A Highly Sensitive Spectrophotometric Assay of Bleomycins Based on the Fading Reaction of Some Halofluorescein Dyes

Abstract

AbstractIn weak acidic medium, anticancer antibiotics bleomycin A5 (BLMA5) and bleomycin A2 (BLMA2) can react with halofluorescein dyes such as erythrosin (Ery), eosin Y (EY), eosin B (EB) and rose bengal (RB) by virtue of electrostatic attraction and hydrophobic force to form the ion‐association complexes, which can result in the fading reactions of four halofluorescein dyes. The maximum fading wavelengths of these four dyes were located at 527 nm for Ery, 515 nm for EY, 517 nm for EB and 546 nm for RB, respectively. The decrements of absorbance ((A) were directly proportional to the concentrations of bleomycin in a certain range. A new method for the determination of bleomycins anticancer drugs based on fading reactions of halofluorescein dyes has been developed. The method was not only highly sensitive but also simple and rapid. The molar absorptivities (ε) ranged from 1.5×105 to 7.5×105 L·mol−1·cm−1. It was applied to determination of the bleomycins in human serum, urine and rabbit serum samples. In this work, the spectral properties and the optimum reaction conditions were investigated. The structure of ion‐association complexes and the reaction mechanism were discussed.