RESUMO
A rhodol-based fluorescent probe has been developed as a selective hydrazine chemosensor using levulinate as a recognition site. The rhodol levulinate probe (RL) demonstrated high selectivity and sensitivity toward hydrazine among other molecules. The chromogenic response of RL solution to hydrazine from colorless to pink could be readily observed by the naked eye, while strong fluorescence emission could be monitored upon excitation at 525â¯nm. The detection process occurred via a ring-opening process of the spirolactone initiated by hydrazinolysis, triggering the fluorescence emission with a 53-fold enhancement. The probe rapidly reacted with hydrazine in aqueous medium with the detection limit of 26â¯nM (0.83â¯ppb), lower than the threshold limit value (TLV) of 10â¯ppb suggested by the U.S. Environmental Protection Agency. Furthermore, RL-impregnated paper strips could detect hydrazine vapor. For biological applicability of RL, its membrane-permeable property led to bioimaging of hydrazine in live HepG2 cells by confocal fluorescence microscopy.
Assuntos
Técnicas Biossensoriais/métodos , Fluorescência , Corantes Fluorescentes/química , Hidrazinas/análise , Imagem Molecular/métodos , Espectrometria de Fluorescência/métodos , Xantonas/química , Células Hep G2 , Humanos , Limite de DetecçãoRESUMO
The reaction between the antimalarial drug dihydroartemisinin (DHA) and hemoglobin A (HbA) was investigated in vitro. A fluorescein-tagged artemisinin analog reacted with HbA and fluorescent HbA-drug adducts could be visualized on SDS-PAGE to confirm stable covalent reaction adducts and necessity of the endoperoxide moiety and Fe(II). Mass spectrometric analyses revealed that DHA favourably alkylated protein part rather than heme and the modification site was identified to be at Tyr35 of the beta globin chain.
Assuntos
Antimaláricos/metabolismo , Artemisininas/metabolismo , Hemoglobina A/metabolismo , Alquilação/efeitos dos fármacos , Antimaláricos/química , Antimaláricos/farmacologia , Artemisininas/química , Artemisininas/farmacologia , Sítios de Ligação , Corantes Fluorescentes/química , Hemoglobina A/química , Humanos , Modelos Moleculares , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Espectrometria de Massas em Tandem , Tirosina/metabolismoRESUMO
A rhodol cinnamate fluorescent chemosensor (RC) has been developed for selective detection of hydrazine (N2H4). In aqueous medium, the rhodol-based probe exhibited high selectivity for hydrazine among other molecules. The addition of hydrazine triggered a fluorescence emission with 48-fold enhancement based on hydrazinolysis and a subsequent ring-opening process. The chemical probe also displayed a selective colorimetric response toward N2H4 from colorless solution to pink, readily observed by the naked eye. The detection limit of RC for hydrazine was calculated to be 300nM (9.6ppb). RC is membrane permeable and was successfully demonstrated to detect hydrazine in live HepG2 cells by confocal fluorescence microscopy.