Treatment of 3-0-mycarosylerythronolide B (V) with glacial acetic acid gave 3-0-mycarosyl-8,9-anhydroerythronolide B 6,9-hemiketal (VI) together with 3-0-mycarosylerythronolide B 6,9; 9,11-spiroketal (VII). Fluorination of VI with trifluoromethyl hypofluorite (CF3OF) gave a mixture of 3-0-mycaro...

Synthetic studies are reported in the erythromycin analogue area. Reaction of trifluoromethyl hypofluorite (CF3OF) with 8,9-anhydroerythronolide A 6,9-hemiketal (1) or 8,9-anhydroerythronolide B 6,9-hemiketal (2) afforded, as major product, (8S)-8-fluoroerythronolide A 6,9;9,ll-spiroketal (3) or...

Camptothecin and four of its 10,11-methylenedioxy analogues were examined for their activity against the pathogenic protozoan Leishmania donovani in vitro. The methylenedioxy analogues were 36- to 180-fold more potent than the parent camptothecin, possessing IC50 values ranging from 160 to 32 nM...

Several new TOP1-targeting agents were prepared using as an intermediate the N,N,N-trimethyl quaternary ammonium salt 2 of ARC-111. Direct displacement of the quaternary ammonium group with hydroxide, cyclopropylamine, imidazole, 1H-1,2,3-triazole, alkylethylenediamines, ethanolamine, and polyhy...

Potent antitumor activity exhibited by 20-S-camptothecin (CPT) and numerous derivatives is known to be lost upon opening of the α-hydroxy-lactone ring of these drugs, hydrolyzable at neutral and basic pH. To quantify in `real time' the lactone hydrolysis reaction in CPTs under physiologica...

We describe the effect strongly influencing the biological activity of some camptothecin (CPT) drugs, the inhibitors of DNA topoisomerase I (topo I), namely, the formation of J-type aggregates in an aqueous buffer solution. These aggregates were built up under certain dilution conditions of the ...

The topoisomerase I inhibitor camptothecin and its analogs have potent activity against a wide range of solid tumors and several hematologic malignancies. Previous studies with these compounds using the MTT metabolic inhibition assay have shown significant cytotoxicity against lymphocytes from p...

The objective of this study was to develop and characterize a biodegradable drug-loaded nerve guide for peripheral nerve regeneration. Sabeluzole, a nerve growth agent, was selected as model compound. Four biodegradable polymers were selected for this study: a copolymer of polylactic acid and po...

There is growing evidence that cytoskeletal instability of neuronal cells is an important step towards tangle formation and subsequent functional disconnection in the AD brain. Sabeluzole, a new drug in clinical trials for Alzheimer's disease (AD), has been shown to slow down the clinical p...

The charge transfer (CT) interactions involving the substituted pyridinium ion are of a remarkable biological interest. In particular the pyridinium ions having substituents in position 3 of the heterocyclic ring constitute models for the study of similar, more complex structures.In this paper s...

Lateral lithiation of ethyl 4-acetyl-5-methyl-3-isoxazolyl carboxylate, a functionalized isoxazole AMPA analog, occurs cleanly at the C-5 methyl group with 5,5-dimethyl-1,3-dioxanyl as a directing group. The 4-acetyl isoxazole derivatives were transformed selectively by a modified Willgerodt-Kin...

This article is the first to report the direct, one-step synthesis of molybdenum blue (MB) in solid state, via application of cyclic voltammetry. Electrochemical synthesis of MB was carried out in a three-electrode cell in 1.0 M sulfuric acid and at the appropriate amount of sodium molybdate dih...

This work aims to develop novel ceramic ultrafiltration membranes made from purified natural Moroccan clays. Two raw clays namely Clay A (smooth aspect) and Clay B (rough aspect) were purified via physicochemical treatment. Chemical and mineralogical characterizations demonstrated that obtained ...

Toxicity and intermediates of C.I Direct Red 28 (DR 28) azo dye was investigated through decolorization and mineralization of DR 28 azo dye in a sequential upflow anaerobic sludge blanket reactor (UASB)/continuous stirred tank reactor (CSTR) system. System performance was determined by monitorin...

A novel dinuclear copper(II) complex 2 bearing double μ2-oxo bridges has been obtained by in situ CuII ion catalysis and complexation with the H2O2 oxidant of C.I. Disperse Yellow 79 (1), where a new dianionic ligand is in situ formed having an additional phenolic group and it coordinates with ...

During the direct acid-leaching process of vanadium extraction from black shale, the participation of fluoride ions greatly improves the leaching efficiency of vanadium. Its enhanced effect is influenced by the sulfuric acid concentration, amount of added fluoride, leaching temperature, and leac...

Rapid pyrolysis at high temperatures is a promising process to obtain black SiO2 nanoparticles, which can be applied, for their characteristic color, in different areas, such as cosmetics, graphite, paints, ceramics and polymer industry (thermoplastics, rubber and tires). In this work, the physi...

Non-noble metal (NNM) catalysts have recently attracted intensive interest for their high catalytic performance towards oxygen reduction reaction (ORR) at low cost. Herein, a novel NNM catalyst was synthesized by the simple pyrolysis of carbon black, urea and a Fe-containing precursor, which exh...

The direct quenching of low-carbon steels after thermomechanical processing on hot strip mills is able to produce both strong and tough coiled plate without the need for subsequent tempering. The process is energy and time efficient with relatively low emissions when compared to conventional reh...

The advanced oxidation processes (AOPs), which can produce oxidizing hydroxyl radicals (OH) have been proven to be an efficient method for degradation of the dyes. In this work, the decolorization of a dye solution containing C.I. Basic Yellow 28 (BY28) was performed by photoelectro-Fenton (PEF)...