Acute lung injury (ALI) is a serious pulmonary inflammatory disease resulting from excessive reactive oxygen species (ROS) which could cause the damage of the alveolar epithelial cells and capillary endothelial cells. Peroxynitrite, as one of short-lived reactive oxygen species, is closely related to the process of ALI. Thus, it is important to monitor the fluctuation of peroxynitrite in living system for understanding the process of ALI.
View Article and Find Full Text PDFThermostability is considered a crucial parameter to evaluate the viability of enzymes in industrial applications. Over the past 31 years, many studies have been reported on the thermostability of enzymes. However, there is no systematic bibliometric analysis of publications on the thermostability of enzymes.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2022
Cysteine (Cys), one of the biological thiols, which plays critical roles in biological system regulating the balance of redox homeostasis. In order to monitor the level of Cys in the living cells and organisms, a chromogenic fluorescence probe Rhocl-Cys based on Rhodamine chloride exhibiting the preferable performance of fluorescence turn-on response reacting with Cys was presented. Rhocl-Cys responded rapidly to Cys within 20 min, and had stable fluorescence intensity within pH 6.
View Article and Find Full Text PDFAs a precursor of all reactive oxygen species (ROS), superoxide anions play an important role in organisms. However, excessive superoxide anions can cause various diseases. Thus, it is highly urgent to develop efficient tools for superoxide anion detection.
View Article and Find Full Text PDFMost of the ONOO fluorescent probes have restricted applications because of their aggregation-caused quenching (ACQ) effect, long response time and low fluorescence enhancement. Herein, we developed a novel AIEgen fluorescent probe (PE-XY) based on a benzothiazole and quinolin scaffold with high sensitivity and selectivity for imaging of ONOO. The results indicated that probe PE-XY exhibited fast response towards ONOO with 2000-fold enhancement of fluorescence intensity ratio .
View Article and Find Full Text PDFBone metastasis of malignant solid tumors has become one of the most serious complications, especially in breast cancer, which was particularly challenging for early detection and treatment in clinical practice. In this work, we reported a new fluorescently labeled bisphosphonate for bone metastasis detection of breast cancer. The designed probes were based on Rhodamine B and bisphosphonate as recognition group, which can specifically target hydroxyapatite (HA) existed in bone tissue.
View Article and Find Full Text PDFTheranostic prodrug was highly desirable for precise diagnosis and anti-cancer therapy to decrease side effects. However, it is difficult to conjugate chemo-drug and molecular probe for combined therapy due to the complex pharmacokinetics of different molecules. Here, a novel anticancer theranostic prodrug (BTMP-SS-PTX) had been designed and synthesized by conjugating paclitaxel (PTX) with 2-(benzo[d]thiazol-2-yl)-4-methoxyphenol (BTMP) through a disulphide (-S-S-) linkage, which was redox-sensitive to the high concentration of glutathione in tumors.
View Article and Find Full Text PDFEnzyme reaction has been accepted widely in numerous applications owing to the high efficiency and stereo-selectivity, as well as simple preparation by gene engineering. However, the fragility and complex purification process of the enzyme are long-standing problems which limit the large-scale application. One possible solution may be the enzyme immobilization.
View Article and Find Full Text PDFA rapid cell-permeating probe NJUXJ-1 was introduced for sensitive and selective detection of sulfite in living cells. It generated a turn-on response to sulfite with high sensitivity (detection limit 13.0 nM) and selectivity (at a physiological level) and low toxicity.
View Article and Find Full Text PDFA new selective probe with a quinoxalinone structure, QP-1, has been developed for detection of Cys from biothiols. QP-1 features superb selectivity to Cys and a wide pH range. QP-1 has selectivity to Cys over Hcy, GSH, other amino acids and ions.
View Article and Find Full Text PDFImmunoparalysis is an important pathological mechanism in sepsis. However, an effective small molecule therapy is lacking. Here, we show that ouabain, a Na(+),K(+)-ATPase ligand, can reverse immunoparalysis in vitro, in vivo, and in clinical samples.
View Article and Find Full Text PDFAn economical method for production of S-phenyl-L-cysteine from keratin acid hydrolysis wastewater (KHW) containing L-serine was developed by recombinant tryptophan synthase. This study provides us with an alternative KHW utilization strategy to synthesize S-phenyl-L-cysteine. Tryptophan synthase could efficiently convert L-serine contained in KHW to S-phenyl-L-cysteine at pH 9.
