Effects of solvent environment on the spectroscopic properties of tylosin, an experimental and theoretical approach

Tylosin is a commonly used antibiotic in animal medicine. However, it remains unclear how tylosin impacts the broader ecosystem once the host animal has excreted it. One of the main concerns is that it can lead to the development of antibiotic resistance. Therefore, there exists a need to develop systems that remove tylosin from the environment. Utilizing UV irradiation to destroy pathogens is one technique often deployed by scientists and engineers. However, for light-based techniques to be efficient, it is necessary to understand the spectral properties of the material being removed. Steady-state spectroscopy and density functional theory were used to analyze the electronic transitions of tylosin responsible for its strong absorbance in the mid-UV region. It was observed that the absorbance peak of tylosin stems from two transitions in the conjugated region of the molecule. Moreover, these transitions stem from an electronegative region of the molecule, which would allow them to be manipulated by changing solvent polarity. Finally, a polariton model has been proposed, which can be used to initiate the photodegradation of tylosin without the need for direct irradiation of the molecule with UV-B light.