Kinetics and binding studies on the reaction of cyanopropyl(aquo)cobaloxime with CT-DNA and amines

2628-2631The ligand substitution reactions of cyanopropyl (aquo) cobaloxime have been studied with various amines such as Methylamine, ethylamine, butylamine, pentylamine, hexylamine, cyclopropylamine, cyclohexylamine and cyclope ntylamine, as entering nucleophiles. The entering nucleophile displaces the molecule trans to the cyanopropyl group to form the six-coordinated complex, [CNCH2CH2 CH2Co(DH)2L]. The rate constants have been determined by varying the pH and concentration of the ligand under pseudo first order conditions. Equilibrium constants have been determined as a function of pH, for the binding of amines to [CNCH2CH2 CH2Co(DH)2L]. Study shows that the entering nucleophile participates in the transition state, and hence, SN1 mechanism is proposed. Antimicrobial activity of cyanopropyl (aquo)cobaloxime on E coli has been studied. The interaction of cyanopropyl(aquo) cobaloxime with CT DNA has been studied spectrophotometrically and binding constant has been calculated

Bioremediation of toxic metal ions using biomass of <i style="">Aspergillus fumigatus</i> from fermentative waste

139-143Dried, nonliving, granulated biomass of Aspergillus fumigatus from fermentation industry was used for the removal of Cd2+, Co2+, Cu2+ and Ni2+ from solutions. Sorption studies showed sequestration (70-90%) of Cd2+ from solutions (0.1-4 mM). However, with increase in concentration, Cd2+ sorption efficiency decreased due to saturation of the biosorbent. Cu2+ binds most efficiently (72%) to the biosorbent followed by Cd2+ (61%), Co2+ (49%) and Ni2+ (37%). Metal removal from solutions containing a mixture of metal ions (Cd2+, Cu2+, Co2+, and Ni2+), which reflects the features of the polluted wastewaters and industrial effluents, was also efficient (90%) at lower concentrations (0.1 mM each). At higher concentrations (5 mM to 25 mM), Cu2+ removal was predominant (>70%) over other ions. The biosorbent was reusuable up to 5 cycles with a 50% loss of initial Cd2+ binding capacity. However, a significant loss of Cd2+ binding capacity was observed when biosorbent was immobilized in polyvinyl foam. Infrared spectra of the biosorbent preparation showed the involvement of alcohol/amine (OH/NH2) and CH-OH functional groups in metal binding. The present studies suggest that fungal biomass, a waste from fermentative industry, has the potential for removal/recovery of toxic metal ions from aqueous solutions