Fungal infections represent a significant public health issue, especially due to the rising number of immunocompromised patients and the growing incidence of drug-resistant fungal strains. Although traditional antifungal treatments are effective, they often suffer from drawbacks such as toxicity, a narrow range of activity, and the potential for resistance. Consequently, there is a crucial need to discover new antifungal agents with innovative mechanisms of action. In this regard, benzo[a]phenoxazines have surfaced as promising candidates.

Benzo[a]phenoxazines are a class of heterocyclic compounds known for their diverse biological activities, including antimicrobial, anticancer, and antiviral properties. Their unique structure, characterized by a fused aromatic system, imparts distinctive electronic and photophysical properties, making them attractive for various biomedical applications.

Given the interest of our research team in this type of compounds, in this work we present the synthesis, photophysical characterization, and evaluation of the potential antifungal activity of a series of benzo[a]phenoxazines. The UV-Vis absorption and fluorescence data revealed notable strong absorbance and significant fluorescence emission superior than 650 nm in water, indicative of their potential applicability in fluorescent labelling. Furthermore, the antifungal activity of the synthesized benzo[a]phenoxazines was assessed against Saccharomyces cerevisiae and the results were promising and provide clues to direct further studies.