C)), or terephthalamide (TAM) chelating units. Mice were injected intravenously with 238Pu(IV) citrate, treated with 30 μmol kg-1 of a ligand by intraperitoneal injection at 1 h or by gastric intubation at 3 min, and Pu retention in tissues and Pu transfer to excreta were measured at 24 h. Given by injection, three soluble ligands composed of MeTAM (3,4,3-LIMeTAM, DFO-MeTAM, H(2,2)-MeTAM) reduced Pu retention in the body to 27- 28% of control compared with 32 and 37% of control obtained in mice similarly treated with 3,4,3-LICAM(C) or CaNa3-DTPA, respectively. The MeTAM ligands reduced Pu retention in the skeleton as much as an equimolar amount of CaNa 3-DTPA, while Pu retention in the liver (on average, 16% of control) was significantly less than was obtained with CaNa3-DTPA (35% of control). Given orally, H(2,2)-MeTAM reduced Pu retention in the whole body to 58% of control compared with reductions to 62 and 94% of control achieved with 3,4,3-LICAM(C) or CaNa3-DTPA, respectively. Penten is both partially preorganized for metal binding and spatially suitable for encapsulation of actinide(IV), and ligands with the penten backbone are easier and less costly to prepare than those based on spermine or DFO. The biological results confirmed that penten is a suitable as well as practical structural backbone for new octadentate ligands. In agreement with the great stability of the ferric complex with MeTAM, as determined in vitro, the small, simple, soluble penten- based octadentate ligand, H(2,2)-MeTAM, was shown to be, overall, the most effective catecholamide ligand for enhancing Pu excretion. Either combined in H(2,2)- MeTAM or separately, the penten backbone and the MeTAM chelating unit are potentially useful additions to the set of backbones and binding units of multidentate ligands identified as effective for in vivo chelation of the actinides.

scholarly journals Synthesis, In Silico Prediction and In Vitro Evaluation of Antimicrobial Activity, DFT Calculation and Theoretical Investigation of Novel Xanthines and Uracil Containing Imidazolone Derivatives

2021 ◽  
Vol 22 (20) ◽  
pp. 10979
Author(s):  
Samar El-Kalyoubi ◽  
Fatimah Agili ◽  
Wael A. Zordok ◽  
Ashraf S. A. El-Sayed
Keyword(s):  
Acetic Acid ◽  
Theoretical Investigation ◽  
Polyketide Synthase ◽  
Dft Calculation ◽  
Acyl Carrier Protein ◽  
Docking Study ◽  
Antibacterial Activities ◽  
Protein Domain ◽  
Type I

Novel xanthine and imidazolone derivatives were synthesized based on oxazolone derivatives 2a-c as a key intermediate. The corresponding xanthine 3-5 and imidazolone derivatives 6-13 were obtained via reaction of oxazolone derivative 2a-c with 5,6-diaminouracils 1a-e under various conditions. Xanthine compounds 3-5 were obtained by cyclocondensation of 5,6-diaminouracils 1a-c with different oxazolones in glacial acetic acid. Moreover, 5, 6-diaminouracils 1a-e were reacted with oxazolones 2a-c in presence of drops of acetic acid under fused condition yielding the imidazolone derivatives 6-13. Furthermore, Schiff base of compounds 14-16 were obtained by condensing 5, 6-diaminouracils 1a,b,e with 4-dimethylaminobenzaldehyde in acetic acid. The structural identity of the resulting compounds was resolved by IR, 1H-, 13C-NMR and Mass spectral analyses. The novel synthesized compounds were screened for their antifungal and antibacterial activities. Compounds 3, 6, 13 and 16 displayed the highest activity against Escherichia coli as revealed from the IC50 values (1.8–1.9 µg/mL). The compound 16 displayed a significant antifungal activity against Candia albicans (0.82 µg/mL), Aspergillus flavus (1.2 µg/mL) comparing to authentic antibiotics. From the TEM microgram, the compounds 3, 12, 13 and 16 exhibited a strong deformation to the cellular entities, by interfering with the cell membrane components, causing cytosol leakage, cellular shrinkage and irregularity to the cell shape. In addition, docking study for the most promising antimicrobial tested compounds depicted high binding affinity against acyl carrier protein domain from a fungal type I polyketide synthase (ACP), and Baumannii penicillin- binding protein (PBP). Moreover, compound 12 showed high drug- likeness, and excellent pharmacokinetics, which needs to be in focus for further antimicrobial drug development. The most promising antimicrobial compounds underwent theoretical investigation using DFT calculation.

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