Synthesis of L-glucurone. Conversion of D-glucose into L-glucose

1969 ◽  
Vol 47 (21) ◽  
pp. 3931-3934 ◽  
Author(s):  
Walter Sowa
Keyword(s):  
Thin Layer ◽  
Trifluoroacetic Acid ◽  
Periodic Acid ◽  
Small Scale ◽  
Borohydride Reduction ◽  
Isopropylidene Derivative ◽  
Molar Equivalent ◽  
Intermediate Oxidation ◽  
Layer Chromatography ◽  
Hydrolysis Of

L-Glucurone (2) was readily prepared on a small scale by treatment of D-glycero-D-gulo-heptono-lactone (1) with a molar equivalent of periodic acid; thin–layer chromatography was used for its isolation. On a larger scale pure crystalline L-glucurone was obtained in over 80% yield from 3,5;6,7-di-O-isopropylidene-D-glycero-D-gulo-heptonolactone (4) in two steps consisting of concomitant hydrolysis and oxidation of 4 with periodic acid followed by treatment of the intermediate oxidation product with trifluoroacetic acid. L-Glucose was prepared from L-glucurone by borohydride reduction and hydrolysis of the 1,2-O-isopropylidene derivative. Since 1 was derived from D-glucose, the result of this series of reactions was the conversion of D-glucose into its enantiomer L-glucose.

Confirmatory Tests for Aflatoxin B1

1964 ◽  
Vol 47 (5) ◽  
pp. 801-803 ◽  
Author(s):  
Peter John Andrellos ◽  
George R Reid
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Formic Acid ◽  
Thionyl Chloride ◽  
Aflatoxin B1 ◽  
Trifluoroacetic Acid ◽  
Reaction Products ◽  
Confirmatory Tests ◽  
Aflatoxin B ◽  
Layer Chromatography

Abstract Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.

scholarly journals ISOLATION AND ANALYSIS OF STEROIDAL SAPONINS FROM POLYGONATUM ODORATUM (MILL.) DRUCE

2021 ◽  
Vol 55 ◽  
pp. 135-140
Author(s):  
Cristina MOGOSAN ◽  
Ilioara ONIGA ◽  
Mircea TAMAS
Keyword(s):  
Thin Layer ◽  
Acid Hydrolysis ◽  
Thin Layer Chromatography ◽  
Biological Properties ◽  
Steroidal Saponins ◽  
Physico Chemical ◽  
Layer Chromatography ◽  
Hydrolysis Of

We isolated the steroidal saponins from the rhizomes of Polygonatum odoratum (Mill.) Druce with an efficiency of 4.50% which represents 7 fractions identified by thin-layer chromatography (TLC), of which 3 were furostanics and 4 spirostanics. After the acid hydrolysis of the saponins, one aglycone (sapogenine) was identified by TLC. Further, we have determined the physico-chemical and the biological properties of the isolated saponins.

Analysis of Chloroxuron Technical and Its Formulations: Collaborative Study

1978 ◽  
Vol 61 (6) ◽  
pp. 1499-1503
Author(s):  
Werner Heizler ◽  
Juerg Meier ◽  
Klaus Nowak ◽  
Rolf Suter ◽  
Hans P Bosshardt
Keyword(s):  
Thin Layer ◽  
Alkaline Hydrolysis ◽  
Collaborative Study ◽  
Acid Extraction ◽  
Wettable Powder ◽  
Good Repeatability ◽  
Aoac Method ◽  
Layer Chromatography ◽  
Hydrolysis Of ◽  
Good Agreement

Abstract Chloroxuron technical and its 50% wettable powder were analyzed by 17 participants in a CIPAC collaborative study. The analytical method used involves acid extraction to remove interfering free amines, followed by alkaline hydrolysis of the extraction residue, distillation, and titration of the liberated dimethylamine. Related byproducts which may interfere are determined by semiquantitative thin layer chromatography. Results obtained from 17 government and industrial collaborators showed good repeatability within laboratories. Good agreement was also achieved between laboratories. A reproducibility of about 1.5% was obtained. The method has been adopted as an interim official CIPAC-AOAC method.

