The influence of molecular structure features on the aggregation behavior, lipophilicity, pH stability and antifungal activity of Br2-BODIPY photosensitizers

The search for photosensitizers with optimal 1 O 2 generation efficiency, aggregation tendency, pH and photostability, and biocompatibility is an important task, since such compounds can be used as photodynamically active theranostics, providing effective antimicrobial therapy. This paper presents the study results of the lipophilicity, aggregation behavior, pH stability, and antifungal activity of dibromo-substituted BODIPYs containing extended alkyl substituents in the meso -spacer or pyrrole rings, in comparison with alkyl- and meso -unsubstituted analogs. It has been demonstrated that the introduction of extended substituents into the dipyrromethene core alters the preferred biotarget for luminophore localisation in the cell. The influence of structural factors (bromination and alkylation positions) of dibromo-BODIPY photosensitizers on their ability to form dimers in organo-aqueous media was described using DFT analysis. The present study complements our previous works on the search for photosensitizers that can be considered as good candidates for photoinactivation of a large spectrum of microorganisms. • The structure effect on the aggregation, stability and bioactivity of Br 2 -BODIPYs was studied. • The introduction of extended substituents into the dyes core inhibits their aggregation. • The luminophores effectively penetrate to C. albicans cells and inhibit their viability. • The Br 2 -BODIPYs with extended alkyl-substituents are promising PSs for medical applications.