Novel cytotoxic constituents of Orthosiphon diffusus

Chemical investigation on Orthosiphon diffusus resulted in the isolation of four relatively rare, novel polychiral furanopyrans, orthodiffenes A-D (1-4) which were characterized from detailed studies of their 1D and 2D NMR spectra. The X-ray crystallographic analysis of orthodiffene A (1) was accomplished. The in vitro cytotoxic activity of orthodiffenes A-C (1-3) was tested against Jurkat and HL-60 cells using camptothecin as a positive control. Orthodiffenes A (1) and B (2) showed comparable activity to camptothecin against HL-60 and Jurkat cells, respectively.     

Studies of some Thermodynamic Properties of Binary Mixtures of Acrylonitrile with Aromatic Ketones at <Emphasis Type="Italic">T</Emphasis>=308.15 K

Densities (ρ), ultrasonic speeds (u), and excess molar volumes (V_m^EV_{\mathrm{m}}^{\mathrm{E}}) of binary mixtures of some aromatic ketones in acrylonitrile have been measured over the entire range of composition at 308.15 K. From these experimental results, parameters such as the isentropic compressibilities K _S , interaction parameter χ ₁₂, Flory parameters, A _i coefficients, standard deviations σ(Y ^E), and molar sound velocities R _m have been estimated. The excess functions were fitted to Redlich-Kister type polynomial equations. The experimental ultrasonic speeds were analyzed in terms of Jacobson’s Free Length Theory (FLT), Schaaff’s Collision Factor Theory (CFT), Nomoto’s relation, and Van Dael’s ideal mixture relation. The intermolecular Free Length L _f, and available volume V _a, have been calculated from the FLT, CFT, and thermoacoustic approaches for binary systems of acetophenone and propiophenone in acrylonitrile at 308.15 K.     

Rational design,synthesis and biological evaluations of amino-noscapine: a high affinity tubulin-binding noscapinoid

Noscapine and its derivatives are important microtubule-interfering agents shown to have potent anti-tumor activity. The binding free energies (ΔG _bind) of noscapinoids computed using linear interaction energy (LIE) method with a surface generalized Born (SGB) continuum solvation model were in agreement with the experimental ΔG _bind with average root mean square error of 0.082 kcal/mol. This LIE–SGB model guided us in designing a novel derivative of noscapine, amino-noscapine [(S)-3-((R)-9-amino-4-methoxy-6-methyl-5,6,7,8-tetrahydro [1, 3] dioxolo[4,5-g]isoquinolin-5-yl)-6,7-dimethoxy isobenzo-furan-1(3H)-one] that has higher tubulin binding activity (predicted ΔG _bind = −6.438 kcal/mol and experimental ΔG _bind = −6.628 kcal/mol) than noscapine, but does not significantly change the total extent of the tubulin subunit/polymer ratio. The modes of interaction of amino-noscapine with the binding pocket of tubulin involved three hydrogen bonds and are distinct compared to noscapine which involved only one hydrogen bond. Also the patterns of non-bonded interactions are albeit different between both the lignads. The ‘blind docking’ approach (docking of ligand with different binding sites of a protein and their evaluations) as well as the reasonable accuracy of calculating ΔG _bind using LIE–SGB model constitutes the first evidence that this class of compounds binds to tubulin at a site overlapping with colchicine-binding site or close to it. Our results revealed that amino-noscapine has better anti-tumor activity than noscapine.     

Parameter estimation,data compression and stochastic noise elimination in robotics: a wavelet domain-based integrated approach

Accurate parameter estimation in presence of stochastic noise is the essential part of almost all control hardware of the plants. However, the optimal design of the control hardware depends on processing power and installed memory. The proposed research investigation focuses on precise parameter estimation from compressed temporal data of error dynamics with exiguous susceptibility to the robot’s controllability. Instead of using Maximum Likelihood estimation (MLE) and Least Squares (LS) estimation in the time domain, the proposed method exploits the recursive wavelet domain’s properties to selectively store the error data coefficients negating the data related to noise. As a result, data compression is achieved. The proposed algorithm may be directly implemented on any scalable “Very Large Scale Integration” (VLSI) circuit due to the recursive implementation. For the evaluation of robustness, dynamic parameter variation is considered. The variation in scalar & vector-valued error is considered to evaluate the performance of the stochastic system. The proposed algorithm implementation is demonstrated experimentally on commercially available Omni Bundle robot.

     

Synthesis and Characterization of Some Bromosubstituted Symmetrical Dipyridyl Ditellurides and X-Ray Structure of 2,2′-Dipyridyl Ditelluride

Organotellurium compounds are proving important precursors for the generation of semiconducting materials. However, synthetic methods for their preparation involve cumbersome manipulations and require controlled experimental conditions. We wish to report a convenient method recently developed for the synthesis of this interesting class of ditellurides. The title compounds were prepared by the reaction of ditelluride anion Te₂ ^2? with 2-bromopyridine (Scheme 1). The ditelluride anion was generated in situ by the reaction of tellurium metal with sodium borohydride in 2-ethoxyethanol. The compounds prepared were characterized by elemental analysis and through various spectroscopic techniques viz; IR, NMR (¹H, ¹³C), mass spectral analysis, crystal structure of 2,2′-dipyridyl ditelluride is reported.

