126605-73-0Relevant articles and documents
NbCl5-Promoted Synthesis of Fluorescein Dye Derivatives: Spectroscopic and Spectrometric Characterization and Their Application in Dye-Sensitized Solar Cells
da Silva, Bruno Henrique Sacoman Torquato,Bregadiolli, Bruna Andressa,Graeff, Carlos Frederico de Oliveira,da Silva-Filho, Luiz Carlos
, p. 261 - 269 (2017)
Fluorescein has several applications owing to its properties, such as high molar absorptivity, high fluorescence quantum yield, high photostability, and wavelengths of absorption and emission in the visible region. The syntheses of fluorescein derivatives between phenol and anhydride derivatives by using NbCl5 as a Lewis acid is described. The products have high yields and short reaction times are observed. The study of the UV/Vis and fluorescence spectra of these derivatives and their application in dye-sensitized solar cells is also described.
Extraordinary Character of the Solvent Influence on Protolytic Equilibria: Inversion of the Fluorescein Ionization Constants in H2O-DMSO Mixtures
Mchedlov-Petrossyan, Nikolay O.,Mayorga, Rafael Salinas
, p. 3025 - 3032 (1992)
The protolytic equilibria of fluorescein and sulfonefluorescein in the H2O-DMSO system are studied spectrophotometrically.The pKa values, as well as the absorption spectra, attributed to individual ionic (molecular) forms of the dyes, are determined.The paH* scales used in pKa calculations were estimated by the indicator method (sulfonephthalein series) through the overlapping procedure.The character of the solvent influence on the fluorescein stepwise ionization (H3R(+) H2R HR(-) R(2-); Ka0, Ka1 and Ka2, respectively) results in extraordinary interrelations between the Ka constants, up to inversion: pKa1 > pKa2.The Ka1/Ka2 ratio changes gradually from 224 in H2O to 0.045 in 91percent DMSO; meanwhile the Ka0/Ka1 ratio increases from 204 to 7*1010.The anomalous character of the fluorescein pKa dependence on the content of DMSO (up to pKa1 > pKa2) is explained through the tautomeric equilibria shift and the nature of the functional groups.The tautomerization constants of the fluorescein neutral form are given as obtained on the basis of the extrathermodynamic assumption proposed previously (N.O.Mchedlov-Petrossyan, Zh.Anal.Khim. 1979, 34, 1055).This allowed calculation of the ionization microconstants (k), which were found to be in agreement with pKa values of model compounds.
Molecular-level understanding of the photocatalytic activity difference between anatase and rutile nanoparticles
Kim, Wooyul,Tachikawa, Takashi,Moon, Gun-Hee,Majima, Tetsuro,Choi, Wonyong
, p. 14036 - 14041 (2014)
The generation of oxidants on illuminated photocatalysts and their participation in subsequent reactions are the main basis of the widely investigated photocatalytic processes for environmental remediation and selective oxidation. Here, the generation and the subsequent diffusion of ·OH from the illuminated TiO2 surface to the solution bulk were directly observed using a single-molecule detection method and this molecular phenomenon could explain the different macroscopic behavior of anatase and rutile in photocatalysis. The mobile ·OH is generated on anatase but not on rutile. Therefore, the photocatalytic oxidation on rutile is limited to adsorbed substrates whereas that on anatase is more facile and versatile owing to the presence of mobile ·OH. The ability of anatase to generate mobile COH is proposed as a previously unrecognized key factor that explains the common observations that anatase has higher activity than rutile for many photooxidative reactions.
Rapid and selective detection of Cys in living neuronal cells utilizing a novel fluorescein with chloropropionate-ester functionalities
Murale, Dhiraj P.,Kim, Hwajin,Choi, Wan Sung,Churchill, David G.
, p. 5289 - 5292 (2014)
A chloropropionate-caged fluorescein probe allows for prompt detection of cysteine over other biothiols, e.g., homocysteine with a limit of detection of 12.8 μM.
The Development of Fluorescent Probes for Visualizing Intracellular Hydrogen Polysulfides
Chen, Wei,Rosser, Ethan W.,Matsunaga, Tetsuro,Pacheco, Armando,Akaike, Takaaki,Xian, Ming
, p. 13961 - 13965 (2015)
Endogenous hydrogen polysulfides (H2Sn; n>1) have been recognized as important regulators in sulfur-related redox biology. H2Sn can activate tumor suppressors, ion channels, and transcription factors with higher potency than H2S. Although H2Sn are drawing increasing attention, their exact mechanisms of action are still poorly understood. A major hurdle in this field is the lack of reliable and convenient methods for H2Sn detection. Herein we report a H2Sn-mediated benzodithiolone formation under mild conditions. This method takes advantage of the unique dual reactivity of H2Sn as both a nucleophile and an electrophile. Based on this reaction, three fluorescent probes (PSP-1, PSP-2, and PSP-3) were synthesized and evaluated. Among the probes prepared, PSP-3 showed a desirable off/on fluorescence response to H2Sn and high specificity. The probe was successfully applied in visualizing intracellular H2Sn.
Extremely selective fluorescence detection of cysteine or superoxide with aliphatic ester hydrolysis
Murale, Dhiraj P.,Kim, Hwajin,Choi, Wan Sung,Kim, Youngsam,Churchill, David G.
, p. 46513 - 46516 (2014)
A novel fluorescence probe modality demonstrated with fluorescein affords a highly selective aqueous-based detection of cysteine over other biothiols, e.g. homocysteine, with a limit of detection of 11.3 μM.
