Microwave-assisted oxidative coupling of thiols using polystyrene supported bromoderivatives of 2-oxazolidone

Polymer-supported reagents have become popular in synthetic organic chemistry over the past decades. But the kinetics of polymer-supported reactions is slow compared to solution phase synthesis because of the poor diffusion of the reactants through the macromolecular polymer matrix. This difficulty can be reduced to a great extent by performing polymer-supported reactions under microwave (MW) conditions. The present work is focussed on the design and development of an innovative, powerful, MW stable and recyclable polymeric reagent prepared by attaching bromoderivative of 2-oxazolidone into the macromolecular matrix of polystyrene. 3% cross-linked polystyrene was prepared by free radical aqueous suspension polymerization technique using tetra ethylene glycol diacrylate as the cross-linking agent and the resulting beads were functionalized by chloromethylation followed by reaction with 2-oxazolidone. Bromine functionality is introduced into the polymer by treating with bromine in carbon tetrachloride. The synthetic utility of the prepared polymeric reagent was demonstrated by the oxidative coupling of thiols to disulfides under MW irradiation. No over oxidation was observed in this protocol and the utilization of polystyrene support simplifies work up and product isolation. The synthesised polymeric reagent displayed good cyclic stability up to five cycles without any substantial decrease in bromine content and satisfactory storage stability under normal laboratory condition. Moreover this may be the first report that uses MW energy for the oxidation of thiols to disulfides using polymer-supported reagents. [Formula: see text]

Genomic DNA Extraction Protocol for Artemisia Annua L. Without Using Liquid Nitrogen and Phenol

Artemisia annua is an important medicinal plant, used for curing various diseases especially malaria. It secretes verities of secondary metabolites which hinders in the DNA extraction. This investigation describes an efficient DNA extraction protocol for A. annua based upon the Cetyl Trimethyl Ammonium Bromide (CTAB) extraction method without using hazardous chemicals i.e. liquid nitrogen and phenol. The developed protocol is simple, reliable and operative in normal laboratory condition yielding intact DNA having good quantity (502.7 to 1288.5 ng/µl) and quality (A260/280 ratio - 1.82 to 1.85) in two working days. Proper amplification of extracted DNA indicates its suitability for the various molecular biological applications. Int J Appl Sci Biotechnol, Vol 4(4): 448-451

Effects of electromagnetic field on testes and semen characteristicsin male New Zealand white RabbIts

The main objective of the current study was to understand the effect of EMF on testes and semen characteristics in male New Zealand White rabbits under ecological conditions. Rabbits were assigned randomly to 2 treatment groups of 8; EMF and control groups were housed 6 m under high voltage power lines (380 kV) and 500 m away from the power lines for 7 weeks, respectively. Following EMF exposure, blood was withdrawn from all rabbits and 4 rabbits per treatment were euthanized. Remaining rabbits were kept in normal laboratory condition for another 7 weeks for recovery. Decrease in the plasma testosterone concentrations, paired testes, epididimides and the accessory sex gland weights and seminiferous tubule diameters were noted in EMF group. Although ejaculate volume, pH, seminal plasma protein levels and libido were not affected by EMF, the percent sperm head/tail defects, percent progressive motility and sperm concentrations were lower in EMF group. The depression on semen quality was transient and returned to normal by week 7 of recovery period. Therefore, exposure of male animals to EMF may have reversible adverse effect on the reproductive performance