In search for a probable local solution for Qarasu River problems and based on our prescience about metal ion chelating/reducing ability of tannins which are found in large amount in oak acorns bark, Quercus brantii (Persian oak) acorns bark extract was exploited as reducing/capping agent in silver nanoparticles synthesis. Synthesis was carried out as a single-step method at room temperature, and without consuming any external energy by using these renewable barks. The crystallinity, size and shape of the nanoparticles were characterized by X-ray diffraction and scanning electron microscopy (SEM) respectively. The involvement of phenolic compounds in metal ion reduction was supported by UV-Visible and infrared spectroscopies and by acidity and conductivity measurements. The SEM-based particle size distribution analysis and antimicrobial susceptibility test of oak acorns bark-extract-mediated silver nanoparticles against bacterial effluent were pointed out to the critical proportion of silver salt to the capping/reducing agent. It seems that the bactericidal action depends on the extent to which accumulation of silver nanoparticle (Ag-Np) in bacterial cell surface alters the silver nanoparticle colloidal stability in broth medium.

In this study, saponins were extracted from Panax ginseng root powder. The crude solvent-extracted saponins containing triterpenoid glycosides and terpenes that were identified by TLC techniques. The critical micelle concentrations (CMC) of the saponins were determined by measuring the change in (a) the UV-visible spectrum of iodine due to the micelle-iodine complexation, (b) the absorption intensity of aqueous alpha-lipoic acid due to the micellar solubilization of the drug, and (c) the surface tension due to the abrupt change in the air/liquid interface saturation by surfactants monomers. The development of new absorption peak due to the micelle-iodine complexation, enhancement in the absorbance due to the micelle-solubilized lipoic acid, and displacement of monomer-micelle equilibrium to micelle formation in higher monomer concentration region are some of the physicochemical properties in which CMC could be determined. We found a CMC of 0.009% w/v.

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In the original version of the paper, the corresponding author was listed as Iraj Mesgarzadeh. At the request of the authors, the corresponding author changed to Rahmatollah Rahimi. Dr. Rahimi can be contacted at rahimi_rah@iust.ac.ir.