Preparative Layer Chromatography Research Articles

Preparative chromatography in hollow cylinders made from stacked discs

A tube-shaped layer made with perforated cylindrical discs of adsorbent material has been used in this work, in order to simplify the application of samples in a narrow band as well as their separation after development during preparative layer chromatography. The preparation of discs of several adsorbents, several development techniques and their application to the purification of organic dyes have also been studied.

Isolation of oleandrin by preparative layer chromatography. Relationship between oleandrin content and cambium rhythm

The oleandrin content of leaves of Nerium oleander L. has been evaluated monthly, over a period of 15 months, by a spectrophotometric method after solvent extraction, chromatographic separation on silica gel preparative layers and column purification. The amount of oleandrin is connected with the cambium meristem rhythm of the stem during different months of the year. It has been shown that the increase of oleandrin content is connected with the cambium reactivation which, in turn, is affected by the weather conditions.

Nonacyclic amides from lichens of the genus [formula omitted

Preparative layer chromatography of the ethereal extracts of a chemical strain of the lichen Xanthopannelia scabrosa (Tayl.) Hale has led to our isolating four novel nitrogen containing esters' in addition to the known metabolites, usnic acid (1) and norlobaridone (2). The multicyclic diol moiety from which natural esters are derived has been termed scabrosin. Hence we describe the new metabolites as scabrosin 4,4'-diacetate (31, 0 m.p. 262 , scabrosin 4-acetate-4'-butyrate (4), m.p. 216-S-217.5', [a];,', -960G, scabrosin 4,4'-dibutyrate (2): m.p. 196-7' and scabrosin 4-acetate-4'-hexanoate (6), m.p. 213'. en3 OH 0 CH oa3

Untersuchungen in der Isochroman‐ und Isothiochroman‐Reihe, XX. Über Derivate des 1,1′‐Methylenbis(isothiochromans)

Investigations in the Isochromane and Isothiochromane Series, XX. Derivatives of 1,1′‐Methylenebis(isothiochromane)Isothiochromane‐1‐carbonitrile (1) and isothiochromane‐2,2‐dioxide (2) react via the carbanions 3 and 4 with diiodomethane to give mixtures of the racemic and the meso form of 1,1‐methylenebis‐(isothiochromanes) 5A/5B and 8A/8B, respectively. The separation of the diastereomers is achieved by fractionating crystallization combined with preparative layer‐chromatography.

Antibiotica aus algen—XVI : Polyhydroxyphenyläther aus der phaeophycee Halidrys siliquosa

With the aid of preparative layer chromatography several compounds could be isolated from a mixture of acetylated phenols obtained from Halidrys siliquosa (L.) Lyngbye. Peracetylated heptafuhalol as well as its deacetylpermethyl derivative were examined by MS, IR, 1H NMR and 13C NMR methods. Other constituents are probably lower members of a homologous series with 6, 5 and 4 phloroglucinol nuclei, respectively. The established building principle is also valid for a “high molecular mass polymer” fraction of acetylated phenols from Halidrys. The free phenols have the properties of tannins, and will be denoted phlorotannins.

Potential antitumor agents: A cytotoxic cardenolide from coronilla varia L

AbstractAn alcoholic extract of the seeds of Coronilla varia L. showed inhibitory activity against KB cells in culture and was fractionated through a series of partitions, column chromatography, and preparative layer chromatography to yield hyrcanoside, daphnoretin, scopoletin, and umbelliferone. Hyrcanoside was also tested in the PS mouse leukemia assay and showed borderline activity.

Preparative-layer chromatography of multisulphur compounds

This report describes the preparative scale separation of 1,2,3-trithians by thin-layer chromatography.

The differentiation of anomeric configuration and ring size in aryl ribosides by thin-layer and preparative layer chromatography

The differentiation of anomeric configuration and ring size in aryl ribosides by thin-layer and preparative layer chromatography

Isolation of aflatoxin-related substance from tobacco.

None of the known aflatoxins were isolated from 21 tobacco products and 14 alcoholic beverages analyzed by chloroform and acetone extraction, preparative and thin layer chromatography, ultraviolet and fluorescence emission analysis, and melting point determinations. One sample of tobacco and tobacco tar did contain small quantities of a coumarin chemically closely related to aflatoxin B2. This substance (T2) is lethal for chicken embryos, with a potency of approximately 1/89 that of aflatoxin B1 and two thirds that of aflatoxin B2; T2 apparently survives the smoking process, raising the possibility that it may contribute to cigarette-related carcinogenesis. The possibility that aflatoxin contamination of crops utilized in the preparation of alcoholic beverages might contribute to alcohol-related hepatic cirrhosis and hepatoma was not substantiated in this study.

