Esters, detection paper chromatography

Cinnamyl anthranilate can be assayed by a method based on ester hydrolysis. Bulk samples of food-grade cinnamyl anthranilate have been analysed for purity by thin-layer chromatography and high-performance liquid chromatography. A method has been described for determining the content of this compound in food products by steam distillation followed by paper chromatography and examination under ultraviolet light it has a limit of detection of 1 pg (lARC, 1983). 

M. Abdel-Akher and F. Smith, The detection of carbohydrate esters and lactones after separation by paper chromatography, J. Am. Chem. Soc., 73 (1951) 5859-5861. 

Donner, R. and Lohs, K., Cobalt chloride in the detection of organic phosphate ester by paper and especially thin-layer chromatography, J. Chromatogr., 17, 349, 1965 Chem. Abs., 62, 13842d, 1965. 

The Lobry de Bruyn reaction can be carried out on the paper, followed by chromatography of the products.167 168 The procedure of Bayly and Bourne22 for forming benzylamine derivatives of oligosaccharides on filter paper has been mentioned previously. Enzymic hydrolysis of phosphate esters, in conjunction with paper chromatography, aids detection of the spots.126... 

The isolation and identification of the light, acid, and base sensitive musca-aurins posed considerable separation problems which were overcome by careful, repeated chromatography on Sephadex 188, 192). Hydrolysis of the individual musca-aurins gave betalamic acid (174) together with the constituent amino acids which were detected by electrophoresis and paper chromatography and identified by linked gas chromatography-mass spectrometry of their 7V-trifluoroacetyl methyl esters 189,192). 

Other reagents suitable for paper chromatography are also applicable to TLC (Nos. 10,21,134,159,178,234, 255) and some other reagents containing periodic acid. Of these, iodine vapor [18] has the most universal application since it detects a variety of carbohydrate derivatives including the free sugars, partially and fully substituted methyl and benzyl ethers, esters and acetals. Although iodine is less sensitive than suKuric acid, it is non-destructive in the short exposure time required (5—20 min) and can therefore be used to detect components on preparative plates or for quantitative analysis. The adsorbed iodine disappears when the plate is exposed to the air. 

The reason for this error is shown in Figure 3. When the coenz3mie A ligase preparation (which is a non-purified enzyme extract) is incubated with coenzyme A, ATP, Mg + and -succinylbenzoic acid at pH 7.9, a mixture of the aliphatic (VI), aromatic (VII) and di-coenz5nne A ester is formed. This mixture can be separated by HPLC. In contrast, if the same experiment is carried out at the lower pH of 6.5, only the "aliphatic ester (VI) is formed and no aromatic (VII) or di-coenzyme A ester is detectable under these conditions. After incubation at pH 7.9 the mixture of mono-coenzyme A esters was purified by paper chromatography. While the aromatic coenzyme A ester (VII) is rather stable, the aliphatic ester (VI) has a half life of 15 minutes at neutral pH and room temperature. The product of decomposition is the spiro-dilactone of -succinylbenzoic acid (XII) (Fig. 3). After methylation with diazomethane a mixture of the methylated coenzyme A esters (VIII, IX) is formed including an unknown... 

Br-Butanone-Pi. An aqueous solution (10 ml) containing 179 mg (0.025 M) of the triscyclohexylammonium salt of the diethyl ketal is swirled with 2 g of Dowex 50 (H ) to remove cyclohexylammonium ions and then filtered. The resulting acidic solution is incubated at 40 for 3 hr. At this time paper chromatography (same system as above) followed by visualization with the spray for phosphate esters" revealed an essentially complete conversion of the ketal Rf = 0.53) to the ketone (Rf = 0.23). The latter component gave an immediate positive response with a silver nitrate dip," whereas the ketal was not detected. Solutions of... 

Hexahydroxydiphenic acid in a bound form (3) is readily detected in a plant extract by an old but very distinctive color test - the Procter-Paessler reaction. Esters of type 3 react with nitrous acid to give a carmine or rose red, changing to brown-green, then purple, and finally indigo blue. The chemical basis of this reaction has not been discussed but it has been employed by Bate-Smith (6, 7) for the quantitative determination of 3 in plant extracts, and it forms the basis of a very useful spray reagent for the detection of 3 by paper chromatography (6, 7, 43). 

The most suitable method for the detection and identification of alcohols is the utilization of the reaction with 3,5-dinitrobenzoyl chloride the reaction has been very thoroughly studied and it can be used in combination with paper chromatography for simultaneous detection and identification. As they serve for identification purposes, the esters of 3,5-dinitrobenzoic acid were prepared from a maximum number of alcohols. Another advantage consists in the possibility of preparing these derivatives even when the alcohols are available only in the form of their aqueous solutions. 

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