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 troubling problems in biotechnology, pharmaceutical industries and amyloid-re-lated disorders. METHODS: In the present study, the inhibitory effects of some carbohydrates (alginate, β-cyclodextrin and trehalose) on the formation of nano-globular aggregates from normal (HSA) and glycated (GHSA) human serum albumin were studied; when the formation of aggregates was induced by the simultaneous heating and addition of dithiotheritol. For the investigations, the biophysical methods of UV-vis spectrophotometry, circular dichroism spectroscopy, transmission electron microscopy and tensiometry were employed. RESULTS: The effect of inhibitory mechanism of these inhibitors on the aggregation of HSA and GHSA was expressed and compared together. CONCLUSION: The results showed that the nucleus formation step of the aggregation process of HSA and GHSA was different in the presence of alginate (compared to β-cyclodextrin and trehalose). The inhibition efficiencies of the carbohydrates on the aggregate formation of HSA and GHSA were different, arising from the differences in the hydrophobicities of HSA and GHSA, and also, the differences between HSA- and GHSA-carbohydrate interactions

Novel method for determination of trace amounts of citalopram in tablets by fast fourier continuous cyclic voltammetry at au microelectrode in flowing solutions

In this work, fast Fourier transform continuous cyclic voltammetric technique for the monitoring of ultra trace amounts of citalopram in a flow-injection system has been presented. The potential waveform, consisting of the potential steps for cleaning, stripping and potential ramp, was continuously applied on an Au disk microelectrode (with a 12.5 µm in radius). The proposed detection method has some advantages, the greatest of which are as follows: first, it is no more necessary to remove oxygen from the analyte solution and second, this is a very fast and appropriate technique for determination of the drug compound in a wide variety of chromatographic analysis methods. The method was linear over the concentration range of 7 - 116 pg mL-1 (r = 0.9960) with a limit of detection and quantitation 2.3 and 7 pg mL-1, respectively. The method has the requisite accuracy, sensitivity, precision and selectivity to assay citalopram in tablets. The influences of pH of eluent, accumulation potential, sweep rate, and accumulation time on the determination of the citalopram were considered. The proposed method was applied to the determination of citalopram in a pharmaceutical preparation

Inhibitory effects of β-cyclodextrin and trehalose on nanofibril and AGE formation during glycation of human serum albumin

The effects of β-cyclodextrin (β-CyD) and trehalose on glycation of human serum albumin (HSA) were studied. These additives reduced AGEs and nanofibril formation of HSA under in vitro glycation conditions and improved its helical structure. These were accomplished through direct interactions of them with HSA and alterations in solute-protein interactions