View Article and Find Full Text PDFUrea derivatives have been widely used in biology and medicine. The substituted urea derivative URD12 introduced in this study exhibits cytotoxic activity against the K562 human leukemia and KB human mouth epidermal carcinoma cell lines. To further study the bioactivity of URD12 and examine its feasibility as a new antitumor drug, we applied in vivo and in vitro assays to investigate the antitumor activity of URD12.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
January 2011
Fluorescence spectroscopy was used to investigate the influences of carbon nanotubes (CNTs) on the fluorescence of bovine serum albumin (BSA), the influences of CNTs on that of gatifloxacin (GFLX), and the influences of GFLX on that of BSA with or without coexisting CNTs under imitated physiological condition. The experimental results demonstrate that both gatifloxacin and carbon nanotubes could quench the intrinsic fluorescence of BSA, and the quenching mechanism is mainly static quenching. The fluorescence quenching action of GFLX on BSA was weakened in the presence of CNTs.
View Article and Find Full Text PDFA series of new 2-chloropyridine derivatives possessing 1,3,4-oxadiazole moiety were synthesized. Antiproliferative assay results indicated that compounds 6o and 6u exhibited the most potent activity against gastric cancer cell SGC-7901, which was more potent than the positive control. Especially, compound 6o exhibited significant telomerase inhibitory activity (IC(50)=2.
View Article and Find Full Text PDFIn this research, an improved method for preparation of optically pure β-hydroxy-α-amino acids, catalyzed by serine hydroxymethyl transferase with threonine aldolase activity, is reported. Using recombinant serine hydroxymethyl transferase (SHMT), an enzymatic resolution process was established. A series of new substrates, β-phenylserine, β-(nitrophenyl) serine and β-(methylsulfonylphenyl) serine were used in the resolution process catalyzed by immobilized Escherichia coli cells with SHMT activity.
View Article and Find Full Text PDFGlutamic acid gamma-methyl ester (GAME) was used as substrate for theanine synthesis catalyzed by Escherichia coli cells possessing gamma-glutamyltranspeptidase activity. The yield was about 1.2-fold higher than with glutamine as substrate.
View Article and Find Full Text PDFA series of N-alkyl substituted urea derivatives were synthesized and evaluated for their in vitro antibacterial and antifungal activities. The N-alkyl substituted urea derivatives bearing morpholine moiety (3a-3k) showed better activities than those bearing diethylamine moiety (2a-2f). Compounds having fluoro substituent at ortho (3c) and para (3b) positions of the phenyl ring exhibited potent antimicrobial activities against Gram-positive and Gram-negative bacteria as well as fungi.
View Article and Find Full Text PDFTheanine (γ-glutamylethylamide) is the main amino acid component in green tea. The demand for theanine in the food and pharmaceutical industries continues to increase because of its special flavour and multiple physiological effects. In this research, an improved method for enzymatic theanine synthesis is reported.
View Article and Find Full Text PDFA series of amide-coupled benzoic nitrogen mustard derivatives as potential EGFR and HER-2 kinase inhibitors were synthesized and reported for the first time. Some of them exhibited significant EGFR and HER-2 inhibitory activity. Of all the studied compounds, compounds 5b and 5t exhibited the most potent inhibitory activity, which was comparable to the positive control erlotinib.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
January 2008
The mechanism of color changes of sodium dodecyl sulphate(SDS) and Azur A (AA) before micelle formation was studied by spectral probe. The changes in the absorption spectra of SDS-AA and chondroitin sulfate(CS)-AA complexes were compared. The influence of ethanol and NaCl on the absorption spectra of SDS-AA complex was investigated.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
August 2006
On binding to deoxyribonucleic acid, the complex of terbium-ciprofloxacin (Tb(3+)-CIP) increases its fluorescence quantum efficiency. Based on this, an easy, rapid and sensitive method for the determination of DNA was developed. Like ethidium bromide (EB), the complex can be intercalated into DNA bases, but it is non-poisonous.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
March 2006
Using lomefloxacin-terbium as a fluorescent probe, the interaction of LFLX-Tb3+ and bovine serum albumin (BSA) was investigated by fluorescence spectra. The interaction of LFLX and BSA is quite strong. LFLX can affect the conformation of BSA to some degree.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
September 2005
The interaction of bovine serum albumin (BSA), sodium dodecyl sulphate (SDS) and Azur A(AA) was studied by spectral probe. The influence of the molar ratio of SDS/BSA on the absorption spectra of BSA-SDS-AA complex was investigated. It was found that the new absorption peak and color changes generated by BSA-SDS-AA complex arose from the difference in the spatial orientation aggregative degree of AA binding on BSA-SDS-AA complex.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
April 2005
In order to understand the mechanism of the interaction of sulfate polysaccharides and small molecules at molecular level, the structure of pachymaran was decorated by Wolfrom, and sulfation pachymaran (SP) was prepared. The maximum binding number (N = 54) and the binding equilibrium constant (K = 1.563 x 10(6)) of the sulfation pachymaran and methylene blue (MB) were obtained by the exoterica model.
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