A PRACTICAL METHOD FOR ESTIMATION OF URINARY PREGNANEDIOL AND ALLOPREGNANEDIOL USING THIN LAYER CHROMATOGRAPHY

1965 ◽  
Vol 49 (1) ◽  
pp. 97-106 ◽  
Author(s):  
S. Sulimovici ◽  
B. Lunenfeld ◽  
M. C. Shelesnyak
Keyword(s):  
Melting Point ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Practical Method ◽  
Melting Point Determination ◽  
Uv Absorption Spectra ◽  
Infra Red ◽  
Point Determination ◽  
Layer Chromatography ◽  
Hydrolysis Of

ABSTRACT A method is described for the assay of urinary pregnanediol and allopregnanediol which employs acid hydrolysis of pregnanediol glucuronide, ascending thin-layer chromatography and spectrophotometric quantitation of the eluted pregnanediol and allopregnanediol. The reliability of the method was established by analysis of infra-red and UV absorption spectra, melting point determination, recovery experiments, duplicate assays and comparison with the Klopper method. The method has advantages in that it is rapid and requires small urine samples.

scholarly journals Acid Hydrolysis of Phenylthiohydantoins of Amino Acids

1971 ◽  
Vol 24 (4) ◽  
pp. 1247 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh
Keyword(s):  
Amino Acids ◽  
Hydrochloric Acid ◽  
Thin Layer ◽  
Acid Hydrolysis ◽  
Free Amino ◽  
Hydriodic Acid ◽  
Ultraviolet Spectroscopy ◽  
Quantitative Identification ◽  
Layer Chromatography ◽  
Hydrolysis Of

The phenylthiohydantoins (PTHs) derived from amino acids were hydrolysed in boiling hydriodic acid for 24 hr. Good yields of free amino acids were obtained for all PTH derivatives except methionine. In contrast to hydrolysis with hydrochloric acid, hydrolysis with hydriodic acid converts PTH-threonine, PTH-serine, and PTH-tryptophan respectively to oc-amino-n-butyric acid, alanine, and a mixture (approx. 2: 1) of glycine and alanine. This procedure provides a useful adjunct to thin-layer chromatography and ultraviolet spectroscopy for quantitative identification of the PTH derivative.

A Simple Nonchromatographic Determination of Glycerophosphatide in Serum

1969 ◽  
Vol 15 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Arthur F Rosenthal ◽  
Stella Ching-Hsien Han
Keyword(s):  
Thin Layer ◽  
Blood Serum ◽  
Methanol Extract ◽  
Periodic Acid ◽  
Lipid Mixture ◽  
Acid Reagent ◽  
Layer Chromatography ◽  
Chloroform Methanol ◽  
Good Agreement

Abstract Glycerophosphatide phosphorus is determined in ether-methanol extracts of blood serum by a nondigestive procedure which utilizes a sulfuric-periodic acid reagent. Sphingomyelin phosphorus is not liberated. The method shows good agreement with the sum of lecithin, cephalin, and lysolecithin phosphorus when the lipids are separated by thin-layer chromatography. Lecithin in an artificial lipid mixture is determined readily. The ether-methanol extraction gives results comparable to that of a standard chloroform-methanol extract.

Thin Layer Chromatographic Method for Analysis and Chemical Confirmation of Sterigmatocystin in Cheese

1980 ◽  
Vol 63 (1) ◽  
pp. 110-114 ◽  
Author(s):  
Hans P Van Egmond ◽  
Walter E Paulsch ◽  
Ellen Deijll ◽  
Pieter L Schuller
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Trifluoroacetic Acid ◽  
Quantitative Method ◽  
Chromatographic Method ◽  
Aspergillus Versicolor ◽  
Spray Reagent ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract A semi-quantitative method is described for the analysis of sterigmatocystin in cheese. The method is based on extraction of cheese with MeOH-4% KC1 (9+1), followed by Florisil and polyamide column cleanup and 2-dimensionaI thin layer chromatography (TLC). Visualization of sterigmatocystin on the TLC plates is enhanced by an ALCL3 spray reagent. The identity of sterigmatocystin is confirmed by a 2-dimensional TLC test based on reaction with trifluoroacetic acid (TFA) on the plate after first development. The reaction product formed is visualized by spraying with ALCL3. The method allows detection and confirmation of sterigmatocystin in cheese at concentrations as low as 5 μg/kg. The method has been applied to cheese samples ripening in warehouses and naturally molded with Aspergillus versicolor

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