[Rubomycin complexing with copper (II)]

Complexing of rubomycin (H2R) with copper ions (II) in aqueous solutions was studied on the basis of fluorimetric and photometric measurements. H2R interacted with Cu (OH)+ to form the complex CuR with the molar extinction coefficient Ek = 4 . 96 . 10(3) and the stability 1g beta k = 5.54 +/- 0.09. The method of determining H2R in biological materials has been developed. It is based on the ability of the copper entering the complex to extinguish fluorexon luminescence in aqueous solutions.