scholarly journals The inhibition of N-acetyl-β-d-glucosaminase by the (1→4)- and (1→5)-lactones of N-acetylglucosaminic acid

1970 ◽  
Vol 119 (2) ◽  
pp. 303-306 ◽  
Author(s):  
T. E. Couling ◽  
R. Goodey
Keyword(s):  
Paper Chromatography ◽  
Relative Stability ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Countercurrent Distribution

The inhibition of N-acetyl-β-d-glucosaminase activity by 2-acetamido-2-deoxy-d-gluconolactone was examined. Separation of the (1→4)- and (1→5)-lactones was achieved by using paper chromatography or countercurrent distribution and identification was obtained by examination of the relative stability of the components of separated material. Quantitative measurement of the two lactones was by kinetic titration or by a colorimetric method based on their reaction with hydroxylamine. It was shown that only the (1→5)-lactone acted as an inhibitor of N-acetyl-β-d-glucosaminase.

A COLORIMETRIC METHOD FOR MEASURING INDICAN

1960 ◽  
Vol 38 (3) ◽  
pp. 253-262 ◽  
Author(s):  
A. M. Marko ◽  
F. B. Reynolds
Keyword(s):  
Potassium Salt ◽  
Sodium Acetate ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Urine Samples ◽  
Review Of The Literature ◽  
Optimum Conditions ◽  
Qualitative Test ◽  
Colored Compound ◽  
Colored Reaction Product

A qualitative test for indican (indoxyl-O-sulphate, usually as the potassium salt) has been adapted for the quantitative measurement of indican. The method involves the condensation of indican and p-dimethylaminobenzaldehyde in the presence of acid to yield an orange-colored compound. When an excess of sodium acetate is added, the orange-colored reaction product is converted to a cherry-red derivative. The effects of time, acids, temperature, and concentration of reagents on the reaction have been studied and optimum conditions have been selected to obtain a standard curve.Unsatisfactory analytical results are obtained when this method is applied directly to urine samples and a method for the quantitative elution of indican from charcoal columns has, therefore, been devised. With this modification quantitative recoveries have been achieved with indican alone and with indican added to urine samples.In addition a review of the literature pertaining to indican measurement and indigoid pigments is presented.

Colorimetric Method for the Determination of Starch in Tobacco

1972 ◽  
Vol 55 (1) ◽  
pp. 209-213
Author(s):  
A J Sensabaugh ◽  
Kenneth L Rush
Keyword(s):  
Acid Treatment ◽  
Quantitative Measurement ◽  
Starch Content ◽  
Colorimetric Method ◽  
Colored Complex ◽  
Iodine Complex ◽  
Mesh Screen ◽  
Colorimetric Data ◽  
Tobacco Sample

Abstract A method is presented for extracting and determining the starch content of tobacco. Dried tobacco is ground to pass a 60 mesh screen, interfering colored materials are removed from the tobacco by a methanol-water extraction, and the starch is extracted from the tobacco by a perchloric acid treatment. Final quantitative measurement of the starch is made on a colored starch–iodine complex. The absorbance of this colored complex at 600 nm is proportional to the concentration of the starch in solution and can be related to the starch content of the original tobacco sample. Also included is a procedure for the isolation of pure tobacco starch. Such material was prepared for use as a calibration standard needed for the calculation of starch content of tobacco samples from the colorimetric data.

A COLORIMETRIC METHOD FOR MEASURING INDICAN

1960 ◽  
Vol 38 (1) ◽  
pp. 253-262
Author(s):  
A. M. Marko ◽  
F. B. Reynolds
Keyword(s):  
Potassium Salt ◽  
Sodium Acetate ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Urine Samples ◽  
Review Of The Literature ◽  
Optimum Conditions ◽  
Qualitative Test ◽  
Colored Compound ◽  
Colored Reaction Product

