Search results for "Thin-layer chromatography"
showing 10 items of 42 documents
Gel Chromatography on Cellulose
1971
HPTLC Phenolic Profiles as Useful Tools for the Authentication of Honey
2018
The present study reveals the utility of high-performance thin-layer chromatographic (HPTLC) fingerprinting of phenolic constituents for the authentication of monofloral honeys. The obtained data enables a more complete assessment of honey quality and the identification of emerging threats to honey quality. The developed procedure facilitates differentiation of varietal honeys and detection of honey adulterations. We used an HPTLC fingerprint analysis to determine the characteristic patterns of different honey types (willow, buckwheat, heather, pine honeydew, and manuka honey). The HPTLC chromatograms were used to determine the differences in the botanical origin of the honey samples on the…
Über die Verwendung von homogenen azeotropen Gemischen in der Dünschichtchromatographie, 1. Mitt.
1968
Homogene azeotrope Gemische wurden auf ihre Brauchbarkeit fur die Dunnschichtchromatographie untersucht. Mehrere Gemische zeigten sich zur Trennung verschiedener Substanzklassen, z. B. Alkaloiden oder Sulfonamiden geeignet. Die DC mit diesen Gemischen fuhrt zu besonders konstanten Rf-Werten und zeichnet sich durch Wirtschaftlichkeit aus. The usefulness of homogeneous azeotropic mixtures in thin layer chromatography has been studied. Several mixtures are qualified for the separation of different classes of substances, for example alkaloids and sulfonamides. TLC with azeotropic solvents leads to especially constant Rf-values and is remarkably economical.
Evidence for pleural epithelial-mesenchymal transition in murine compensatory lung growth
2017
In many mammals, including rodents and humans, removal of one lung results in the compensatory growth of the remaining lung; however, the mechanism of compensatory lung growth is unknown. Here, we investigated the changes in morphology and phenotype of pleural cells after pneumonectomy. Between days 1 and 3 after pneumonectomy, cells expressing α-smooth muscle actin (SMA), a cytoplasmic marker of myofibroblasts, were significantly increased in the pleura compared to surgical controls (p < .01). Scanning electron microscopy of the pleural surface 3 days post-pneumonectomy demonstrated regions of the pleura with morphologic features consistent with epithelial-mesenchymal transition (EMT); nam…
A discoidal lipoprotein from the coelomic fluid of the polychaete Nereis virens.
2005
A discoidal lipoprotein was isolated from the coelomic fluid of the polychaete, Nereis virens, by density gradient centrifugation. The lipoprotein was present in both sexes and moved as a uniform band in an agarose gel. The average diameter of the lipoprotein particles determined by electron microscopy was 42 nm with a thickness of 10 nm. SDS electrophoresis showed two apoprotein subunits with molecular masses of 247 and 85 kDa, respectively. In lectin blots, both apoproteins were reactive with Concanavalin A indicating the presence of N-glycans. The small subunit was also reactive with peanut lectin, indicating additional O-glycosylation. The total lipid content was 48% and consisted mainl…
Die darstellung nitrierter phenolischer mehrkernverbindungen durch kondensation von nitrophenol und seinen derivaten
1970
Es wurden einige Mehrkernverbindungen dargestellt, die aus Nitrophenoleinheiten bestehen, welche in ortho-Stellung zur phenolischen OH-Gruppe uber Methylengruppen verbunden sind. Die Nitrierung fertiger phenolischer Mehrkernverbindungen ist hierzu nicht geeignet. Jedoch gelingt die Darstellung durch Kondensation von Nitrophenolen mit Formaldehyd oder durch Kondensation von chlormethylierten Nitrophenolen mit anderen Nitrophenolen. Im ersten Fall ist die Bildung des Benzdioxanringes als Nebenreaktion zu beobachten. All dargestellten Mehrkernverbindungen wurden dunnschichtchromatographisch auf Reinheit gepruft; ihre Struktur wurde in beinahe allen Fallen durch voneinander unabhangige. Synthes…
Die direkte quantitative Auswertung von Dünnschichtchromatogrammen durch Remissions- und Fluoreszenzmessungen 3. Mitt.: Bestimmung von Morphin, Codei…
1971
Es wird ein Verfahren zur quantitativen Bestimmung verschiedener Opiumalkaloide nebeneinander beschrieben, das auf der direkten Auswertung von DC durch Remissionsmessung mit Hilfe eines Chromatogramm-Spektralphotometers beruht. Anstelle des bisher ublichen Messpaltes wurde fur die Auswertung eine Kreisblende benutzt. Hierbei ist vorteilhaft, das die Form der Absorptions-Orts-Kurven keinen Einflus auf die Mesgenauigkeit besitzt, da nur die Peakhohe ausgewertet wird. Quantitative Determination of Opium Alkaloids A method for the quantitative determination of a number of single alkaloids in opium alkaloid mixtures is described, which is based on the direct evaluation of TLC by reflectance with…
Validation of liposomal lipid composition by thin-layer chromatography.
2012
Liposomes of different sizes are frequently used model systems for cellular membranes. To mimic the cellular environment, these liposomes are often prepared from a mixture of different lipids in organic solution. The preparation involves, at some point, the transfer into aqueous solution. Thus, both the total amount of lipid and the relative amount of each lipid species might deviate from the original composition in the organic solvent. We used thin-layer chromatography combined with a lipid extraction step to check whether the liposomes in the final aqueous solution have the intended composition. This allows determination of the lipid composition not only for large unilamellar vesicles, bu…
Development of a high performance thin layer chromatography method for the rapid qualification and quantification of phenolic compounds and abscisic …
2019
Honey is a natural product with a complex chemical composition consisting of sugars and other bioactive compounds. It is important in many traditional systems of medicine, exhibiting interesting bioactivities, in particular antimicrobial, anti-inflammatory and antioxidant effects. Authentication of botanical origin of honeys is particularly important in this context. Therefore, methods for quality control of honey and detection of its adulteration are very important. A HPTLC method for the quantitative determination of phenolic compounds in honey was developed for the first time. Seven phenolic compounds were detected and determined quantitatively in lime and acacia honey samples. The obtai…
68Ge content quality control of 68Ge/68Ga-generator eluates and 68Ga radiopharmaceuticals – A protocol for determining the 68Ge content using thin-la…
2014
(68)Ge breakthrough from a (68)Ge/(68)Ga-generator appears to be one of the most critical parameters for the routine clinical application of this generator and (68)Ga-radiopharmaceuticals. We report a TLC-based (thin-layer chromatography) protocol which allows the (68)Ge breakthrough of a generator to be determined within 1 h post-initial elution. The protocol can also be adapted to allow the (68)Ge content of a (68)Ga-radiopharmaceutical preparation to be determined prior to in vivo application.