A General Method to Establish the Relative Efficiency of Different Sonosensitizers to Generate ROS for SDT.

The most common way to demonstrate the reactive oxygen species (ROS)-mediated pathways in photodynamic therapy (PDT) and in sonodynamic therapy (SDT) is the use of specific ROS inhibitors. We present a general method to establish the relative efficiency of different sonosensitizers which produce the same ROS. To demonstrate it, we use peroxides as sonosensitizers which produce singlet molecular oxygen. The method is easily generalized by all types of ROS.

Antioxidant ability of tyrosol and derivative-compounds in the presence of O2(1Δg)-species. Studies of synergistic antioxidant effect with commercial antioxidants.

The exposure of fatty products to environmental light can trigger lipid oxidation in food through a sensitized-photooxidation process, which involves the participation of the species singlet oxygen (O2(1Δg)). Therefore, preservation of food quality represents a subject of great economic interest to the food industry. In this sense, the phenolic compounds are natural antioxidants widely used in food industry. In this contribution we studied the interactions of phenolic derivatives (Phd), tyrosol and tyrosol derived isomers, with O2(1Δg) and their possible protective effect against the oxidative degradation of unsaturated fatty acids and amino acids. Besides, a potential synergistic interaction between Phd and antioxidants used in food industry were investigated. Phd substrates showed properties as antioxidant additives due to their high ability deactivating O2(1Δg) through a physical process and synergistic effect in the presence of commercial antioxidants. Phd presented an antioxidant protective effect toward O2(1Δg)-mediated degradation of methyl linoleate and tryptophan.