title: Slow solvent relaxation dynamics of nanometer sized reverse micellar systems through tryptophan metabolite, kynurenine.
abstract: Exploration of environmental dynamics using intrinsic biological probe tryptophan is very important; however, it suffers from various difficulties. An alternative probe, kynurenine (KN), has been found to be an efficient probe for the ultrafast dynamics in the biological environment (Goswami et al., [2010] J. Phys. Chem. B., 114, 15236-15243). In the present study, we have investigated the efficacy of KN for the exploration of relatively slower dynamics of biologically relevant environments. A detailed investigation involving UV-Vis, steady-state/time-resolved fluorescence spectroscopy and Förster resonance energy transfer (FRET) studies on KN compared to a well-known solvation probe, H33258, a DNA-minor groove binder in a model nonionic reverse micelle reveals that ultrafast internal conversion associated with the hydrogen-bonding dynamics masks KN to become a dynamical reporter of the immediate environments of the probe.
authors.affiliation: Department of Chemical, Biological & Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata, India.
authors.forename: Surajit
authors.initials: S
authors.lastname: Rakshit
authors.forename: Nirmal
authors.initials: N
authors.lastname: Goswami
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Pal
mesh_terms: D031541:Fluorescence Resonance Energy Transfer; D007737:Kynurenine / Q000737:chemistry*; D008823:Micelles; D053758:Nanoparticles; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D008823:Micelles; D012997:Solvents; D007737:Kynurenine