Search results for "molecular probes"
showing 10 items of 24 documents
Molecular docking-based design and development of a highly selective probe substrate for UDP-glucuronosyltransferase 1A10
2018
Intestinal and hepatic glucuronidation by the UDP-glucuronosyltransferases (UGTs) greatly affect the bioavailability of phenolic compounds. UGT1A10 catalyzes glucuronidation reactions in the intestine, but not in the liver. Here, our aim was to develop selective, fluorescent substrates to easily elucidate UGT1A10 function. To this end, homology models were constructed and used to design new substrates, and subsequently, six novel C3-substituted (4-fluorophenyl, 4-hydroxyphenyl, 4-methoxyphenyl, 4-(dimethylamino)phenyl, 4-methylphenyl, or triazole) 7-hydroxycoumarin derivatives were synthesized from inexpensive starting materials. All tested compounds could be glucuronidated to nonfluorescen…
The influence of tin compounds on the dynamic properties of liposome membranes: A study using the ESR method
2005
AbstractThe influence of organic and inorganic compounds of tin on the dynamic properties of liposome membranes obtained in the process of dipalmitoylphosphatidylcholine (DPPC) sonication in distilled water was investigated. This was carried out by means of the spin ESR probe method. The probes were selected in such a way as to penetrate different areas of the membrane (a TEMPO probe, 5-DOXYL stearic acid, 16-DOXYL stearic acid). Four compounds of tin were chosen: three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic one, SnCl2. The investigated compounds were added to a liposome dispersion, which was prepared prior to that. The concentration of the admixture was change…
Solution versus Fluorous versus Solid-Phase Synthesis of 2,5-Disubstituted 1,3-Azoles. Preliminary Antibacterial Activity Studies
2009
A small library of compounds with an oxa(thia)zole scaffold and structural diversity in both positions 2 and 5 has been synthesized. Double acylation of a protected glycine affords intermediate α-amido-β-ketoesters, which in turn can be dehydrated to afford 1,3-oxazoles or reacted with Lawesson’s reagent to furnish 1,3-thiazoles. This procedure was designed with its adaptation to fluorous techniques in mind. Thus, when a protected glycine with a fluorous tag in the ester moiety is used as a starting material, the synthesis can be easily completed without column chromatography purification of intermediate compounds with good to excellent yields, thus affording a suitable entry to the prepara…
Recent advances in smart biotechnology: Hydrogels and nanocarriers for tailored bioactive molecules depot
2017
Over the past ten years, the global biopharmaceutical market has remarkably grown, with ten over the top twenty worldwide high performance medical treatment sales being biologics. Thus, biotech R&D (research and development) sector is becoming a key leading branch, with expanding revenues. Biotechnology offers considerable advantages compared to traditional therapeutic approaches, such as reducing side effects, specific treatments, higher patient compliance and therefore more effective treatments leading to lower healthcare costs. Within this sector, smart nanotechnology and colloidal self-assembling systems represent pivotal tools able to modulate the delivery of therapeutics. A comprehens…
Nanoprobing the acidification process during intracellular uptake and trafficking
2015
Abstract Many nanoparticular drug delivery approaches rely on a detailed knowledge of the acidification process during intracellular trafficking of endocytosed nanoparticles (NPs). Therefore we produced a nanoparticular pH sensor composed of the fluorescent pH-sensitive dual wavelength dye carboxy seminaphthorhodafluor-1 (carboxy SNARF-1) coupled to the surface of amino-functionalized polystyrene NPs (SNARF-1-NP). By applying a calibration fit function to confocal laser scanning microscopy (CLSM) images, local pH values were determined. The acidification and ripening process of endo/lysosomal compartments containing nanoparticles was followed over time and was found to progress up to 6h to …
Selective chromo-fluorogenic detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) with a unique probe based on a boron dipyrromethene …
2014
[EN] A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with…
Solvation of a probe molecule by fluid supercooled water in a hydrogel at 200 K
2008
By combining electron paramagnetic resonance (EPR) measurements on a nitroxide probe and differential scanning calorimetry (DSC), we demonstrate existence of liquid supercooled water in a silica hydrogel with high hydration level down to temperatures of at least 198 K. Besides the major fraction of liquid supercooled water, a minor fraction crystallizes at about 236 K during cooling and melts at 246 K during heating. The liquid domains are of sufficient size to solvate the nearly spherical paramagnetic probe molecule TEMPO with a diameter of about 6 angstrom. Analysis of EPR spectra provides the rotational correlation time of the probe that is further used to compare the viscosity of the su…
Cholesterol reporter molecules.
2007
Cholesterol is a major constituent of the membranes in most eukaryotic cells where it fulfills multiple functions. Cholesterol regulates the physical state of the phospholipid bilayer, affects the activity of several membrane proteins, and is the precursor for steroid hormones and bile acids. Cholesterol plays a crucial role in the formation of membrane microdomains such as “lipid rafts” and caveolae. However, our current understanding on the membrane organization, intracellular distribution and trafficking of cholesterol is rather poor. This is mainly due to inherent difficulties to label and track this small lipid. In this review, we describe different approaches to detect cholesterol in …
Probes for studying cholesterol binding and cell biology.
2011
Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…
Hydrophobic pocket targeting probes for enteroviruses
2015
Visualization and tracking of viruses without compromising their functionality is crucial in order to understand virus targeting to cells and tissues, and to understand the subsequent subcellular steps leading to virus uncoating and replication. Enteroviruses are important human pathogens causing a vast number of acute infections, and are also suggested to contribute to the development of chronic diseases like type I diabetes. Here, we demonstrate a novel method to target site-specifically the hydrophobic pocket of enteroviruses. A probe, a derivative of Pleconaril, was developed and conjugated to various labels that enabled the visualization of enteroviruses under light and electron micros…