Synthesis and Characterization of Some Bromosubstituted Symmetrical Dipyridyl Ditellurides and X-Ray Structure of 2,2′-Dipyridyl Ditelluride

All authors

K. K. Bhasin, Harish Kumar, Veena Trehan & Jaspreet Singh

https://doi.org/10.1080/10426500590904825

Published online:

01 February 2007

SCHEME 1 Preparation of bromosubstituted symmetrical dipyridyl ditellurides.     

157.

时空分数阶薛定谔方程的指数时间差分方法     

梁霄  Harish BHATT 《数学学报》2019,62(4):663-672

本文针对时空分数阶非线性薛定谔方程,提出了应用Padé近似逼近Mittag-Leffler函数的指数时间差分格式,讨论了提高格式计算效率的方法.本文在具有各种参数的时空分数阶非线性薛定谔方程上进行了数值实验,实验结果说明了所提出方法的准确性、有效性和可靠性.     

158.

Molecule‐Induced Radical Formation (MIRF) Reactions—A Reappraisal     

Lakshmanan Sandhiya  Harish Jangra  Hendrik Zipse 《Angewandte Chemie (International ed. in English)》2020,59(16):6318-6329

Radical chain reactions are commonly initiated through the thermal or photochemical activation of purpose‐built initiators, through photochemical activation of substrates, or through well‐designed redox processes. Where radicals come from in the absence of these initiation strategies is much less obvious and are often assumed to derive from unknown impurities. In this situation, molecule‐induced radical formation (MIRF) reactions should be considered as well‐defined alternative initiation modes. In the most general definition of MIRF reactions, two closed‐shell molecules react to give a radical pair or biradical. The exact nature of this transformation depends on the σ‐ or π‐bonds involved in the MIRF process, and this Minireview specifically focuses on reactions that transform two σ‐bonds into two radicals and a closed‐shell product molecule.     

159.

Esterification in dry Media Using Ferric Perchlorate Adsorbed on Silica Gel     

Anupama Parmar  Jatinder Kaur  Rita Goyal  Baldev Kumar  Harish Kumar 《合成通讯》2013,43(15):2821-2826

Adsorption of Fe(ClO₄)₃(H₂O)₆ onto chromatographic grade silica gel in the presence of alcohol (to be used for esterification) produces a supported reagent, Fe(ClO₄)₃(ROH)₆/SiO₂. This reagent, has been found effective for the rapid and high yield of esters, on grinding in the presence of carboxylic acids using pestle and mortar in the solid state.     

160.

Characterisation and anti-inflammatory evaluation of the inclusion complex of ellagic acid with hydroxypropyl-β-cyclodextrin     

Vipin D. Bulani  Pankaj S. Kothavade  Dnyaneshwar M. Nagmoti  Harish S. Kundaikar  Mariam S. Degani  Archana R. Juvekar 《Journal of inclusion phenomena and macrocyclic chemistry》2015,82(3-4):361-372

     

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时空分数阶薛定谔方程的指数时间差分方法

本文针对时空分数阶非线性薛定谔方程,提出了应用Padé近似逼近Mittag-Leffler函数的指数时间差分格式,讨论了提高格式计算效率的方法.本文在具有各种参数的时空分数阶非线性薛定谔方程上进行了数值实验,实验结果说明了所提出方法的准确性、有效性和可靠性.     

Molecule‐Induced Radical Formation (MIRF) Reactions—A Reappraisal

Radical chain reactions are commonly initiated through the thermal or photochemical activation of purpose‐built initiators, through photochemical activation of substrates, or through well‐designed redox processes. Where radicals come from in the absence of these initiation strategies is much less obvious and are often assumed to derive from unknown impurities. In this situation, molecule‐induced radical formation (MIRF) reactions should be considered as well‐defined alternative initiation modes. In the most general definition of MIRF reactions, two closed‐shell molecules react to give a radical pair or biradical. The exact nature of this transformation depends on the σ‐ or π‐bonds involved in the MIRF process, and this Minireview specifically focuses on reactions that transform two σ‐bonds into two radicals and a closed‐shell product molecule.     

Esterification in dry Media Using Ferric Perchlorate Adsorbed on Silica Gel

Adsorption of Fe(ClO₄)₃(H₂O)₆ onto chromatographic grade silica gel in the presence of alcohol (to be used for esterification) produces a supported reagent, Fe(ClO₄)₃(ROH)₆/SiO₂. This reagent, has been found effective for the rapid and high yield of esters, on grinding in the presence of carboxylic acids using pestle and mortar in the solid state.