Mechanistic Study of the Oxidation of Dehydroalanines by Singlet Oxygen

• Grant number: 23/14111-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2023
• End date: November 30, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Paolo Di Mascio
• Grantee: Davi de Lima de Martin
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Dehydroalanines are present in organisms and are generally found in toxic peptides, antibiotics or modified proteins. The existence and permanence of these species in humans has become a curious fact, since these aminoacids are not used in the synthesis of proteins and their olefin structure is a potential target for oxidants. Therefore, this study aims to study the reactivity of dehydroalanines with singlet oxygen and investigate the consequences and products of these interactions. Reactions will be conducted using N-acyl dehydroalanine derivatives and Type I photosensitizers (riboflavins), aiming the generation of radical photo-products and hydroperoxides, and Type II (rose bengal and methylene blue), aiming reactions with singlet oxygen. The products of these reactions will be analyzed using High Performance Liquid Chromatography coupled to a Mass Spectrometer (HPLC-MS/MS) while a photomultiplier will be used to detect the formation of possible intermediate photo-products through luminescence. The results obtained in the reactions using riboflavin, rose bengal and methylene blue will be compared with each other. The possibility of the formation of singlet oxygen resulting from the decomposition of these photo-products will also be studied. Finally, this work aims to seek a greater understanding of the oxidation mechanisms of dehydroalanines.