Synthesis and Application of Seleno- and Telluro-Indolizine Derivatives: Studies of Emission and Suppression of the Fluorescence for Detection of Reactive Oxygen Species

Abstract

The last two decades have seen a remarkable increase in the applications of fluorescent probes in biological processes. In this regard, the desired detection properties of such probes are essential for proper investigation of molecular interactions and for them to be widely used in diagnostic procedures. An efficient way to identify specific pathologies, especially those associated with oxidative processes, is by detection of Reactive Oxygen Species (ROS) and Nitrogen (RNS). Therefore, a number of fluorescent probes based on the emission (on) and suppression (off) of the fluorescence, modulated by photoinduced electron transfer, have been employed in order to detect such species. Chalcogen heavier atoms such as Selenium and Tellurium, when inserted into the chromophoric core, can suppress or inhibit the probe's fluorescence emisson (off) and when they are oxidized, the fluorescence emission of the molecule is restored (on). Thus, this project aims towards the preparation of different Seleno- and Telluro-indolizine derivatives to studies cell labeling in oxidative processes. The choice of the indolizinic core as a chromophoric group is based on its strong fluorescence in the UV-visible range and its great photochemical properties. Subsequently, the obtained chromophores may also be anchored to the surface of metal nanoparticles such as gold (Au), silver (Ag), platinum (Pt) and/or palladium (Pd), in order to transport them to the required site of action.These proposals are based on the recently collaboration with a group of researchers from the Universidade Nova de Lisboa (Profs. Drs. Espiño Carlos Lodeiro and Jose Luis Capelo) which has extensive experience in the fluorescent sensors area and Dr. Lionel Gamarra of Brain Research Center, Albert Einstein Hospital.