Synthesis of novel 1,4-disubstituted-1,2,3-triazole semi synthetic analogues of forskolin by click reaction

New 1,4-disubstituted-1,2,3-triazole analogues of forskolin (5a-g, 6a-g) have been prepared by regioselective propargylation at 1-position followed by Cu(I) catalysed cycloaddition of different alkyl azides under the click reaction conditions. An interesting acyl shift in the base catalysed propargylation afforded a new series of 1,4-disubstituted-1,2,3-triazole analogues of forskolin (6a-g). These analogues have potential selective therapeutic applications as antihypertensive, antiglaucoma, antiasthma and antiobesity agents.     

Improvement of Ethanol Production Using <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> by Enhancement of Biomass and Nutrient Supplementation

Optimization of ethanol production through addition of substratum and protein-lipid additives was studied. Oilseed meal extract was used as protein lipid supplement, while rice husk was used as substratum. The effect of oil seed meal extract and rice husk was observed at varying concentration of medium sugar from 8% to 20%. Of the three oil seed meal extracts used, viz. groundnut, safflower, and sunflower, safflower was found to be most efficient. The use of oilseed meal extract at 4% was found to enhance ethanol production by almost 50% and enhanced sugar tolerance from 8% to 16%. A further increase of almost 48% ethanol was observed on addition of 2 g of rice husk per 100 ml of medium. An increase in cell mass with better sugar attenuation was observed. Further optimization was sought through use of sugarcane juice as the sugar source. While 8.9% ethanol yield with 75% sugar attenuation was observed at 20% sucrose concentration, it was found to increase to 12% (v/v) with almost complete utilization of medium sugar when sugarcane juice was used. Cell weight was also observed to increase by 26%.     

Simple and sensitive spectrophotometric method for determination of tricyclic antidepressant imipramine using Fe(III)-SCN<Superscript>−</Superscript> complex

A new simple procedure for the spectrophotometric determination of tricyclic antidepressant drug imipramine is proposed. The method is based on the enhancement of the colour intensity of the Fe(III)-SCN⁻ complex due to the addition of the drug imipramine. The value of molar absorptivity of the Fe(III)-SCN⁻ imipramine complex in terms of the drug lies in the range of (2.77–3.16) × 10³ L/mol cm at the absorption maximum 460 nm. The detection limit of the method was 250 μg/L. The slope, intercept, and correlation co-efficient for the present method were found to be 0.008, 0.005, and 0.998, respectively. The effect of analytical variables on the determination of the drug and the composition of the complex are discussed. The method is applicable to the determination of imipramine in the drug samples.     

Synthesis and characterization of lipid-polymer hybrid nanoparticles with pH-triggered poly(ethylene glycol) shedding

Novel lipid-polymer hybrid nanoparticles are designed with a poly(ethylene glycol) (PEG) coating that is shed in response to a low pH trigger. This allows the nanoparticles to be stable during systemic circulation and at neutral pH, but destabilize and fuse with lipid membranes in acidic environments. The hybrid nanoparticles consist of a poly(lactic-co-glycolic acid) core with a lipid and lipid-PEG monolayer shell. To make the hybrid nanoparticles pH sensitive, a lipid-(succinate)-mPEG conjugate is synthesized to provide a hydrolyzable PEG stealth layer that is shed off the particle surface at low pH. The pH-sensitivity of the nanoparticles is tunable using the molar concentration of the lipid-(succinate)-mPEG incorporated in the lipid shell of the particles. Possible uses of these pH-sensitive nanoparticles include aggregating in acidic tumor microenvironments, escaping acidified endosomes, or aggregating in deep lung tissue for improved inhalation administration.     

A simple synthesis of trisubstituted quinolines through transesterification

An efficient and simple method has been reported for the synthesis of 2,3,4‐trisubstituted quinolines through zwitterion intermediate under reflux condition in presence of sulfuric acid. The formed dicarboxylate subsequently undergoes transesterification in various alcohols with good yields. Most of the synthesized compounds are newly reported characterized by spectroscopic method. J. Heterocyclic Chem., (2011).     

A Harmonic Map of Space-Time

In this paper, we study an n-dimensional space-time (M,g) with Einstein field equation and nondegenerate Ricci tensor. It is shown that taking the Ricci tensor \(\mathit{Ric}=\bar{g}\) as another semi-Riemannian metric on M, the identity map \(i:(M,g)\rightarrow ( M,\bar{g}) \) is a harmonic map. We also obtain a characterization of a vacuum using a differential equation satisfied by the electromagnetic stress tensor on space-time. In addition, we also show that if the Ricci tensor of (M,g) is parallel and the signatures of g and \(\bar{g}\) are same, then the semi-Riemannian manifold \(( M,\bar{g}) \) is an Einstein manifold.     

The Z=Z(t/z)-Type Plane Wave Solutions of the Field Equations of General Relativity in a Plane Symmetric Space-Time

Taub (Ann. Math., 53:472?C490, 1951) has studied plane symmetry in Riemannian space-time by considering empty space-time admitting a three parameter group of motions. In this paper, we have deduced the line element of such a space-time for Z=Z(t/z)-type plane gravitational waves using suitable transformations following the concept of Takeno (Sci. Rep. Inst. Theor. Phys. Hiroshima Univ. 1, 1961), Lal and Ali (Tensor 20:281?C302, 1969). Furthermore it has been shown that the deduced space-time admit plane wave solutions of the field equations of general relativity containing electromagnetic terms. Also we have studied electromagnetic field except gauge transformation with particular cases with respect to ??.     

Non-renormalizable Yukawa interactions and Higgs physics

We explore a scenario in the Standard Model in which dimension-four Yukawa couplings are forbidden by a symmetry, and the Yukawa interactions are dominated by effective dimension-six interactions. In this case, the Higgs interactions to the fermions are enhanced in a large way, whereas its interaction with the gauge bosons remains the same as in the Standard Model. In hadron colliders, Higgs boson production via gluon-gluon fusion increases by a factor of nine. Higgs decay widths to fermion-antifermion pairs also increase by the same factor, whereas the decay widths to photon-photon and γZ are reduced. Current Tevatron exclusion range for the Higgs mass increases to ∼146-222 GeV in our scenario, and new physics must appear at a scale below a TeV.