Novel TLC Densitometric Method for Quantification Of Solasodine in Various Solanum Species, Market Samples and Formulations

This paper describes a novel TLC densitometric method for the determination of solasodine in various Solanum species (Family Solanaceae). Solasodine does not give absorption in UV range. Hence, ion pair complex of solasodine and acid dye was spotted on TLC plates. A developing solvent with an organic acid ensured in situ color development of the complex which could be successfully quantified at 461 nm. Linearity was found to be in the range of 79.2–495 ng spot⁻¹ with correlation coefficient of 0.995. This method is reproducible, specific, eliminates post derivatization steps and the problem of background interference. The method was completely validated and applied to determine solasodine content in various herb samples, herb extract and their formulations. Accuracy of the method was found to be 98.54 ± 2.8%. No matrix interference was observed.     

Hydrodynamic Dispersion and Lamb Surfaces in Darcy Flow

Transport in Porous Media - Transport processes such as the dispersion and mixing of solutes are governed by the interplay of advection and diffusion, where advection acts to organise fluid...     

An Asymptotic-Numerical Method for a Class of Weakly Coupled System of Singularly Perturbed Convection-Diffusion Equations

A weakly coupled convection dominated system of m-equations is analyzed. A higher order accurate asymptotic-numerical method is presented. The solutions of convection dominated problem are known to exhibit multi-scale character. There exist narrow region across the boundary of the domain where the solution exhibit steep gradient. This region is termed as boundary layer region and the solution of problem is said to have a boundary layer. Outside of this region, the solution of system behaves smoothly. To capture this multi-scale nature given system is factorized into two explicit systems. The degenerate system of initial value problems (IVPs), obtained by setting ??=?0, corresponds to the smooth solution, which lies outside of boundary layers. For solution inside boundary layers, a system of boundary value problems (BVPs) is obtained using stretching transformation. Regardless of this simple factorization, solutions of these systems preserve the key features of the given coupled system. Runge–Kutta method is used to solve the degenerate system of IVPs, whereas the system of BVPs is solved analytically. Stability and consistency of the proposed method is established. A uniform convergence of higher order is obtained. Possible extension to differential difference equations are also brought to attention. A comparative study of the present method with some state of art existing numerical schemes is carried out by means of several test problems. The results so obtained demonstrate the effectiveness and potential of present approach.     

Bio-Assisted Preparation of Nano Zinc Oxide and Its Behavior Towards Textile Azo Pollutants

High Energy Chemistry - Recent reports on nanoparticles rise significantly as they possess numerous applications in medical, material science, optics, and bioscience etc. Nanoparticles show unique...     

Benzyl isobornyl amines: a simple and practical class of NMR discriminating agents for effective chiral recognition of acids

The design and synthesis of a few simple N-benzyl derivatives of isobornyl amine is presented. The derivatives have been assessed as chiral solvating agents for effective discrimination of the signals of some acids in NMR analysis. The single crystal X-ray analysis of the salts of (R)-mandelic acid with two of the title derivatives help to understand the supramolecular interactions and assign the induced chemical shifts in ¹H NMR analysis. The title derivative is found to be suitable for quantitative determination of the enantiomeric excess of unknown enantiomeric purity as well as being efficient in resolving racemic mandelic acid.     

Addition reactions of allyl stannanes to an indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt

The addition of organometallic reagents to the 13b‐position of the indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt 4 is described. Reaction of 4 with tetraallyl tin in 2‐methoxyethanol gave the allyl adduct 7 in moderate yield. Further elaboration of 7 yielded the pentacyclic benzylidene alcohols 13 and 14 . Structure elucidation of the compounds prepared was achieved by a combination of ¹H nmr spec troscopy and X‐ray crystallography.     

Synthesis of Functionalized Benzopyrans via Intramolecular 1,3-Dipolar Cycloaddition of Nitrile Oxides

Various functionalized benzopyran derivatives have been synthesized in good yields by a sequence of reactions viz. intramolecular cyclization of nitrile oxides, reductive cleavage, and acetylation.     

Development and validation of a sensitive ELISA for quantitation of Grastim (rhG-CSF) in rat plasma: Application to a pharmacokinetic study

Grastim is bacterially produced recombinant counterpart of human granulocyte colony stimulating factor (G-CSF). It has biological activity similar to that of endogenous G-CSF. In the present work a sensitive, accurate, precise and enzyme-linked immunosorbent assay (ELISA) for the quantitation of G-CSF in rat plasma was developed and validated. The ELISA method employed a technique in which anti-human-G-CSF was adsorbed onto 96-well maxisorp plates and used to capture the G-CSF in rat plasma samples. The captured G-CSF was then detected using streptavidin-HRP amplification system. Absolute recovery was >90% from rat plasma. The validation includes assessments of method accuracy and precision, range of reliable response, lower limit of quantitation (LLOQ), storage stability (30 days) in rat plasma and assay specificity. The standard curve for G-CSF was linear (R2 > 0.996) in the concentration range 4.88-625 pg/mL. The LLOQ was established at 4.88 pg/mL. The inter- and intra-day precisions in the measurement of quality control (QC) samples, 15, 250 and 500 pg/mL, were in the range 3.00-8.66% relative standard deviation (RSD) and 1.03-4.69% RSD, respectively. Accuracy in the measurement of QC samples was in the range 87.28-110.79% of the nominal values. The assay shows dilutional linearity and specificity. Stability of G-CSF was established for 30 days at -80 degrees C and through three freeze-thaw cycles. The validated assay was successfully employed for the assessment of pharmacokinetic disposition of G-CSF in rats.