Chemistry Articles

Purpose:
The purpose of this study was to prepare several 1,3-thaizolidin-4-ones bearing variously substituted diaryl ring at C-2 and N-3 positions and evaluate them for their anti-YFV activity.

Methods:
Several 1,3-thaizolidin-4-ones were prepared by reacting substituted benzaldehyde with equimolar amount of an appropriate substituted aromatic amine in the presence of an excess of mercaptoacetic acid in toluene utilizing microwave irradiation. The synthesized compounds were also evaluated for their inhibitory effects on the replication of YFV in green monkey kidney (Vero) cells (ATCC CCL81), by means of a cytopathic effect reduction assay. Results: The compound DS1 emerged as the most potent anti-YFV agent with EC50 of 6.9 µM and CC50 more than 100 µM making it more potent than ribavirin. Conclusion: 2,3-diaryl-1,3-thiazolidin-4-ones possess anti-YFV potency.

Abstract: PURPOSE: A series of N-Arylhydrazone derivatives of mefenamic acid (a known non-steroidal anti-inflammatory drug) were synthesized in order to obtain new compounds with potential analgesic and anti-inflammatory activity. METHODS: The structures of all synthesized compounds were confirmed by means of infrared, proton magnetic resonance and mass spectroscopy. All compounds were evaluated for their analgesic and anti-inflammatory activities by abdominal constriction test (writhing test) and carrageenan-induced rat paw edema test respectively. RESULTS: Most of the synthesized compounds induced significant reduction in the writhing response when compared to control. Among them, compounds 11, 12, 15, 16, 19, 20, and 21 were significantly more potent than mefenamic acid in the writhing test.

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Impetus for the design of simple strategies for site-specific incorporation of biochemical and biophysical probes in RNAs is fueled by the increasing realization that the role of RNA and RNA-protein interactions is pervasive in various cellular and developmental processes. Advances in solid-phase oligonucleotide synthesis of small RNAs have facilitated the site-specific introduction of functional groups that lend themselves to subsequent chemical modification. For instance, a 2' amino group in an RNA oligonucleotide can be converted to a thiol (by treatment with an activated ester and a reducing agent), which in turn can be modified to incorporate a probe of choice. However, for large RNAs that cannot be synthesized chemically, a commonly employed approach has been to include guanosine-5'-monothiophosphate (GMPS) in an in vitro transcription reaction to enable enzymatic synthesis of an RNA transcript whose 5' end contains the monothiophosphate group.

Optimization of the fermentation medium for maximum alkaline protease production was carried out using a new strain, Bacillus Sp. PE-11. METHODS: The carbon source (glucose), the nitrogen source (peptone) and salt solution were selected to optimize. A 23 full factorial composite experimental design and response surface methodology were used in the design of experiments and in the analysis of results. This procedure limited the number of actual experiments performed while allowing for possible interactions between the three components. RESULTS AND DISCUSSION: The optimum values for the tested variables for the maximum alkaline protease production were; glucose 7.798 (g/L), peptone 9.548 (g/L) and salt solution 8.757%. The maximum alkaline protease production was 4,98,123 PU/L. This method was efficient; o­nly 20 experiments were necessary to assess these conditions, and model adequacy was very satisfactory, as the coefficient of determination was 0.941.

The reversible acetylation of -amino groups of lysine residues clustered near the amino terminus of nucleosomal histones by histone deacetylases (HDACs) and histone acetyl transferases (HATs) has a significant influence o­n the chromatin superstructure and o­n the interactions of DNA with transcriptional regulators. Modification of the level of histone acetylation and its consequences have received enormous interest in recent years, and increasing evidence supports their importance for basic cellular functions such as DNA replication, transcription, differentiation, and apoptosis. Aberrant histone acetylation emerging from HAT mutations or abnormal recruitment of HDACs has been correlated with carcinogenesis. Inappropriate recruitment of HDACs provides a common molecular mechanism by which genes necessary for proper differentiation or growth suppression can be silenced, leading to excessive proliferation.

In an extraordinary series of papers for their time, in the 1940s, 1950s, and 1960s, the Australian coordination chemist, Frances P. Dwyer, and a series of very talented collaborators including Alan Sargeson, David Buckingham, Harold Goodwin, and Bryce Bosnich developed the synthetic chemistry of polypyridyl complexes of ruthenium and osmium.

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Spectroscopic investigations of 2,2,6,6-tetramethylpiperidide (LiTMP) and the conformationally locked (but otherwise isostructural) lithium 2,2,4,6,6-pentamethylpiperidide (LiPMP) are described. 6Li and 15N NMR spectroscopic studies of [6Li]LiPMP and [6Li,15N]LiPMP in hydrocarbon solution reveal a mixture comprised of four isomeric cyclic tetramers (C4h, D2h, C2v, and Cs) and o­ne isomeric cyclic trimer (C3h). These results are compared with the aggregation numbers and conformational preferences of lithium 2,2,6,6-tetramethylpiperidide (LiTMP) in the solid state studied by Lappert and co-workers. In the presence of N,N,N¢,N¢-tetramethylethylenediamine (TMEDA), [6Li,15N]LiPMP affords monomer and open dimer to the exclusion of solvated cyclic dimer. The open dimer undergoes a degenerate intramolecular rearrangement.

Flemish chemist Jan Van Helmont was as much alchemist and magician as scientific pioneer. Is belief in magic compatible with a commitment to scientific knowledge? Although the answer to this question might seem simple to many contemporary scientists, it was a subject of much debate in the 17th century. Indeed, for o­ne of the forefathers of modern chemistry, the line separating magic and science was not as wide as some might think.


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The cytochrome P450 enzymes belong to a superfamily of heme-containing mono-oxygenases that are involved in the metabolism of numerous endogenous and exogenous substrates. The ethanol-inducible cytochrome P450 2E1 catalyzes the oxidation of a large number of drugs and hepatotoxic xenobiotics, including halogenated alkanes, acetaminophen, nitrosamines, benzene, and styrene. Evidence from homology models of P450 2E1 and studies in which a conserved threonine residue in the I helix of several different P450s was mutated to an alanine points to a role for this residue in the orientation of substrate in the P450 active site and as a possible proton donor in acid-base reactions. Site-specific mutation of this threonine residue (T303A) in P450 2E1 has allowed for comparisons between wild-type P450 2E1 and the mutant enzyme.

A wide range of biomineralization and templating methods exist for organizing inorganic materials at a wide range of length-scales. Here, we show that crystallographic control of the inorganic nanostructures is possible using synthetic biomolecular templates comprised of anionic DNA and cationic membranes,4 which self-assemble into a multilamellar structure where a periodic o­ne-dimensional (1D) lattice of parallel DNA chains is confined between stacked two-dimensional (2D) lipid sheets. We have organized Cd2+ ions within the interhelical pores between DNA strands and subsequently reacted them with H2S to form CdS nanorods of controllable widths and crystallographic orientation. The strong electrostatic interactions align the templated CdS (002) polar planes parallel to the negatively charged sugar-phosphate DNA backbone, which indicates that molecular details of the DNA molecule are imprinted o­nto the inorganic crystal structure.