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Bifunctional Pt/WO3/zirconium phosphate catalyzes the liquid-phase hydrogenolysis of glycerol in aqueous medium. 1H NMR spectroscopy (solvent suppression pulse program) is employed to monitor this reaction. Propanediols (1,3 + 1,2-PDO) formed...

Pt/W/SBA-15 catalysts (with Pt-loading = 0.5–4 wt% and W-loading = 1 wt%) prepared by the sequential impregnation method were evaluated for selective C–O cleavage of erythritol and glycerol in an aqueous medium. The Pt and W particles dispersed on SBA-15 approached close proximity at higher Pt loadings and afforded synergistic enhancement in C–O hydrogenolysis activity/selectivity. 1,4-Butanediol yields of 30.9% (at 190 °C, 50 bar H2 and 24 h) and 1,3-propanediol yields of 34.4% (at 190 °C, 50 bar H2 and 12 h of reaction) were obtained over these catalysts. Pt nanoparticles (facilitating dissociative H2 adsorption and spillover) and W (present as acidic oligomeric WOx species; activating and coordinating the polyol via 1°-OH group) worked in tandem for the selective hydrogenolysis of polyols yielding terminal diols of industrial demand.

The present study was performed to detect the presence of contaminating microorganisms in two commonly available herbal samples (Centella asiatica and Aloe vera) collected from different areas of Dhaka city, Bangladesh and to assess their antibacterial activity. Out of twenty samples (having ten samples of each categories) studied; the range of total viable bacterial count was approximately 10 3 to 10 8 cfu/g. Presence of Staphylococcus aureus was found in all the samples, followed by Klebsiella spp. in 15 samples, Pseudomonas spp. in 14 samples, Bacillus spp. in 12 samples, Escherichia coli in 9 samples and Vibrio spp. in 7 samples. Salmonella spp. was detected in neither of the sample. 17 samples showed a high fungal load up to 10 7 cfu/g. Antibacterial activity of C. asiatica samples was demonstrated against eight laboratory isolates. Only four C. asiatica samples showed activity against Klebsiella spp. On the contrary, Aloe vera samples (12-14) showed antibacterial activity only against Staphylococcus spp.

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