Antioxidants as Molecular Probes: Structurally Novel Dihydro-m-Terphenyls as Turn-On Fluorescence Chemodosimeters for Biologically Relevant Oxidants

Abstract

<jats:p>One interesting aspect of antioxidant organic molecules is their use as probes for the detection and quantitation of biologically relevant reactive oxidant species (ROS). In this context, a small library of dihydroterphenyl derivatives has been synthesised and studied as fluorescent chemodosimeters for detecting reactive oxygen species and hypochlorite. The fluorescence quantum yields of these molecules are negligible, while the corresponding aromatized compounds formed upon oxidation show moderate to high native fluorescence, depending on their structures. The fluorescence signal is quickly developed in the presence of trace amounts of the probe and the analytes in acetonitrile media at room temperature, with good analytical figures. ROS detection in aqueous media required incubation at 37 °C in the presence of horseradish peroxidase, and was applied to glucose quantitation by coupling glucose oxidation by O2 to fluorescence detection of H2O2. The mild reaction conditions and sensitive fluorescent response lead us to propose dihydroterphenyls with an embedded anthranilate moiety as chemosensors/chemodosimeters for ROS detection.</jats:p>

Enantioseparation and antioxidant activity of novel diarylpyrazoline derivatives

“…Dihydrobenzene derivatives become aromatic upon dehydrogenation, gaining stability. Therefore, they may show antioxidant behavior, for instance, for a library of dihydro‐m‐terphenyl derivatives, which were shown to be useful probes for detecting biologically relevant reactive oxidant species (ROS) 1 . For this reason, we considered of interest the study of the radical scavenging properties of compound 3 .…”

“…Therefore, they may show antioxidant behavior, for instance, for a library of dihydro-m-terphenyl derivatives, which were shown to be useful probes for detecting biologically relevant reactive oxidant species (ROS). 1 For this reason, we considered of interest the study of the radical scavenging properties of compound 3. We chose the DPPH method based on the change of color associated with the oxidation of the stable 2,2-diphenyl-1-picrylhydrazyl free radical.…”

“…Partially saturated aromatic systems are potentially interesting as antioxidants. In particular, dihydro derivatives of teraryl systems have been successfully employed for sensing biologically relevant oxidant species via their dehydrogenation to a fluorescent, fully aromatic species 1 . Pyrazoline, the dihydro derivative of pyrazole, is the structural basis of a wide range of compounds with biological activities 2 such as antimicrobial, 3,4 anti‐inflammatory, 3,5 analgesic, 3,5 anticonvulsant, 3,6 antiparkinsonian, 5 hypoglycemic, 3 neuroprotective, 3,7 antidepressant, 3–7 and anticancer 8,9 …”

Oxidative Stress and Antioxidants—A Critical Review on In Vitro Antioxidant Assays

“…(e) The interpretation of antioxidant assay results mainly focuses on the antioxidant-oxidant reactions and related kinetics; however, they often ignore the chromophore/luminescent interactions with the probe, which can cause interferences in the results [ 151 ].…”