Naz Mohammed Aghatabay

Synthesis and investigation of antimicrobial activity of some bisbenzimidazole-derived chelating agents.

The 1,2-bis(2-benzimidazyl)-1,2-ethanediol (1), 1,4-bis(2-benzimidazyl)-1,2,3,4-butanetetraol (2), 1,3-bis(2-benzimidazyl)-2-thiapropane (3), 1,3-bis(2-benzimidazyl)-2-thia-propane-dihydrochloride (4), 1,5-bis(2-benzimidazyl)-3-thiapentane (5), and 1,5-bis(2-benzimidazyl)-3-thiapentane dihydrochloride (6) chelating ligands are synthesised and characterised by using analytical data and modem spectroscopic methods such as FT-Raman, FT-IR, 1H- and 13C-NMR spectrometers. Their antimicrobial activities are reported by comparing the in vitro activities, with those of ofloxacin, ciprofloxacin, piperacillin, ampicillin and cefazolin antibacterial agents against fresh clinical isolates. Antifungal activities are reported on Candida albicans, Candida utilis, Cryptococcus neoformans fungi, and the results are referenced with amphotericin-B, fluconazole and flucytosine antifungal agents. It has been found that all the compounds have broad spectra activity and was either more active or equipotent to those compared antibiotic and antifungal agents.

Synthesis, characterization and antimicrobial activity of water soluble dendritic macromolecules.

Several families of water soluble dendrimers were synthesized based on poly(propyleneoxide) amines (Jeffamines) (P(1)). P(1)-core and branched units were constructed from both methylacrylate and ethylenediamine (P(2)-P(9), and generations 0-3 with -NH(2), -COOH functionalities). They were characterized by elemental analysis (EA), gel permeation chromatography (GPC), FT-IR, (1)H, and (13)C NMR. The antimicrobial activities of only water soluble compounds (P(1), P(3), P(4), P(6), P(7) and P(9)) were evaluated using disk diffusion method in water as well as the minimal inhibitory concentration (MIC) dilution method against 9 bacteria. The obtained results from disk diffusion method are assessed in side-by-side comparison with those of Penicillin-g, Ampicillin, Cefotaxime, Vancomycin, Oflaxacin, and Tetracycline, well-known antibacterial agents. The results from dilution procedure are compared with Gentamycin as antibacterial and Nystatin as antifungal. The antifungal activities are reported on five yeast cultures namely, Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, and Hanseniaspora guilliermondii, and the results are referenced with Nystatin, Ketaconazole, and Clotrimazole, commercial antifungal agents. In most cases, the compounds show broad-spectrum (gram-positive and gram-negative bacteria) activities that are comparatively higher or equipotent to the antibiotic and antifungal agents in the comparison tests.

1,2-Bis-(2-benzimidazolyl)-1,2-ethanediol and 1,4-bis-(2-benzimidazolyl)-1,2,3,4-butanetetraol PdCl2 complexes

The 1,2-bis-(2-benzimidazolyl)-1,2-ethanediol (EH2) and 1,4-bis-(2-benzimidazolyl)-1,2,3,4-butanetetraol (TH4) ligands form 4-coordinate mono- and bi-metallic complexes with PdCl2, respectively. In Pd(EH2)Cl2 the ligand acts as a bidentate through two of the nitrogen atoms. On the other hand, in Pd2(TH4)Cl4 the ligand coordinates to two palladium atoms through both bis-benzimidazole nitrogen atoms and two oxygen atoms of the hydroxy groups, forming two different isomers. The complexes were characterised by analytical data, magnetic susceptibility, molar conductivity, and also by i.r., 1H- and 13C-n.m.r. spectra.

Synthesis, Raman, FT-IR, NMR spectroscopic data and antimicrobial activity of mixed aza-oxo-thia macrocyclic compounds

Mixed aza-oxo-thia macrocyclic ligands 1,3,5,11,13,15-hexaaza-6,10,16,20-tetraoxo-8,18-dithia-2,3,4:12,13,14-dipyridine cyclocosane (L(1)); 1,3,5,12,14,16-hexeaza-6,11,17,22-tetraoxo-8,9,19,20-tetrathia-2,3,4:13,14,15-dipyridine cyclodocosane (L(2)); 1,3,5,13,15,17-hexaaza-6,12,18,24-tetraoxo-9,21-dithia-2,3,4:14,15,16-dipyridine cyclotetracosane (L(3)) and 1,3,5,14,16,18-hexaaza-6,13,19,26-tetraoxo-9,10,22,23-tetrathia-2,3,4:15,16,17-dipyridine cyclohexacosane (L(4)) were synthesised. The structural features of the ligands have been studied by elemental analyses, Raman, IR, (1)H and (13)C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against nine bacteria. The obtained results from disk diffusion method were assessed in side-by-side comparison with those of penicillin G, ampicillin, cefotaxime, vancomycin, ofloxacin, and tetracycline well known antibacterial agents. The results from dilution procedure were compared with gentamycin as antibacterial and nystatin as antifungal. The antifungal activities are reported on five yeast cultures namely Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, and Hanseniaspora guilliermondii, and the results are referenced with nystatin, Ketoconazole, and clotrimazole, commercial antifungal agents. In most cases, the compounds show broad-spectrum (Gram(+) and Gram(-) bacteria) activities that were more active or equipotent to the antibiotic and antifungal agents in the comparison tests.

