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Bioinspired tailoring of fluorogenic thiol responsive antioxidant precursors to protect cells against H2O2-induced DNA damage
- Source :
- Free Radical Biology and Medicine. 160:540-551
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- Natural antioxidants, like phenolic acids, possess a unique chemical space that can protect cellular components from oxidative stress. However, their polar carboxylic acid chemotype reduces full intracellular antioxidant potential due to limited diffusion through biological membranes. Here, we have designed and developed a new generation of hydrophobic turn-on fluorescent antioxidant precursors that upon penetration of the cell membrane, reveal a more polar and more potent antioxidant core and simultaneously become fluorescent allowing their intracellular tracking. Their activation is stimulated by polarity alteration by sensing intracellular signals and specifically biothiols. In our design, the carboxylic group of phenolic acids that originally restricts cell entrance is derivatized and conjugated through Copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) to a coumarin derivative that its fluorescence properties are quenched with a biothiol activatable element. This more hydrophobic precursor readily penetrates cell membrane and once inside the cell the antioxidant core is revealed upon sensing glutathione, its fluorescence is restored in a turn-on manner and the generation of a more polar character traps the molecule inside the cell. This turn-on fluorescent antioxidant precursor that can be applied to phenolic acids, was developed for rosmarinic acid and the conjugate was named as RCG. The selectivity and responsiveness of RCG towards the most abundant biothiols was monitored through a variety of biophysical techniques including UV-Vis, fluorescence and NMR spectroscopy. The electrochemical behavior and free radical scavenging capacity of the precursor RCG and the active compound (RC) was evaluated and compared with the parent compound (rosmarinic acid) through cyclic voltammetry and EPR spectroscopy, respectively. The stability of the newly synthesized bioactive conjugate RC was found significantly higher than the parent rosmarinic acid when exposed to oxygen. Cell uptake experiments were conducted and revealed the internalization of RCG. The degree of intracellular DNA protection offered by RCG and its active drug (RC) on exposure to H2O2 was also evaluated in Jurkat cells.
- Subjects :
- 0301 basic medicine
chemistry.chemical_classification
Antioxidant
Carboxylic acid
medicine.medical_treatment
Rosmarinic acid
Biological membrane
Glutathione
Biochemistry
Cell membrane
03 medical and health sciences
chemistry.chemical_compound
030104 developmental biology
0302 clinical medicine
medicine.anatomical_structure
chemistry
Physiology (medical)
medicine
Biophysics
Thiol
030217 neurology & neurosurgery
Intracellular
Subjects
Details
- ISSN :
- 08915849
- Volume :
- 160
- Database :
- OpenAIRE
- Journal :
- Free Radical Biology and Medicine
- Accession number :
- edsair.doi...........1d6067f3b4b4c76ea7d4ff1c4af5595c