scholarly journals Fluorescence “off” and “on” signalling of esculetin in the presence of copper and thiol: a possible implication in cellular thiol sensing

2018 ◽  
Vol 17 (9) ◽  
pp. 1197-1205 ◽  
Author(s):  
Rupali G. Shinde ◽  
Ayesha A. Khan ◽  
Amit Kunwar ◽  
V. S. Tripathi ◽  
Atanu Barik

The fluorescence intensity of esculetin was drastically reduced in the presence of a copper ion, which was regenerated in the presence of GSH. The copper–esculetin system was able to detect GSH in a cellular model.


2020 ◽  
Vol 21 (18) ◽  
pp. 6933
Author(s):  
Giuseppe Floresta ◽  
Nunzio Cardullo ◽  
Carmela Spatafora ◽  
Antonio Rescifina ◽  
Corrado Tringali

Rapid and efficient analyses of copper ions are crucial to providing key information for Cu2+ in living cells because of their biological importance. In this study, we reported one new turn-off fluorescent sensor for Cu2+ with a benzo[k,l]xanthene core, which served as an efficient cation sensor for copper ion over a wide range of other cations (Na+, K+, Ag+, Hg2+, Cd2+, Co2+, Ni2+, Zn2+, Mg2+, and Fe3+) owing to the catechol group in the aromatic core. The sensor showed selectivity for Cu2+ over other ions; the logKβ for Cu2+ binding to compound 1 had a value of 13.265. In the presence of Cu2+, sensor 1 provided significant fluorescence decrement; Co2+, and Ni2+ caused a fluorescence decrement when employed at a higher concentration than Cu2+, while Na+, K+, Hg2+, Cd2+, Zn2+, and Mg2+ metal ions produced only minor changes in fluorescence intensity. Fluorescence experiments demonstrate that compound 1 may have an application as a fluorescent probe for detecting Cu2+ with a limit of detection of 0.574 µM.



1999 ◽  
Vol 229 (1-2) ◽  
pp. 23-34 ◽  
Author(s):  
Naomi Zurgil ◽  
Menachem Kaufman ◽  
Inna Solodiev ◽  
Mordechai Deutsch


1974 ◽  
Vol 35 (C4) ◽  
pp. C4-157-C4-161
Author(s):  
L. BILLARD ◽  
M. NATTA


2005 ◽  
Vol 32 (06) ◽  
Author(s):  
G Fillon ◽  
M Neumann ◽  
R Zufferey ◽  
P Aebischer ◽  
HA Kretzschmar ◽  
...  




2016 ◽  
Vol 75 (11) ◽  
pp. 1001-1008
Author(s):  
S.V. Nikolayev ◽  
V. V. Pozhar ◽  
M. I. Dzyubenko ◽  
K. S. Nikolayev


2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Sachiko Yanagisawa ◽  
Minoru Kubo ◽  
Genji Kurisu ◽  
Shinobu Itoh

To unveil the activation of dioxygen on the copper centre (Cu<sub>2</sub>O<sub>2</sub>core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.<br>



Author(s):  
Mozhgan Ghorbani ◽  
Atefeh Araghi ◽  
Nabi Shariatifar ◽  
Seyed Hooman Mirbaha ◽  
Behrokh Marzban Abbasabadi ◽  
...  

Aims: The aim of this study was to investigate the toxic effect of Echium amoenum plants on the liver and kidney of animal model. Background: Echium amoenum is one of the medicinal plants containing pyrrolizidine alkaloids with several properties which has widely consumed among different communities. Objective: The toxic effects of Echium amoenum on the liver and kidney were investigated in this study. Methods: Sixty mice were kept for 28 days under the appropriate laboratory conditions. Echium amoenum extract (25, 12.5, 50 mg / kg, ip.) was administered for 28 days. At the end of experiment, blood samples were drawn and liver and kidneys were removed for evaluating hepatotoxicity and nephrotoxicity of extract. Additionally, experiments were conducted to assay the enzymatic and oxidative activities. Results: There was no significant difference in the levels of copper ion in the liver and kidneys among all groups. There was a significant difference in the levels of lipid peroxidation in the liver of treated groups versus control group. The significant difference was not observed in the levels of glutathione of the liver of all groups. However, the levels of glutathione of the kidney significantly decreased in the treated groups versus control group. There was no significant difference in the liver enzymes including ALP, SGOT, and SGPT between all groups. This indicates that damage increase with enhancing the time and concentrations of extract. Biochemical analysis showed the creatinine and urea levels did not change in the treated groups versus control group. Conclusion: According to the present findings, it is suggested that Echium amoenum causes hepatotoxicity and nephrotoxicity effects in dose and time dependent manner.



2018 ◽  
Vol 15 (1) ◽  
pp. 47-55
Author(s):  
Xuebing Li ◽  
Haifen Yang ◽  
Ning Wang ◽  
Tijian Sun ◽  
Wei Bian ◽  
...  

Background: Morin has many pharmacological functions including antioxidant, anticancer, anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection, gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore, it is necessary to determine the concentration of morin in biologic samples. Method: Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various concentrations of morin. Results: The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed fluorescent probe was applied to analysis of morin in human body fluids with recoveries of 98.0-102%. Conclusion: NSCDs were prepared by a microwave heating process. The present analytical method is sensitive to morin. The quenching process between NSCDs and morin is attributed to the static quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application prospect.



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