Estudo teórico de filtros orgânicos UV: avobenzona, octisalato, homosalato, octocrileno e bemotrizinol

Abstract

Ultraviolet (UV) radiation is one of the main risk factors for living organisms, especially humans. Continuous exposure to this type of radiation is associated with several harmful effects, ranging from immediate reactions, such as burns and inflammation, to long-term consequences, such as premature aging and the development of skin cancer. The use of sunscreens has established itself as one of the most effective and widely used strategies to mitigate these risks, as these compounds act by absorbing or deflecting radiation be- fore it reaches essential biological structures. Among the most widely used organic filters in the cosmetics industry are avobenzone, homosalate, octisalate, octocrylene, and be- motrizinol, recognized for their effectiveness in protecting against different ranges of UV radiation. Despite their popularity, some of these compounds have limitations related to photoinstability, which can compromise the efficiency of sun protection. This challenge has motivated studies that seek to understand the mechanisms of photodegradation and propose strategies to increase the stability and performance of these filters. In addi- tion, the presence of these compounds in aquatic and terrestrial environments has raised concerns about environmental contamination, as they can affect marine organisms. Con- sidering these aspects, the field of simulation and computational modeling has played a fundamental role in understanding the processes of absorption, excitation, and photoche- mical degradation of organic UV filters. Through theoretical investigations of electronic and structural properties, such approaches not only elucidate mechanisms underlying UV protection but also aid in predicting more stable, efficient, and environmentally safe alter- native molecules. In this context, the present work investigated the ground and excited states, both in singlet form, of the five organic filters mentioned, considering their absorp- tion ranges in the gas phase and in polar protic media (water, methanol, and ethanol), with the aim of evaluating the influence of the solvent on spectroscopic behavior. To this end, computational chemistry methods based on DFT and TD-DFT were employed to examine electronic, energetic, and structural aspects.