scholarly journals Ligational Behavior of Synthesized New Hydrazones Towards Oxovanadium (IV) Complexes and Their Antituberculosis Aspects

Author(s):  
Dr. Alok Chandrayan ◽  
Dr. Alka Pradhan

The synthesis of some oxovanadium (IV) complexes with bidentate ligands (new synthesized biologically active hydrazones) derived from 2-methyl-4-(N-cyanoethyl)-N-benzenesulphonyl-benzylidene-3-oxo-[N-(substituted-1-phenyl)propanamido] hydrazone were analyzed.The complexes prepared were of the type [VO.L2] (where L= different new synthesized hydrazones).The characterization of these newly synthesized hydrazones and their metal complexes were done by IR, 1H-NMR spectral studies and elemental analysis. The infrared data of these complexes revealed the bidentate nature of the ligands and coordination to imino nitrogen of the amido group and azomethinic-nitrogen atoms. The new products were synthesized and evaluated for anti-tuberculosis activity against Mycobacterium tuberculosis H37RVin L.J.medium. The biological screening data indicates that the metal chelates are more potent than the parent ligands.

Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.


2018 ◽  
Vol 18 (14) ◽  
pp. 1167-1174 ◽  
Author(s):  
Petra Lovecka ◽  
Jan Lipov ◽  
Kamila Thumova ◽  
Anna Macurkova

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 667 ◽  
Author(s):  
Carolina Proaño-Bolaños ◽  
Ailín Blasco-Zúñiga ◽  
José Rafael Almeida ◽  
Lei Wang ◽  
Miguel Angel Llumiquinga ◽  
...  

Frog skin secretions contain medically-valuable molecules, which are useful for the discovery of new biopharmaceuticals. The peptide profile of the skin secretion of Agalychnis spurrelli has not been investigated; therefore, the structural and biological characterization of its compounds signify an inestimable opportunity to acquire new biologically-active chemical scaffolds. In this work, skin secretion from this amphibian was analysed by molecular cloning and tandem mass spectrometry. Although the extent of this work was not exhaustive, eleven skin secretion peptides belonging to five peptide families were identified. Among these, we report the occurrence of two phyllokinins, and one medusin-SP which were previously reported in other related species. In addition, eight novel peptides were identified, including four dermaseptins, DRS-SP2 to DRS-SP5, one phylloseptin-SP1, and three orphan peptides. Phylloseptin-SP1 and dermaseptins-SP2 were identified in HPLC fractions based on their molecular masses determined by MALDI-TOF MS. Among the antimicrobial peptides, dermaseptin-SP2 was the most potent, inhibiting Escherichia coli, Staphylococcus aureus, and ORSA with a minimum inhibitory concentration (MIC) of 2.68 μM, and Candida albicans with an MIC of 10.71 μM, without haemolytic effects. The peptides described in this study represent but a superficial glance at the considerable structural diversity of bioactive peptides produced in the skin secretion of A. spurrelli.


1969 ◽  
Vol 62 (3) ◽  
pp. 521-536 ◽  
Author(s):  
M. L. Aubert ◽  
J.-P. Felber

ABSTRACT In investigations on the production and the specificity of anti-ACTH antibodies used for radioimmunoassay, differences have been observed between the various antibodies obtained. It was shown by means of competitive inhibition with different ACTH fragments that the binding of the ACTH molecule to its antibody can occur at different sites along the ACTH peptide. By varying the concentrations of the fragments and the conditions of the assays, it was possible to study the properties of each antibody. Thus antibodies which bind the N-terminal portion, or which exclusively bind the biologically active part of the ACTH chain (1–20), are the most suitable for radioimmunoassay. It was found, however, that the production of antiserum was generally more frequent when binding occurred to the C-terminal portion of the ACTH peptide. Should the presence of such fragments in plasma be confirmed, then the use of these antisera could lead to erroneous measurement of biologically inactive ACTH fragments. Thus, this study reveals that a selection of the antibody for specificity might be necessary for its application to the radioimmunoassay of plasma ACTH, and that this selection could be performed with the use of ACTH fragments. An approach to the problem of binding sites between antigen and antibody has been described and the possibility of introducing a radioimmunoassay for plasma ACTH fragments discussed.


2007 ◽  
Vol 361-363 ◽  
pp. 733-736 ◽  
Author(s):  
D. Ionita ◽  
E. Aldea ◽  
G. Stanciu ◽  
Ioana Demetrescu

The aim of this paper was to find and establish the contact: biomaterial implant (TiAlZr) - coated with biologically active molecules; and the correlation between surface characteristics and their efficiency.


1994 ◽  
Vol 5 (12) ◽  
pp. 1493-1506 ◽  
Author(s):  
Laurence Zitvogel ◽  
Hideaki Tahara ◽  
Quan Cai ◽  
Walter J. Storkus ◽  
Gunhild Muller ◽  
...  

1995 ◽  
Vol 7 (4) ◽  
pp. 263-272 ◽  
Author(s):  
Ewan Morrison ◽  
Peter Tomasec ◽  
Elizabeth A. Linton ◽  
Philip J. Lowry ◽  
Pedro R. Lowenstein ◽  
...  

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