The selective cyclohexane oxidation to cyclohexanone and cyclohexanol based on a green strategy has been a challenge. A new manganese porphyrin [MnIII(T2,4,5TMPP)Cl] was prepared and its activity and selectivity as a catalyst were studied together with the classical manganese porphyrin [MnIII(TP...

Visible light photolysis of dimanganese(III) μ-oxo bis-porphyrins, [MnIII(Por)]2O, was studied in three porphyrin systems with different electronic structures. Direct conversion of manganese (III) μ-oxo dimers to manganese(IV)-oxo porphyrins plus manganese(III) products has been observed in be...

With iodobenzene diacetate [PhI(OAc)2] as the oxygen source, manganese(III) porphyrin complexes exhibit remarkable catalytic activity toward the selective oxidation of alkenes and activated hydrocarbons. Conspicuous is the fact that the readily soluble PhI(OAc)2 in the presence of a small amount...

The 5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphine-Mn(III) chloride (F20TPPMn(III)Cl) catalyzed oxidation of 2,4,6-tri-tert-butylphenol (TTBP) by pentafluoroiodosylbenzene (C6F5IO) in dichloromethane (CH2Cl2) and acetonitrile (CH3CN) medium was studied. The reactive intermediates of ...

SummaryBis(N-maleimidomethyl)ether-hemoglobin (HbBME) is a well known derivative of hemoglobin obtained by reaction with bis(N-maleimidomethyl)ether, which forms an intra-chain bond in each of the β subunit of the protein. Previous cristallographic determinations suggest that this chemical modi...

The dispersion of the depolarization ratio of oxidation and spin-marker of oxyhemoglobin-bis(N-maleimidomethyl)ether and oxyhemoglobin at high Cl− concentration (1 M) have been examined for different pH values in the neutral and alkaline regions. The oxidation marker line at 1375 cm−1 shows no p...

The action of many antimicrobial agents is dependent upon their ability to interact strongly with biological membranes. As part of a study of the surface activity of these types of compounds, the properties of the cyclic decapeptides gramicidin S and tyrocidine A were examined. Both molecules we...

Laser desorption ionization (LDI)/laser ablation (LA) time-of-flight mass spectrometry (TOFMS) studies are performed via back-illumination on thin silver films deposited with gramicidin S, a cyclic decapeptide (1141 Da). Experimental results indicate an electronic excitation mechanism at low las...

To investigate the mechanism of interaction of gramicidin S-like antimicrobial peptides with biological membranes, a series of five decameric cyclic cationic β-sheet-β-turn peptides with all possible combinations of aromatic D-amino acids, Cyclo(Val-Lys-Leu-D-Ar1-Pro-Val-Lys-Leu-D-Ar2-Pro) (Ar...

Lactosylated gramicidin-containing lipid nanoparticles (Lac-GLN) were developed for delivery of anti-microRNA-155 (anti-miR-155) to hepatocellular carcinoma (HCC) cells. MiR-155 is an oncomiR frequently elevated in HCC. The Lac-GLN formulation contained N-lactobionyl-dioleoyl phosphatidylethanol...

The inhibition of the gramicidin S-biosynthesis and the thioester formation activities of the multienzyme GS 2 by L-Phe-CMK, a substrate analogue of L-phenylalanine, were investigated. L-Phe-CMK inhibits irreversibly the activation of proline, valine, ornithine and leucine with about the same ve...

The synthesis of novel gramicidin S analogues having additional functionalities in the turn region by employing a biomimetic approach is described. The preservation of β-sheet character in all analogues was established by NMR and the biological activity was evaluated.

For an initial study of potentially surface-structural self-organising systems of biological significance by scanning tunnelling microscopy (STM), gramicidin S, a pseudocentrosymmetric cyclodecapeptide with antibiotic properties, was chosen as prototype, recognising its structure as having both ...

Various NADH models with the following characteristics were studied and compared with previously reported models: (1) use of (S)-phenylalaninol as chiral auxiliary; (2) orientation in or out of the plane of the amide carbonyl. Despite the occurrence of apparently similar characteristics, they ga...

The RRKM calculation and bonding evolution theory analysis coupled with quantum theory of atoms in molecules have been used to investigate kinetics and molecular mechanism of gas phase thermal decomposition of methyl benzoylformate. The pressure-dependent rate coefficients, by applying different...

The present work signifies the spectroscopic study (FTIR and FT-Raman) of the chosen compounds 2-Hydroxy-5-Nitropyridine (2H5NP) and 2-Chloro-5-Nitropyridine (2Cl5NP). Density Functional Theory (DFT) is implemented for the calculation of the molecular geometries, normal modes of vibrations, and ...

The reaction of p-nitrobenzaldehyde (1a) with S-ethyl thioacrylate (2) catalyzed by chalcogenide-TiCl4 gave a mixture of Baylis–Hillman adduct 4a and syn- and anti-2-(chloromethyl)-3-hydroxy-3-(p-nitrophenyl)propanethioates 5a in the ratio of 4:syn-5:anti-5=5:65:30. The crude product obtained f...

Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzole acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, ...

A simple and sensitive method for determination of phosphoric acid triesters at trace levels in human plasma sample is described. In this work, solid-phase microextraction (SPME) is employed as a sample preparation procedure for extraction and pre-concentration of alkyl and aryl phosphates follo...

Presently, the acid-base equilibria of indicators fixed in surfactant micelles are described thoroughly. In contrast, analogous studies with polyelectrolytes are few in number. As a result, though the interactions of polyelectrolytes with dyes in aqueous solution have been studied for a long tim...