Spectral characteristics and mechanism of chemi luminescence from tryptophan solutions induced by uv irradiation
Slawinski, J.; Elbanowski, M.; Slawinska, D.
Photochemistry and Photobiology 32(2): 253-260
ISSN/ISBN: 0031-8655 Accession: 006459556
The spectral distribution of the chemiluminescence, fluorescence and phosphorescence of tryptophan aqueous solutions irradiated with high and low pressure Hg lamps was measured. The blue emission bands in the region of 380-520 nm observed in the chemi- and photoluminescence, and an absorbance increase at 230 and 330 nm, indicate oxidative degradation of tryptophan leading to the formation of derivatives of N-formylkynurenine, xanthurenic and anthranilic acids. Red emission bands at 630 and 705 nm in the chemiluminescence spectrum, an enhancement of light intensity by D2O and its decrease by NaN3 and DABCO suggest a partial contribution of O2 to the photooxidation and chemiluminescence of tryptophan. The enthalpy of the exergonic reactions, leading to the formation of luminescing products, was calculated to average -270 kJ .cntdot. mol.