Silver Nanoparticles Supported on Chitosan as a Green and Robust Heterogeneous Catalyst for Direct Synthesis of Nitrogen Heterocyclic Compounds under Green Conditions

The catalytic efficiency of silver nanoparticles supported on chitosan as a green, robust, and efficient nanocatalyst for the direct synthesis of biologically active compounds, such as: imidazole derivatives as well as pyrazine scaffolds through multi-component reactions strategy, have been demonstrated. In this work, imidazole derivatives were achieved via pseudo four-component reactions by utilization of benzaldehydes, benzils, anilines, and ammonium acetate under solvent-free conditions. Moreover, pyrazine scaffolds were synthesized through a three-component reaction of phenylenediamine derivatives, isocyanides and various ketones in water. The main advantages of this protocol are the  reusability of the catalyst, operational simplicity, mild reaction conditions, and high-yielding. Copyright © 2019 BCREC Group. All rights reserve

Non-essential metals (Cd & Pb) accumulation and elimination in liver tissue of juvenile milkfish, after sublethal exposure

412-417Present study consists the bioaccumulation of cadmium and lead in young juvenile Milkfish liver (Chanos chanos). It is carried out after exposure to three sublethal concentration of each pollutants (on 1/20, 1/10 and 1/5 LC50 of 96-h LC50) for acute time 12, 24 and 96 hour and subchronic time 7, 14 and 21 days. Cadmium and lead accumulation in liver increased with exposure periods and concentration of pollutants. Compared with controls, the uptake of cadmium is much higher than that of lead. Accumulation factors showed an increase with the exposure period and an inverse relationship between the accumulation factor and exposure concentration for lead. Elimination of these two pollutants was investigated after 30 days depuration time. During the depuration phase, cadmium and lead concentration decreased