European Journal of Molecular Biotechnology

69-75

Authors: Abdelilah Benallou

The optimum geometries and quadratic force constants of HCN, HNC, intermediates (INT1 and INT2) and the transition state connecting them (CHN) have been determined at the DFT (density functional theory) level of theory. Energy differences were evaluated using the DFT method in conjunction with 6-311++g(d,p) basis set. The most reliable structure obtained for the transition state has bond distances of 1.184, 1.193 and 1.391Å for rCN, rCH and rNH, respectively. Including a correction for zero-point vibrational energies, the transition state activation energy is predicted to be 44.6kcal/mol. So the transition state of isomerization pathway is highly energetic and subsequently cannot occur efficiently in the gas phase.

83-95

Authors: H.A. Shindy, M.A. El-Maghraby, M.M. Goma a, N.A. Harb

New polyheterocyclic starting material compound namely 3, 5-dimethyl-7-phenyl-furo [(3,2-d) pyrazole;(3',2'-d) oxazole] was prepared and oriented for the synthesis of novel monomethine cyanine dyes (simple cyanine dyes), bis monomethine cyanine dyes (bis simple cyanine dyes), trimethine cyanine dyes (carbocyanine dyes) and bis trimethine cyanine dyes (bis carbocyanine dyes). The electronic transitions of all the synthesized cyanine dyes were evaluated and determined through investigating their visible absorption spectra in 95 % ethanol solution. The dyes were thought to be better electronic transitions when they absorb light at higher wavelength bands (bathochromic shifted and/or red shifted dyes). Consequently, the electronic transitions of the dyes decreases when they absorb light at lower wavelength bands (hypsochromic shifted and/or blue shifted dyes). The antimicrobial activity evaluation for a number of 10 (ten) selected compounds was tested against 4 (four) various bacterial strains (Bacillus subtilis, Escherichia coli, Pseudomona aeruginosa and Staphylococcus aureus). The antimicrobial activity evaluation can be made through measuring the inhibition zone diameter of the tested compounds against a number of bacterial and/or fungi strains. The compounds were thought to be better antimicrobial active when they give higher inhibition zone diameter against the tested bacterial and/or the fungi strains. Consequently, the antimicrobial activity of the compounds decrease when they give lower inhibition zone diameter against the tested bacterial and/or the fungi strains. Structural characterization and determination was carried out via elemental analysis, visible, mass, IR and 1HNMR spectroscopic data.