Combinatorial Strategy to Identify Fluorescent Probes for Biothiol and Thiophenol Based on Diversified Pyrimidine Moieties and Their Biological Applications
Xie, Xilei,Li, Mengmeng,Tang, Fuyan,Li, Yong,Zhang, Leilei,Jiao, Xiaoyun,Wang, Xu,Tang, Bo
, p. 3015 - 3020 (2017)
We present a feasible paradigm of developing original fluorescent probes for target biomolecules via combinatorial chemistry. In this developmental program, pyrimidine moieties were investigated and optimized as unique recognition units for thiols for the first time through a parallel synthesis in combination with a rapid screening process. This time-efficient and cost-saving process effectively facilitated the developmental progress and provided detailed structure-reactivity relationships. As a result, Res-Biot and Flu-Pht were identified as optimal fluorescent probes for biothiol and thiophenol, respectively. Their favorable characteristics and superior applicability have been well demonstrated in both chemical and biological contexts. In particular, Res-Biot enables the direct visualization of biothiol fluctuations during oxidative stress and cell apoptosis, indicating its suitability in elucidation of a specific pathophysiological process in both living cells and living animals. Meanwhile, Flu-Pht is competent to visualize thiophenols without the interference from endogenous biothiols in living cells.
Inhibitory effects of cytochrome P450 enzymes CYP2C8, CYP2C9, CYP2C19 and CYP3A4 by Labisia pumila extracts
Pan, Yan,Tiong, Kai Hung,Mak, Joon Wah,Abd-Rashid, Badrul Amini,Ismail, Zakiah,Ismail, Rusli,Ong, Chin Eng
, p. 586 - 591,6 (2012)
Ethnopharmacological relevance: Labisa pumila (LP), popularly known with its local name, Kacip Fatimah, is a well known herb grown in Indochina and Southeast Asia and is traditionally used to regain energy after giving birth in women. The propensity of LP to cause drug-herb interaction via cytochrome P450 (CYP) enzyme system has not been investigated. Aim of the study: To evaluate the in vitro inhibitory effects of various LP extracts (aqueous, ethanol, dichloromethane (DCM) and hexane) on cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP2C19 and CYP3A4 activities. Materials and methods: Probe substrate-based high performance liquid chromatography (HPLC) methods were established for CYP2C9, CYP2C19 and CYP3A4 whereas a fluorescence-based enzyme assay was established for CYP2C8. The metabolite formations were examined after incubation of probe substrate with respective CYP isoform in the present or absent of LP extracts. The inhibitory effect of LP was characterized with kinetic parameters IC 50 and Ki values. Results: LP extracts showed differential effect of CYP activities with the order of inhibitory potency as follows: dichloromethane>hexane>ethanol>aqueous. This differential effect was only observed in CYP2C isoforms but not CYP3A4. Both the hexane and DCM extracts exhibited moderate to potent inhibition towards CYP2C activities in different modes including non-competitive, competive and mixed-type. The DCM effect was notably strong for CYP2C8 and CYP2C9 showing Ki values of below 1 μg/ml. The selectivity of LP for CYP2C isoforms rather than CYP3A4 may be attributed to the presence of relatively small, lipophilic yet slightly polar compounds within the LP extracts. Conclusions: The results of our study revealed that phytoconstituents contained in LP, particularly in hexane and dichloromethane extracts, were able to selectively inhibit CYP2C isoforms. The inactivation was characterized by low Ki values, in particular, in CYP2C8 and CYP2C9. These in vitro data indicate that LB preparations contain constituents that can potently inhibit CYP2C activities and suggest that this herb should be examined for potential pharmacokinetic drug interactions in vivo.
Effect of solvent-water mixtures on the prototropic equilibria of fluorescein and on the spectral properties of the monoanion
Klonis, Nectarios,Sawyer, William H.
, p. 179 - 185 (2000)
A spectral resolution procedure was used to resolve the absorption, excitation and emission spectra of the fluorescein monoanion in a number of solvent-water mixtures. This permitted an analysis of the effect of the solvent environment on the spectral properties of the monoanion and on the lactone/monoanion/dianion transitions of fluorescein. The monoanion excitation and emission spectra show relatively small changes with changing environment, a behavior that is related to the hydrogen-bonding environment of the solvent-water mixtures. There is also a general increase in the quantum yield of the monoanion from 0.36 in water to values up to 0.49 in the solvent-water mixtures. The presence of solvent also results in a general increase in the lactone content and in the monoanion:dianion and lactone:monoanion ratios. General polarity effects alone cannot account for the observed effects on the prototropic transitions indicating that specific solute-solvent effects involving hydrogen bonding perturb the prototropic equilibria of fluorescein.
Ferric hydrogensulphate as a recyclable catalyst for the synthesis of fluorescein derivatives
Eshghi, Hossein,Mirzaie, Narges
, p. 504 - 509 (2011)
Polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of ferric hydrogensulphate under melt conditions. The reactions proceeded in short reaction times by using a catalytic amount of Fe(HSO4)3 and the corresponding fluorescein derivatives were obtained in high yields. The simplicity, scale-up, along with the use of an inexpensive, non-toxic, recyclable catalyst of an environmentally benign nature, are other remarkable features of the procedure. The absorption and emission properties of these fluorescein derivatives were studied.
