Toxicity prediction of anti tuberculosis active molecules

Abstract
The aim of the work was to understand the toxicity, physically significant descriptors and pharmaceutically relevant properties of some imidazoles obtained from the open sources that may found to be active against tuberculosis. At present five azoles were modeled for the prediction and calculation of descriptors that were carried out by means of computational approach [1].
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Lifetimes of active molecules. II

Experimental data on the atomic cracking of propyl radicals and on the deuterization of methyl radicals are compared with some theoretical calculations. With the aid of some assumptions concerning intramolecular energy transfer in the dissociating molecules involved in these and other reactions and concerning the corresponding activated complexes, data on a number of free radical reactions are correlated

Biologically active molecules from marine microalgae

Diatoms are unicellular photosynthetic microalgae responsible for approximately 40% of marine primary productivity. This algal class has traditionally been regarded as providing the bulk of the food that sustains the marine food chain to top consumers and important fisheries. However, this beneficial role has recently been questioned on the basis of laboratory and field studies showing that although dominant zooplankton grazers such as copepods feed extensively on diatoms, the hatching success of eggs thus produced is seriously impaired. Short chain polyunsaturated aldehydes, such as 2,4,7-decatrienal and 2,4-decadienal, were correlated to the antiproliferative effect of diatoms on copepod reproduction. After establishing a method of analysis, the aldehyde profile of some ecologically relevant species of marine diatoms was assessed. The results showed that the production of aldehydes is species-specific. Detailed chemical analysis revealed the presence of fatty acid derivatives other than aldehydes such as hydroxyacids, ketoacids, oxoacids and epoxyalcohols, increasing the complexity of a chemical defence of diatoms mediated only by aldehydes. All these compounds belong to a class of compounds called oxylipins, that are oxygenated compounds biosynthesized from fatty acids by oxygenasecatalyzed oxygenation. Marine diatoms are able to produce the major antiproliferative oxylipins by a novel oxygenase-dependent oxidation of C16 fatty acids hexadecatrienoic acid (16:3 (w-4) and hexadecatetrenoic acid (16:4 (w-1), and C2o eicosapentaenoic acid (20:5 (w-3). This process is triggered by lypolitic acyl hydrolase activity, that feeds the downstream lipoxygenase pathway. The ecological meaning of the oxylipin pathway in the diatom-copepod interactions is discussed, showing that attention should move from single compounds to complex biochemical process. The deleterious effect on copepod reproduction could be due to a biochemical process such as the generation of an high oxidative potential, rather than only by aldehydes or other secondary oxygenated products, that when present can co-occur to produce the final effect

Redox-Active Molecules as Therapeutic Agents

Oxidative stress and altered redox signaling have been described in a plethora of pathological conditions. Redox-active molecules can thus potentially be used to modulate the etiology/progression of such diseases. Recent advances in molecular biology and pharmacology have strengthened this area of research by providing novel mechanistic insights. This book compiles a collection of 13 articles, covering a range of topics from in vitro studies to clinical research, focused on the potential therapeutic effects of either natural or synthetic compounds, applicable to different redox-related diseases

Electrochemical detection methods for biologically-active molecules

Pulsed Amperometric Detection (PAD) has proven to be applicable to the determination of a number of organic compounds. One difficulty has been calibration of PAD for quantitative analysis over a wide concentration range. By pairing PAD in series with Conductivity Detection (CD), a much wider linear calibration range was found for carbohydrates and amino acids. Both compound groups were separated via anion-exchange chromatography and detected at Au electrodes;In an attempt to decrease amino acid detection limits, phenylthiohydantoin and methylthiohydantoin derivatives were examined. PAD was found to be more sensitive to these derivatives than the free amino acids. DC amperometry was also applicable to the thiohydantoin derivatives, with no instability or sensitivity loss with time observed. Detection limits as low as two picomoles were determined. Employment of a commercially available C-18 column allowed separation of nearly all amino acids using gradient elution liquid chromatography;Improvement in detection of underivatized amino acids was made by applying Pulsed Coulometric Detection (PCD) and Indirect Coulometric Adsorption Detection (ICAD). Both could be used following separation on anion-exchange columns. PCD was coupled with a glass reference electrode to allow anion-exchange separation of amino acids using gradient elution, and baseline perturbation during the gradient was minimal. Up to 20 amino acids were separated in less than one hour

Redox-Active Molecules for Novel Nonvolatile Memory Applications

The continuous complementary metal‐oxide‐semiconductor (CMOS) scaling is reaching fundamental limits imposed by the heat dissipation and short‐channel effects, which will finally stop the increase of integration density and the MOSFET performance predicted by Moore’s law. Molecular technology has been aggressively pursued for decades due to its potential impact on future micro‐/nanoelectronics. Molecules, especially redox‐active molecules, have become attractive due to their intrinsic redox behavior, which provides an excellent basis for low‐power, high‐density, and high‐reliability nonvolatile memory applications. This chapter briefly reviews the development of molecular electronics in the application of nonvolatile memory. From the mechanical motion of molecules in the Langmuir‐Blodgett film to new families of redox‐active molecules, memory devices involving hybrid molecular technology have shown advantageous potential in fast speed, low‐power, and high‐density nonvolatile memory and will lead to promising on‐chip memory as well as future portable electronics applications

Kinetics of Surfactant Adsorption at Fluid/Fluid Interfaces: Non-ionic Surfactants

We present a model treating the kinetics of adsorption of soluble surface-active molecules at the interface between an aqueous solution and another fluid phase. The model accounts for both the diffusive transport inside the solution and the kinetics taking place at the interface using a free-energy formulation. In addition, it offers a general method of calculating dynamic surface tensions. Non-ionic surfactants are shown, in general, to undergo a diffusion-limited adsorption, in accord with experimental findings.Comment: 6 pages, 3 figures, see also cond-mat/960814