Synthesis and photophysics of benzazole based triazoles with amino acid-derived pendant units. Multiparametric optical sensors for BSA and CT-DNA in solution

• Published in: Journal of molecular liquids 2020-07, Vol.309, p.113092, Article 113092
• Main Authors: Debia, Natalí P., Rodríguez, Juan J.P., da Silveira, Carolina H., Chaves, Otavio A., Iglesias, Bernardo A., Rodembusch, Fabiano S., Lüdtke, Diogo S.
• Format: Article
• Language: English
• Subjects: Amino acid-derived triazole; DNA intercalation; Docking studies; Fluorescent sensor; Protein detection
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.113092

Herein we report the synthesis of a series of amino acid-derived triazoles by an organocatalytic cycloaddition reaction between azides and carbonyl compounds, catalyzed by a simple amine. These compounds present absorption maxima located in the UV-B ascribed to fully spin and symmetry allowed electronic transitions and a main fluorescence emission in the UV-A (~380 nm) with a relatively large Stokes shift (5700 cm−1). No significant solvatochromism was observed in both ground and excited states. Unexpectedly, the benzoxazole derivatives presented much higher fluorescence quantum yield values (40–80%) of compared to the sulfur analogues (3–6%). In addition, the DNA binding assays indicated that these compounds presented strong interaction with CT-DNA, which could be attributed to π-stacking and intermolecular hydrogen-bonding. The interaction of the benzazoles with bovine serum albumin (BSA) was also investigated, where a suppression mechanism was observed. In each case, docking was performed to better understand the observed interactions. [Display omitted] •New series of amino acid-derived triazoles with benzazole pendant unit•High difference between benzoxazole and benzothiazole quantum yields•Strong interaction with CT-DNA•Interaction with BSA showed suppression mechanism