Molecular organization of 4-cyano-4′-nonylbiphenyl in a dielectric medium: A statistical analysis

The molecular organization of 4-cyano-4′-nonylbiphenyl (CNBP) in a dielectric medium has been explored using a statistical model based on quantum mechanics and computer simulation. The complete neglect differential overlap (CNDO/2) method has been employed to evaluate the net atomic charge and atomic dipole components at each atomic centre of the molecule. The modified Rayleigh-Schrodinger perturbation theory along with multicentered multipole expansion method has been employed to evaluate the long-range intermolecular interactions, while the 6-exp potential function has been assumed for short-range interactions. The total interaction energies obtained through these computations were used as input to calculate the probability of occurrence of each configuration in a dielectric medium, benzene, at room temperature (300 K) using the MB formula. The various possible geometrical arrangements between a molecular pair during the different modes of interactions have been considered. This provides theoretical support to the experimental observations.     

Reactions of triflate esters and triflamides with an organic neutral super-electron-donor

The bis-pyridinylidene 13 converts aliphatic and aryl triflate esters to the corresponding alcohols and phenols respectively, using DMF as solvent, generally in excellent yields. While the deprotection of aryl triflates has been seen with other reagents and by more than one mechanism, the deprotection of alkyl triflates is a new reaction. Studies with (18)O labelled DMF indicate that the C-O bond stays intact and hence it is the S-O bond that cleaves, underlining that the cleavage results from the extraordinary electron donor capability of 13. Trifluoromethanesulfonamides are converted to the parent amines in like manner, representing the first cleavage of such substrates by a ground-state organic reducing reagent.     

Cholinesterase inhibition activity of Marsilea quadrifolia Linn. an edible leafy vegetable from West Bengal, India

Maesilea quadrifolia Linn. (Marsileaceae) is a leafy vegetable well known in India. The current study aims to explore the phytochemical profile of M. quadrifolia and investigate its anti-cholinesterase potential. The methanol extract of the plant was subjected to qualitative and quantitative phytochemical screening (total alkaloidal content, saponin content and phenol content) and its anti-cholinesterase potential was tested by TLC bioautography and other screening methods using acytylcholinesterase (AChE) and butyrylcholinesterase (BChE). The study revealed that the extract contains various classes of phytoconstituents including steroids, saponins, alkaloids and other polyphenols. Total alkaloid, phenolic and saponin contents were found to be 19.3?mg?g?1 and 158.5?±?1.02?mg?g?1 as gallic acid equivalents and 2.63?mg?g?1 of the extract, respectively. The TLC bioautography method exhibited the inhibition of both enzymes. In a microtiter plate assay, the IC?? values of the extract for AChE and BChE were found to be 51.89?±?0.24?μg?mL?1 and 109.43?±?2.82?μg?mL?1, respectively. These findings suggest that M. quadrifolia is a potential lead as an AChE and BChE inhibitor, which may be useful in the management of Alzheimer's disease.