Photophysical properties of hydroxyphenyl benzazoles and their applications as fluorescent probes to study local environment in DNA, protein and lipid

Abstract

Fluorescence techniques have drawn increasing attention because they provide crucial information about molecular interactions in protein-ligand systems beyond that obtained by other methods. The advantage of fluorescence spectroscopy stems from the fact that the majority of molecules in biological systems do not exhibit fluorescence, making fluorescent probes useful with high sensitivity. Also, the fluorescence emission is highly sensitive to the local environment, providing a valuable tool to investigate the nature of binding sites in macromolecules. In this review, we discuss some of the important applications of a class of molecules that have been used as fluorescent probes in a variety of studies. Hydroxyphenyl benzazoles (HBXs) show distinct spectroscopic features that make them suitable probes for the study of certain biological mechanisms in DNA, protein and lipid. In particular, the complex photophysics of 2-(2'-hydroxyphenyl)benzoxazole (HBO) and the distinguished fluorescence signatures of its different tautomeric forms make this molecule a useful probe in several applications. Among these are probing the DNA local environment, study of the flexibility and specificity of protein-binding sites, and detecting the heterogeneity and ionization ability of the head groups of different lipidic phases. The spectroscopy of HBX molecules and some of their chemically modified structures is also reviewed.

Calculations of molecular properties of 2-(2'-hydroxyphenyl)benzoxazole by semi-empirical tight-binding methods

“…HBO has been studied for several decades to elucidate microscopic mechanism of this photochemical reaction and tested as possible luminescent substance for a number of applications. HBO has been studied in the solid state [1,2], incorporated into polymer chains [3], proteins, lipids, DNA [4] and used as a ligand in complexes with metals [5].…”

Interaction Study between ESIPT Fluorescent Lipophile-Based Benzazoles and BSA

“…10000 cm −1 ) [14,15]. These photophysical features allow these compounds to be applied as pH sensors [16][17][18][19], WOLEDs [20][21][22][23][24][25], optical sensors [26][27][28], bioimaging [29][30][31][32][33][34][35], and lipid probes [36][37][38][39][40].…”