meso-to-meso Sulfide- and Disulf­ide-Bridged Subporphyrin Dimers

Abstract

Treatment of meso-chlorosubporphyrin with controlled equivalents of Na₂S·9H₂O in DMF led to the formation of either meso-to-meso sulfide (S)-bridged dimer 4 or disulfide (SS)-bridged subporphyrin dimer 6. S-bridged dimer 4 displayed a split Soret-like band and a large Stokes shift and became a fully delocalized one-quantum system in the S₁ state, as indicated by femtosecond transient absorption anisotropy measurements and theoretical calculations. Contrastingly, SS-bridged dimer 6 showed a broad but nonsplit Soret-like band, no fluorescence, and very fast S₁ decay with a lifetime of 4 ps, which indicated the presence of a rapid decay channel.

meso-to-meso S-bridged and SS-bridged dimers 4 and 6 are prepared by S_NAr reaction of meso-chlorosubporphyrin. Dimer 4 displays a split Soret-like band and a large Stokes shift, whereas dimer 6 shows weaker interchromophoric interaction. Dimer 4 becomes a one-quantum system in the S₁ state, whereas the S₁ state of 6 displays very fast decay to the ground state with a lifetime of 4 ps.

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One-Pot Synthesis of Biheterocycles Based on Indole and Azole Scaffolds Using Tryptamines and 1,2-Diaza-1,3-dienes as Building Blocks

Abstract

The rapid and expedient assembly of three new classes of biheterocycles of biological interest, viz. indole–imidazoles 4, indole–pyrroles 6 and indole–triazoles 8 was accomplished using different combinations of tryptamines, 1,2-diaza-1,3-dienes, aldehydes, and/or alkynes as readily available building blocks. Twenty-six derivatives were thus prepared in excellent yields (up to 100 %). The products were screened for in-vitro biological studies. Some of these revealed promising anticancer activity against MCF7 and Caco-2 human tumor cell lines.

The incorporation of indole and azole pharmacophores into new biheterocyclic scaffolds as potential anticancer agents was achieved using different combinations of tryptamines, 1.2-diaza-1,3-dienes, aldehydes, and/or alkynes as readily available building blocks.

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The National Academy of Sciences, India (NASI)

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Influence of Nitrogen Levels and Planting Geometry on Sweet Sorghum ( Sorghum bicolor ) Juice Sugar Quality Traits Under Semi-arid Tropical Environment

Abstract

Sweet sorghum (Sorghum bicolor (L.) Moench) is a potential bioenergy crop that produces both food (from grain) and biofuel (from stalk juice). The present investigation undertaken to assess the effect of different plant density and nitrogen levels on juice extraction and sugar quality traits of sweet sorghum grown in postrainy season of 2008–2009. Three planting geometries as main treatments (30 × 15, 45 × 15 and 60 × 15 cm) and four levels of nitrogen (0, 30, 60 and 90 kg ha⁻¹) application levels as sub-plot treatments were assessed in split-plot design. It is found that the combination of relatively lower nitrogen application level (60 kg ha⁻¹) with maximum population density (spacing 45 × 15 cm) are needed for higher sugar and ethanol yields in the farmer fields.

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The National Academy of Sciences, India (NASI)

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Extraction of Nattokinase Enzyme from Bacillus cereus Isolated from Rust

Abstract

Nattokinase (NK) is widely used as the thrombolytic agent due to its low cost as compared to several other thrombolytic agents. In the present study rust samples from iron rod was collected and subjected to isolation process in order to screen the NK production. Based on the morphological, biochemical and molecular characterization, the isolate VITSDVM3 was identified as Bacillus cereus which showed highest similarity to B. cereus strain GY-58. The specific activity was determined by casein hydrolysis assay and found to be 954, 1008, 1168, 1201 U/mg for crude, precipitated, dialysed and purified. The NK bearing clot buster activity was determined further by radial caseinolytic activity followed by fibrin degradation assay which showed 10 and 15 mm respectively. The maximum clot lysis activity was found to be 97.43 %. The stability of the purified enzyme was analysed by various parameters including pH, temperature, surfactants, metal ions and organic solvents. High Performance Liquid Chromatography analysis was performed in order to indentify the retention time. Our preliminary data thus indicated the fibrinolytic effects of NK, and suggesting its potential value as a therapeutic agent and the need for additional studies and clinical trials.

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A Class of Shrinkage Estimators of Scale Parameter of Uniform Distribution Based on K-Record Values

Abstract

In this paper, we have suggested some classes of shrinkage estimators of scale parameter envisaged by Shy and Chacko (Calcutta Stat Assoc Bull 62:143–158, 2010) based on k-record values using uniform distribution. We have shown the superiority of the proposed estimators over Shy and Chacko (Calcutta Stat Assoc Bull 62:143–158, 2010) estimator.

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