[Chemical and biological properties of a fluorescence derivative of gentamycin]

By reaction with 4-phenylspiro[furan-2(3H),1'-phthalan]-3,3'-dione a fluorescing gentamycin derivative was produced which is characterized by the following properties: High fluorescence intensity in UV light, which enables simple and sensitive determination up to 10(-9) M. In this way it is possible to determine the localization of this substance in tissues, cells and body fluids. When favorably stored, the derivative is chemically stable. At pH 8 and storage at +5 degrees C in the dark for 27 days the substance loses only 5% of its original fluorescence. In comparison with the nonsubstituted gentamyzin the derivative has a twofold higher binding capacity to serum albumin. The antimicrobial properties are retained; the range of antimicrobial effects is similar to that of gentamycin.