Inhibitory effects of some carbohydrates on nano-globular aggregation of both normal and glycated albumin

Background: Protein aggregation is one of the important, common and troublingproblems in biotechnology, pharmaceutical industries and amyloid-re-lated disorders

Methods: In the present study, the inhibitory effects of some carbohydrates [alginate,beta -cyclodextrin and trehalose] on the formation of nano-globular aggregates fromnormal [HSA] and glycated [GHSA] human serum albumin were studied; when theformation of aggregates was induced by the simultaneous heating and addition ofdithiotheritol. For the investigations, the biophysical methods of UV-vis spectrophotometry,circular dichroism spectroscopy, transmission electron microscopy andtensiometry were employed

Results: The effect of inhibitory mechanism of these inhibitors on the aggregation ofHSA and GHSA was expressed and compared together

Conclusion: The results showed that the nucleus formation step of the aggregationprocess of HSA and GHSA was different in the presence of alginate [compared tobeta -cyclodextrin and trehalose]. The inhibition efficiencies of the carbohydrates on the aggregateformation of HSA and GHSA were different, arising from the differences inthe hydrophobicities of HSA and GHSA, and also, the differences between HSA-andGHSA-carbohydrate interactions

Amperometric determination of ascorbic acid in pharmaceutical formulations by a reduced graphene oxide-cobalt hexacyanoferrate nanocomposite

Investigation of the redox properties of drugs and their determination are performed by electrochemical techniques. Data obtained from electrochemical techniques are often correlated with molecular structure and pharmacological activity of drugs. In this regard, different modified electrodes were applied as sensors for quantification of different drugs. A nanocomposite of reduced graphene oxide-cobalt hexacyanoferrate was synthesized by a simple precipitation route. Scanning electron microscopy revealed that the nanocomposite comprised nanoparticles of cobalt hexacyanoferrate attached to the reduced graphene oxide nanosheets. A nanocomposite-modified carbon paste electrode was then fabricated. It represented prominent activity toward the electrocatalytic oxidation of ascorbic acid, and the kinetics of the electrooxidation process was evaluated. Finally, an amperometric method was developed for the quantification of ascorbic acid in different pharmaceutical formulations

[Development of non-enzymatic amperometric biosensor for the determination of cysteine and acetyl cysteine]

Extensive researches exist in the recent years about attractive properties of nanoparticles and their applicability in design of the biosensors. In this area, development of simple and reliable biosensors for the determination of sulfhydryl compound is pertinent. In this trial, an enzyme-less amperometric biosensor was designed for the detection of cysteine and N-acetyl-L-cysteine. Nanoparticles of iron [III] oxide core-cobalt hexacyanoferrate shell were synthesized and employed as a signal transducer in the amperometric biosensor. The nanoparticles represented a good redox behavior and represented an efficient catalytic activity toward the oxidation of the substrates. Amperometric signals of the biosensor were successfully recorded for quantification of the substrates and the biosensor was successfully employed for the analysis of real samples or determination in blood serum and urine