Isolierung, Struktur und Synthese des Metaboliten von Azapropazon‐dihydrat

AbstractThe renal excretion of AZAPROPAZONE‐DIHYDRATE (X) Handelsname: PROLIXAN®. Hersteller: Siegfried AG, Zofingen. by humans was investigated. Following oral administration a new substance was detected in the urine besides X by TLC. Both compounds were separated by preparative layer chromatography and shown to be unchanged X and its hydroxylated metabolite VIII. The structure of VIII was established by chemical and spectroscopic methods (IR., NMR.) and confirmed by synthesis (Scheme 1).

Hilfsmittel für die präparative schichtchromatographie

Device for preparative layer chromatography An apparatus for preparative layer chromatography is described. It allows the simultaneous development of up to forty plates of 1 m length.

The determination of sulphur in lubricating oil fractions and in fuel oils—a coulometric method

The original combustion-microcoulometric method in which the Dohrmann microcoulometer is used for the determination of trace amounts of sulphur in organic liquids has been modified. The inlet to the microcoulometer has been re-designed to permit complete combustion of oils to take place in the inlet. The modified inlet and flow systems have been used for the determination of sulphur in oil fractions obtained from preparative layer chromatography and in fuel oils.

Examination of short chain polymers of α-methylstyrene by thin-layer chromatography

The protonated reaction products from experiments designed to prepare dimer and tetramer of α-methylstyrene anionically have been examined by thin-layer chromatography, and have been shown to be more complex than previously predicted. The three major constituents of both systems have been separated by preparativelayer chromatography in sufficient quantities to enable structural examination by nuclear magnetic resonance spectroscopy and mass spectroscopy. The tetramer dianion has been shown to be in equilibrium with dimer, trimer and small quantities of higher oligomeric dianions.

Fractionation of poly(methylene-2-hydroxybenzoic acid) by preparative layer chromatography

Fractionation of poly(methylene-2-hydroxybenzoic acid) by preparative layer chromatography

The composition of beeswax alkyl esters

AbstractThe alkyl esters of beeswax, after isolation from the unhydrolyzed wax by preparative layer chromatography (PLC), have been analyzed directly by high temperature GLC using 1.5% OV1 as liquid phase. In two commercial wax samples examined the ester homologues are predominantly even carbon numbered ranging from C36 to C54. The principal alkyl esters are C40, C42, C44, C46 and C48. The GLC analysis of the ester hydrolysis products revealed that the variations in ester chain length are produced by variations in the esterified primary alcohol chain lengths. The esterified fatty acid is chiefly hexadecanoic acid. The esterified fatty acids differ in composition from the free fatty acids which are also present in the wax.

A technique for sample application in preparative-layer chromatography

A technique for sample application in preparative-layer chromatography

3-Hydroxy-2-methyl-and 3-hydroxy-2,4-dimethyl-substituted long-chain carboxylic esters

3-Hydroxy-2-methyl- and 3-hydroxy-2,4-dimethyl-substituted long-chain carboxylic esters have been prepared by routes involving (i) reduction of the corresponding keto-esters, and (ii) Reformatsky reaction between the appropriate aldehydes and ethyl α-bromopropionate. The resulting 2,3-erythro- and threo-isomers of ethyl 3-hydroxy-2-methyleicosanoate, and of methyl and ethyl 3-hydroxy-2,4-dimethyldocosanoate have been separated by chromatography. High resolution i.r. studies of these esters are described, and n.m.r. data for the ethyl esters are also reported and discussed. The diastereoisomers of 1,3-dihydroxy-2-methyldocosane, obtained as by-products, were separated by preparative layer chromatography, and converted into the corresponding ethylidene acetals. High-resolution i.r. studies of the diols, and n.m.r. data for the diols and their acetals are reported.The conversion of ethyl 3-hydroxy-2,4-dimethyldocosanoate into trans- and cis-αβ-unsaturated esters was also studied. The resulting methyl trans- and cis-2,4-dimethyldocos-2-enoates were separated and identified by their u.v. and n.m.r. spectra.

Intramolecular bonding and relative stabilities of syn- and anti-α-hydroximino-ketones

Spectroscopic studies show that, in solution, neither benzil α-monoxime (anti-isomer) nor the more stable β-monoxime (syn-isomer) exhibits intramolecular bonding. The syn- and anti-forms of 3-hydroximinocamphor are effectively separated by preparative layer chromatography: here the syn-isomer, which is internally bonded, is much less stable than the anti-compound.

Improved method for preparative layer chromatography

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTImproved method for preparative layer chromatographyMartin H. Stutz, William D. Ludemann, and Samuel. SassCite this: Anal. Chem. 1968, 40, 1, 258–259Publication Date (Print):January 1, 1968Publication History Published online1 May 2002Published inissue 1 January 1968https://doi.org/10.1021/ac60257a013RIGHTS & PERMISSIONSArticle Views138Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (267 KB) Get e-Alerts Get e-Alerts

Chromatography of organic compounds : II. Inverted dry-column chromatography

A column chromatographic method is described, which directly adopts the results of thin-layer chromatography. The method appears to have several advantages over preparative layer chromatography and conventional column chromatography.