Analysis of fluorescence spectra of synthetic and isolated lignins

Daniela Đikanović1, Jelena Bogdanović1, Aleksandar Kalauzi1, Milorad Jeremić2, Ksenija Radotić1

1Centre for Multidisciplinary Studies of the University of Belgrade,2Faculty of Physical Chemistry, University of Belgrade

Lignin is one of the main constitutive polymers of the plant cell wall that protects plant cell from different kinds of stress (chemical, biological, physical). We analyzed fluorescence emission spectra of lignin isolated from Picea omorika needles, using multicomponent decomposition of lignin emission band in blue-green part of the spectrum. We compared these data to data obtained with a synthetic lignin-like polymer. Decomposition of a family of fluorescence spectra, obtained by lignin excitation at different wavelengths, starting from excitation maximum at 365 nm, with 5 nm step, resulted in four or five band components. The assignment of the observed emission bands to defined structures is difficult, since the system investigated is very complex. Matematical analysis as well as comparison of the excitation and emission spectra of isolated lignin and lignin model-compound is utilized to understand the real nature of the fluorophores.

Email: danielle@ibiss.bg.ac.yu

Address: Centre for Multidisciplinary Studiesof the University of Belgrade,, Despota Stefana 142, 11000 Beograd, Serbia;