STEADY-STATE AND TIME-RESOLVED FLUORESCENCE OF 2-AMINOACRIDONE SUGAR-DERIVATIVES

The fluorescence properties of 2-aminoacridone (2-AMAC) and some polys accharide derivatives have been studied in the steady state and with t ime-correlated single-photon counting. 2-AMAC in methanol has an absor ption maximum at 425 nm and a fluorescence emission maximum at 530 nm. The absorption spectrum shows a sufficiently broad tail for satisfact ory excitation by the light from an argon ion laser (488 nm). Lifetime decay analysis shows that the fluorescence lifetime of the aminoacrid one moiety is not changed significantly by the addition of a sugar cha in, or by the length or structure of that chain. 2-AMAC exhibits a flu orescence decay that may be fitted to a single exponential in both met hanol (t approximate to 12 ns) and water (t approximate to 10 ns); in an equal mixture of the solvents the behaviour is best described by a sum of two exponential terms. We have also shown that the absorbance o f a complex mixture of 2-AMAC tagged glycans is directly proportional to their fluorescence emission at 525 nm. These results have confirmed our previous studies that 2-AMAC is a useful and non-selective fluore scent tag in the analysis of polysaccharide chains.