Synthesis, Raman, FT-IR, NMR spectroscopic characterization, antimicrobial activity, cytotoxicity and DNA binding of new mixed aza-oxo-thia macrocyclic compounds

Series of new mixed aza-oxo-thia macrocyclic ligands 1,9(2,6)-ditriazina-2,8,10,16-tetraaza-3,7,11,15-tetraoxo-5,13-dithia-cyclohexadecaphan-1(4),9(4)-diphenyl (L(1)); 1,10(2,6)-ditri azina-2,9,11,18-tetraaza-3,8,12,17-tetraoxo-5,6,14,15-tetrathia-cyclooctadecaphan-1(4),10(4)-diphenyl (L(2)); 1,11(2,6)-ditriazina-2,10,12,20-tetraaza-3,9,13,19-tetraoxo-6,16-dithia-cyclocosa-phan-1(4),11(4)-diphenyl (L(3)); 1,12(2,6)-ditriazina-2,11,13,22-tetraaza-3,10,14,21-tetraoxo-6,7,17,18-tetrathia-cyclodocosaphan-1(4),12(4)-diphenyl (L(4)) were synthesised. The structural features of the compounds have been studied by elemental analyses, Mass, FT-Raman, FT-IR, (1)H and (13)C NMR spectroscopy. The antimicrobial activities of the ligands were evaluated using disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against several bacteria and yeast cultures. The obtained results from both methods were assessed in side-by-side comparison with commercial antibacterial and antifungal agents. In most cases, the compounds show strong antifungal activity in the comparison tests. Cytotoxic activities of the ligands against two different human cancer cell lines, stomach (23132/87) and lung (A549) were determined by MTT assay. DNA fragmentation assay tested cell lines were used to analyze the DNA ladder formation which is a characteristic of apoptotic cell death. The binding of the ligands with calf thymus DNA (CT-DNA) has also been investigated by absorption spectroscopy.

Tautomeric conversion, vibrational spectra, and density functional studies on peripheral sulfur derivatives of benzothiazole and benzothiazoline isomers.

The room temperature structural (tautomerism, dimerization, conformational preference, geometry parameters) and vibrational spectral (IR and Raman) analyses have been performed on benzothiazoline (benzothiazoline-2-thione, 3-methyl-benzothiazoline-2-thione) and benzothiazole [2-mercaptobenzothiazole, 2-methylthiobenzothiazole, and bis(benzothiazole-2-ylthio)ethane] derivatives at the B3LYP/6-311++G(∗∗) level of theory. Although the keto to enol transition barriers are too high over the most stable benzothiazoline isomers, vibrational spectral analyses reveal some major bands of benzothiazole isomers in the present room temperature experimental FT-IR and FT-Raman specta. Therefore, benzothiazole isomers exist at rare amounts in the powdered samples that are mainly composed of benzothiazoline isomers. The benzothiazole isomers have two stable conformations due to the orientation of their SH and SCH3 moieties. The energetic and vibrational spectral analyses suggest that the benzothiazoline-2-thione molecules can be stabilized further through the NH⋯S intermolecular hydrogen bonds in solid phase. All observed fundamental vibrational bands of the molecules have been assigned based on the calculated mode frequencies and IR/Raman intensities. The mode assignments have been expressed in terms of internal coordinates and their percent potential energy distributions. The effects of substitution at the nitrogen and peripheral sulfur atoms have been analyzed for the geometries and vibrational bands of the molecules.

Synthesis, structural aspects, antimicrobial activity and ion transport investigation of five new [1+1] condensed cycloheterophane peptides

Five novel [1+1] condensed cycloheterophane peptides were synthesized via reaction of pyridine-2,6-bis(2-aminothiophenoxymethyl) with several diacid chlorides: glutaryl dichloride, adipoyl dichloride, 2,2′-thiodiacetyl chloride, dithiodiglycoloyl chloride and 3,3′-thiodipropionoyl chloride combinations (L1–L5). The compounds were characterized by elemental analyses, mass, FT-IR, 1H, and 13C NMR spectral data. The antimicrobial activities of the compounds were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimal inhibitory concentration dilution method, against several bacteria and yeast cultures. The results were compared with those of commercial antibiotic and antifungal agents. Structure activity relationships were also discussed. Permeability of compound L5 against Na+ and K+ were also investigated.Graphical abstractFive novel cycoloheterophane amides were synthesized. Mass spectra reveal their [1+1] cyclic condensation. The compounds exert moderate microbial activity. Thia and aza groups seem to be a key element of microbial potency.

Synthesis, structural aspects, and antimicrobial activity investigation of novel macrocyclic amide-containing compounds

Macrocyclic 16,76-dimethyl-1,7(2,4)-ditriazina-2,6,8,12-tetraaza-3,5,9,11-tetraoxocyclododecaphane, 16,86-dimethyl-1,8(2,4)-ditriazina-2,7,9,14-tetraaza-3,6,10,13-tetraoxocyclotetradecaphane, 16,96-dimethyl-1,9(2,4)-ditriazina-2,8,10,16-tetraaza-3,7,11,15-tetraoxocyclohexadecaphane, and 16,106-dimethyl-1,10(2,4)-ditriazina-2,9,11,18-tetraaza-3,8,12,17-tetraoxocyclooctadecaphane are synthesized. The compounds are characterized by elemental analyses, Raman, IR, 1H, 13C NMR and mass spectral data. The antimicrobial activities of the compounds are evaluated against several bacteria and yeast cultures and the results were compared with those of commercial antibiotic and antifungal agents. Structure–activity relationships are also discussed.