The UVB photolysis of L-tyrosine yields species with fluorescence and absorption spectra that are very similar to those of humic substances. By potentiometric measurements, chemical modeling and the application of NMR, mass spectrometry and laser flash photolysis, itwas possible to get insights into the structural and chemical properties of the compounds derived by the L-tyrosine phototransformation. The photolytic process follows aromaticring hydroxylation and dimerization. The latter is presumably linkedwith the photoinduced generation of tyrosyl (phenoxy-type) radicals, which have a marked tendency to dimerize and possibly oligomerize. Interestingly, photoinduced transformation gives compounds with protogenic and complexation capabilities similar to those of the humic substances that occur naturally in surface waters. This finding substantiates a new and potentially important abiotic (photolytic) pathway for the formation of humic compounds in surface-water environments.

Properties of the humic-like material arising from the photo-transformation of L-tyrosine

BERTO, Silvia;CHIAVAZZA, ENRICO;DANIELE, Pier Giuseppe;MINELLA, Marco;ISAIA, MARCO;VIONE, Davide Vittorio
2016

Abstract

The UVB photolysis of L-tyrosine yields species with fluorescence and absorption spectra that are very similar to those of humic substances. By potentiometric measurements, chemical modeling and the application of NMR, mass spectrometry and laser flash photolysis, itwas possible to get insights into the structural and chemical properties of the compounds derived by the L-tyrosine phototransformation. The photolytic process follows aromaticring hydroxylation and dimerization. The latter is presumably linkedwith the photoinduced generation of tyrosyl (phenoxy-type) radicals, which have a marked tendency to dimerize and possibly oligomerize. Interestingly, photoinduced transformation gives compounds with protogenic and complexation capabilities similar to those of the humic substances that occur naturally in surface waters. This finding substantiates a new and potentially important abiotic (photolytic) pathway for the formation of humic compounds in surface-water environments.
545-546
434
444
http://www.sciencedirect.com/science/article/pii/S0048969715312031
Photochemistry, Protogenic sites, Ligands for metals, Aromatic amino acids, Surface waters
Berto, Silvia; Laurentiis, Elisa De; Tota, Tiziana; Chiavazza, Enrico; Daniele, Pier Giuseppe; Minella, Marco; Isaia, Marco; Brigante, Marcello; Vione, Davide Vittorio
File in questo prodotto:
File Dimensione Formato  
photo_tyrOH_AperTO.pdf

Accesso aperto con embargo fino al 31/12/2017

Descrizione: Articolo principale
Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 961.15 kB
Formato Adobe PDF
961.15 kB Adobe PDF Visualizza/Apri
2016_tyrosine photo-transformation_Science of the Total Environment.pdf

Accesso riservato

Descrizione: Articolo principale
Tipo di file: PDF EDITORIALE
Dimensione 1.17 MB
Formato Adobe PDF
1.17 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1558778
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 25
social impact