Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...

A new formulation of a pose refinement technique using “active” models is described. An error term derived from the detection of image derivatives close to an initial object hypothesis is linearised and solved by least squares. The method is particularly well suited to problems involving external geometrical constraints (such as the ground-plane constraint). We show that the method is able to r...

Four fundamental physical parameters of series of benzene derivatives were studied to ascertain correlations with biological activity. These included octanol/water coefficient, vapor pressure, infrared absorption (out-of-plane C-H vibration), and the pi values. Each physicochemical constant exhibited a partial correlation with biological activity suggesting that each played a role. It was presu...

The effect of arbidol and its structural analogues on the process of lipid peroxidation in phospholipid liposomes induced by Fe2+ has been investigated. It was shown that the antioxidant efficacy of arbidol and its derivatives is lower than that of alpha-tocopherol by two or three times. It was suggested that the mechanism antioxidant action of the arbidol and its structural analogues consists ...

The reductions of either acyl or alkyl derivatives of dihydroxyacetone phosphate by enzymes from ascites tumor cell microsomes with NADPH were studied. The reaction rate was measured by determining the formation of labeled lipid from [4-3H]NADPH. The products were characterized as either 1-acyl or 1-alkyl [2-3H]glycerol d-phosphate formed from the corresponding keto derivatives. The enzymes wer...

Ionizing radiation (IR) triggers mitochondrial overproduction of H2O2 and accumulation of lipid hydroperoxides leading to the induction of apoptotic and necroptotic cell death pathways. Given the high catalytic efficiency of the seleno-enzyme glutathione peroxidase (Gpx) toward reduction of lipid hydroperoxides and H2O2, we tested the potential of mitochondria-targeted derivatives of ebselen to...

A series of amides of the antifungal antibiotic amphotericin B (AmB) and its conjugates with benzoxaboroles was tested to determine whether they form pores in lipid bilayers and to compare their channel characteristics. The tested derivatives produced pores of larger amplitude and shorter lifetime than those of the parent antibiotic. The pore conductance was related to changes in the partial ch...

Acid-catalysed, '3+3' condensation of m-bispyrryl benzene derivatives with acetone afforded new non-aromatic macrocycles that can be converted to meso-alkylidenyl dibenzohexaphyrins carrying four exocyclic double bonds at meso-positions by DDQ oxidation.

We have recently identified low-molecular weight compounds that act as inhibitors of Lipid II, an essential precursor of bacterial cell wall biosynthesis. Lipid II comprises specialized lipid (bactoprenol) linked to a hydrophilic head group consisting of a peptidoglycan subunit (N-acetyl glucosamine [GlcNAc]-N-acetyl muramic acid [MurNAc] disaccharide coupled to a short pentapeptide moiety) via...