Fluorescence Properties And Singlet Oxygen Quantum Yield Of Parietin, An Anthraquinone Derivative Isolated From Teleoschistes Flavicans

LAURA RAQUEL COMINI; F.E. MORAN VIEYRA; R.A. MIGNONE; SUSANA C. NÚÑEZ MONTOYA; JULIANA MARIONI; JOSE LUIS CABRERA; CLUADIO BORSARELLI

Córdoba

Congreso; 16th INTERNATIONAL CONGRESS ON PHOTOBIOLOGY; 2014

International Union of Photobiology

Since several years anthraquinone (AQs) derivatives have been thoroughly studied in relation to their photosensitizing properties in photodynamic reactions [1,2]. On the basis of this, some of them showed good antibacterial and antiviral effects, by photosensitization of reactive oxygen species (ROS) such as superoxide anion (O2.¯), hydroxyl radical (OH.) and singlet molecular oxygen (1O2), with subsequent oxidative damage [3, 4]. This time we report the purification and identification of parietin (PTN), an AQ isolated from vegetal specie: Teleoschistes flavicans (SW) Norm. (Telochistaceae). In addition, the spectroscopic properties of the pigment in CHCl3 as solvent, indicate that PTN absorbs blue light and shows almost 3% of fluorescence efficiency with a remarkable Stokes shift of 70 nm and non-exponential fluorescence decay, suggesting a possible excited-state tautomeric keto-enol or charge-transfer intramolecular equilibrium. Additionally, we performed time-resolved detection of singlet oxygen luminescence at 1270 nm by 355 nm laser pulsed excitation (7 ns fwhm) and by using phenalen-1-one as reference compound the singlet molecular oxygen quantum yield. F  0.8 was determined, indicating that this AQs derivative shows good photosensitizing properties, which can be associated with its potential photodynamic activity .