Voltammetric DNA biosensor for the study of mechanism of action of anticancer drug-adriamycin

593-597The interaction of anticancer drug adriamycin with DNA has been studied using voltammetric DNA biosensor. The binding mechanism of adriamycin was elucidated by using differential pulse voltammetry (DPV) at DNA modified glassy carbon fiber electrodes (GCFE). The decrease in guanine oxidation peak current at +0.9 V was used as an indicator for interaction mechanism in acetate buffer (pH 4.5). The studied drug-DNA interaction mechanism at charged electrode surface is similar to the in-vivo DNA-drug complex formation, where DNA is in close contact with charged phospholipid membranes and proteins. Thus, the fabricated biosensor helps in understanding the in-vivo mechanism of action of this anticancer drug

Indirect Electrochemical Analysis of Crocin in Phytochemical Sample

A new electroanalytical method has been developed for the quantitative determination of crocin in a sample of stigmas of saffron (Crocus sativus L.). Crocin is polarographically inactive. However, cysteine in 0.02 M NaCl, pH=5.2±0.01 produces a well defined wave/peak with E1/2/Ep= –0.47/–0.45 V vs. Ag/AgCl. On recording polarograms of a set of solution containing a fixed concentration of cysteine and varying concentrations of crocin under aforesaid experimental conditions a gradual decrease in peak height/diffusion current and a negative shift in peak potential was observed. Thus, indicating cysteine-crocin interaction. Amperometric titration indicated crocin to cysteine ratio of 1:2. The above amperometric titration procedure has been used to determine the concentration of crocin in a sample of saffron. Crystallization process was carried out for the extraction of crocin from dried powder of saffron stigmas. The crystallized crocin was identified by UV-Visible spectrophotometry(at 255 nm and 442 nm) and the quantitative analysis by the developed amperometric method. The concentration of crocin in saffron was found to be 2.13% and purity of isolated crocin 96.81%. The percent recovery varied from 98.56–100.31% and RSD (n=5) of 2.17%.The validation of the proposed procedure for the quantitative assay of crocin was examined via an evaluation of the repeatability, recovery, selectivity and relative standard deviation