Experimental and computational study on 2,2'-[(1E,2E)-hydrazine-1,2-diylidenedi(1E)eth-1-yl-1-ylidene]diphenol and its Ni(II), Pt(II), Pd(II) complexes.

2,2'-[(1E,2E)-hydrazine-1,2-diylidenedi(1E)eth-1-yl-1-ylidene]diphenol and its dimeric, binuclear Ni(II), Pd(II) and Pt(II) metal complexes were synthesized. Hydrazine derivative and its complexes were characterized by elemental analyses, LC-MS, IR, electronic spectra, (1)H and (13)C NMR spectra, conductivity and magnetic measurements. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The antibacterial activities of synthesized compounds were studied against some Gram-positive and Gram-negative bacteria by using the microdilution and disk diffusion method. As the antibacterial activity results evidently show, the compound possessed a broad spectrum of activity against the tested bacteria.

Screening of novel chemical compounds as possible inhibitors of carbonic anhydrase and photosynthetic activity of photosystem II.

Thirty novel chemical compounds were designed and synthesized expecting that they would be possible inhibitors. From this number eleven were organic bases, twenty-four were their organic derivatives and fourteen were metal complexes. Screening of these chemicals by their action on photosynthetic electron transfer (PET) and carbonic anhydrase (CA) activity (CAA) of photosystem II (PSII), α-CA, as well as ß-CA was done. Several groups were revealed among them. Some of them are capable to suppress either one, two, three, or even all of the measured activities. As example, one of the Cu(II)-phenyl sulfonylhydrazone complexes (compound 25) suppresses CAA of α-CA by 88%, CAA of ß-CA by 100% inhibition; CAA of PSII by 100% and the PSII photosynthetic activity by 66.2%. The Schiff base compounds (12, 15) and Cu(II)-phenyl sulfonylhydrazone complexes (25, 26) inhibited the CAA and PET of PSII significantly. The obtained data indicate that the PSII donor side is a target of the inhibitory action of these agents. Some physico- or electrochemical properties such as diffusion coefficient, number of transferred electrons, peak potential and heterogeneous standard rate constants of the compounds were determined in nonaqueous media. pKa values were also determined in nonaqueous and aqueous media. Availability in the studied group of novel chemical agents possessing different inhibitory activity allow in future to isolate the "active part" in the structure of the inhibitors responsible for different inhibitory mechanisms, as well as to determine the influence of side substituters on its inhibitory efficiency.

Synthesis, characterization and anti-microbial evaluation of Cu(II), Ni(II), Pt(II) and Pd(II) sulfonylhydrazone complexes; 2D-QSAR analysis of Ni(II) complexes of sulfonylhydrazone derivatives.

Copper(II), nickel(II), platinum(II) and palladium(II) complexes with 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) derived from propanesulfonic acid-1-methylhydrazide (psmh) were synthesized, their structure were identified, and antimicrobial activity of the compounds was screened against three Gram-positive and three Gram-negative bacteria. The results of antimicrobial studies indicate that Pt(II) and Pd(II) complexes showed the most activity against all bacteria. The crystal structure of 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) was also investigated by X-ray analysis. A series of Ni(II) sulfonyl hydrazone complexes (1-33) was synthesized and tested in vitro against Escherichia coli and Staphylococcus aureus. Their antimicrobial activities were used in the QSAR analysis. Four-parameter QSAR models revealed that nucleophilic reaction index for Ni and O atoms, and HOMO-LUMO energy gap play key roles in the antimicrobial activity.

Conformational analysis, vibrational and NMR spectroscopic study of the methanesulfonamide-N,N'-1,2-ethanediylbis.

A conformational analysis of the methanesulfonamide-N,N'-1,2-ethanediylbis (msen) was performed by using vibrational and NMR spectroscopies as well as theoretical computations. The possible stable conformers of msen on its potential energy surface were investigated by semi-empirical PM5 method and appropriate structures were defined with B3LYP hybrid density functional theory (DFT) method along with the basis sets of different size and type. Six different rotational isomers were found as the result of DFT calculation. The two isomer, called trans-trans-gauche(+)-eclipsed, synperiplanar (ttg(+)-e,bis) and trans-gauche(+)-gauche(-)-staggered, antiplanar (tg(+)g(-)-s,anti), were considered in the vibrational spectral analysis. The infrared (4000-30 cm(-1)) and Raman (4000-60 cm(-1)) spectra of msen were measured in solid state. For a complete assignment of the vibrational spectra, DFT calculations at B3LYP/6311-G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology was performed. Furthermore, (13)C and (1)H NMR analyses were performed for six conformers at B3LYP/6-311++G(d,p) level of theory and compared with the experimental findings. Results from experimental and theoretical data showed the ttg(+)-e,bis to be the most stable form of a msen molecule.

Synthesis, characterization and antimicrobial activity of new aliphatic sulfonamide.

A series of novel aliphatic sulfonamide derivatives (1-7) were synthesized and characterized by elemental analyses, FT-IR, (1)H NMR, (13)C NMR and LC-MS techniques. All the synthesized compounds were evaluated in vitro as antimicrobial agents against representative strains of Gram-positive (Staphylococcus aureus ATCC 25953, Bacillus cereus ATCC 6633 and Listeria monocytogenes ATCC Li6 (isolate), Gram-negative bacteria (Escherichia coli ATCC 11230) and antifungal agent against Candida albicans (clinical isolate) by both disc diffusion and minimal inhibition concentration (MIC) methods. All these bacteria and fungus studied were screened against some antibiotics to compare with our chemicals' zone diameters. Our aliphatic sulfonamides have highest powerful antibacterial activity for Gram-negative bacteria than Gram-positive bacteria and antibacterial activity decreases as the length of the carbon chain increases.