Sulfonated Charcoal,a Mild and Efficient Reagent for the Tetrahydropyranylation of Alcohols and Phenols

Sulfonated charcoal has been demonstradted to be very effective and mild catalyst for the tetrahydropyranylation of alcohols and phenols.     

Montmorillonite KSF,a Mild and Efficient Catalyst for Benzodithiepination of Carbonyl Compounds

A mild and efficient procedure for the protection of carbonyl compounds as 1,5-dihydro-3H-2,4-benzodithiepines in high yields is described by using a readily available and inexpensive KSF clay catalyst.     

Can mobile shapes of fractals cause rate enhancement?

The notion of mobile shapes of a fractal object has been introduced to explain rate enhancements beyond the limits set by three-dimensional diffusion control. Allowing for mobilities of fractal shapes in the practical range, theoretical simulations for a model system show several hundred-fold variation in rates. The results of the analysis can have wide implications in understanding several biochemical as well as physical and chemical systems.     

Extraction and separation of silver using triphenylphosphine sulphide

Silver compounds are used in pharmaceutical and ayurvedic medicines. A method is proposed for the extraction separation of silver from Cu, Cd, Zn, Ni, Pt (IV) and Au (III) from nitrate solution using triphenylphosphine sulphide as an extractant. The recovery of silver is tested both volumetrically and/or by ICP-AES technique.     

Total synthesis of the novel seco-prezizaane sesquiterpenoid (+)-1S-minwanenone

The first total synthesis of (+)-1S-minwanenone, an archetypical seco-prezizaane sesquiterpene, has been accomplished from a readily available chiral endo-tricyclic synthon following a flexible strategy.     

Separation of gold from Cu, Pt, Pd, Ni, Zn, Cd and Hg using triphenylarsine oxide as an extractant

A method is developed for extraction of gold(III) (75–300 g) from hydrochloric acid solution with triphenylarsine oxide dissolved in toluene as extradant. Gold(III) is determined spectrophotometrically with stannous chloride. The extraction is quantitative from 1.5–1.9M hydrochloric acid with 0.25% triphenylarsine oxide and an equilibration period of 30s. The method permits separation of gold(III) from Cu(II), Pt(IV), Pd(II), Ni(II), Zn(II), Cd(II) and Hg(II) and its spectrophotometric determination in ayurvedic medicines. The recovery and relative standard deviation obtained are >99.0% and <1.0%.     

Simultaneous high-performance liquid chromatographic determination of pioglitazone and metformin in pharmaceutical-dosage form

A simple, rapid, and precise method is developed for the quantitative simultaneous determination of metformin and pioglitazone in a combined pharmaceutical-dosage form. Separation is achieved with a Zorbax XDB C(18), 15-cm analytical column using buffer-acetonitrile (66:34, v/v) of pH 7.1, adjusted with orthophosphoric acid as the mobile phase. The buffer used in the mobile phase contains 10mM disodium hydrogen phosphate and 5mM sodium dodecyl sulphate in double-distilled water. The instrumental settings are flow rate of 1 mL/min, column temperature at 40 degrees C, and detector wavelength of 226 nm. The internal standard method is used for the quantitation of the ingredients of this combination. Methylparaben is used as an internal standard. The method is validated and shown to be linear for metformin and pioglitazone. The correlation coefficients for metformin and pioglitazone are 0.9991 and 0.9999, respectively. The relative standard deviations for six replicate measurements in two sets of each drug in the tablets are always less than 2%.