A qualitative test for indican (indoxyl-O-sulphate, usually as the potassium salt) has been adapted for the quantitative measurement of indican. The method involves the condensation of indican and p-dimethylaminobenzaldehyde in the presence of acid to yield an orange-colored compound. When an excess of sodium acetate is added, the orange-colored reaction product is converted to a cherry-red derivative. The effects of time, acids, temperature, and concentration of reagents on the reaction have been studied and optimum conditions have been selected to obtain a standard curve.Unsatisfactory analytical results are obtained when this method is applied directly to urine samples and a method for the quantitative elution of indican from charcoal columns has, therefore, been devised. With this modification quantitative recoveries have been achieved with indican alone and with indican added to urine samples.In addition a review of the literature pertaining to indican measurement and indigoid pigments is presented.

scholarly journals Spectrophotometric quantification of dolutegravir based on redox reaction with Fe3+/1,10-phenanthroline

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Swathi Naraparaju ◽  
Durai Ananda Kumar Thirumoorthy ◽  
Sunitha Gurrala ◽  
Asra Jabeen ◽  
Pani Kumar D. Anumolu
Keyword(s):  
Redox Reaction ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Dosage Forms ◽  
Control Analysis ◽  
Colored Complex ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Dosage Forms ◽  
Quality Control Analysis

Abstract Background A simple and sensitive spectrophotometric method was developed for the quantitative measurement of dolutegravir in pure form and pharmaceutical formulation. The present method was based on redox reaction between dolutegravir and ferric chloride, which upon complexation with 1,10-phenanthroline formed an orange-colored complex that showed absorption maximum at 520.0 nm. Results The developed method obeyed linearity in the concentration range of 40.00–140.00 μg/mL. The method was also validated as per International Council for Harmonization guidelines and the results were within acceptance values. The validated method was employed for the determination of dolutegravir in pharmaceutical dosage form and the percentage assay value was found to be 102.5, which is in agreement with its label claimed. Conclusion The developed redox-based colorimetric method could be used in the routine quality control analysis of dolutegravir present in various pharmaceutical dosage forms.

scholarly journals THE PURIFICATION OF HYPERTENSIN I

1954 ◽  
Vol 100 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Leonard T. Skeggs ◽  
Walton H. Marsh ◽  
Joseph R. Kahn ◽  
Norman P. Shumway
Keyword(s):  
Amino Acids ◽  
Nitrogen Content ◽  
Acid Hydrolysis ◽  
Paper Chromatography ◽  
Solid Acid ◽  
Specific Activity ◽  
Single Component ◽  
Countercurrent Distribution ◽  
Pressor Agent

The purification of hypertensin I has been described. The final product which is four times as powerful a pressor agent as l-arterenol, is obtained with an over-all recovery of 40 per cent. The product consists of a single component in countercurrent distribution, having a nitrogen content of 15.97 per cent and a specific activity of 7050 Goldblatt units per mg. of N or 1125 units per mg. of solid. Acid hydrolysis and paper chromatography indicate in a preliminary fashion that there are about nine amino acids present in the intact polypeptide.

Indoles in Uremia: Identification by Countercurrent Distribution and Paper Chromatography

1968 ◽  
Vol 21 (5) ◽  
pp. 436-450 ◽  
Author(s):  
GEORGE D. LUDWIG ◽  
DOROTHY SENESKY ◽  
L. W. BLUEMLE ◽  
J. RUSSELL ELKINTON
Keyword(s):  
Paper Chromatography ◽  
Countercurrent Distribution

SEPARATION OF ENDOMYCINS A AND B, AND THEIR IDENTIFICATION AS MEMBERS OF THE POLYENE GROUPS OF ANTIFUNGAL ANTIBIOTICS

1957 ◽  
Vol 35 (12) ◽  
pp. 1461-1466 ◽  
Author(s):  
L. C. Vining ◽  
W. A. Taber
Keyword(s):  
Absorption Spectra ◽  
Paper Chromatography ◽  
Ultraviolet Absorption ◽  
Countercurrent Distribution ◽  
Double Bonds ◽  
Active Components ◽  
Streptomyces Species ◽  
Antifungal Antibiotics

An unidentified Streptomyces species isolated from platings of "honey dew" of the fungus Clavicepspurpurea produced two antifungal antibiotics which were shown by paper chromatography to be identical with the two active components of endomycin, and also with helixins A and B. An examination of the ultraviolet absorption spectra of the three complexes showed maxima at wavelengths associated with two unsaturated systems containing four and six conjugated double bonds respectively. The two unsaturated components were separated by countercurrent distribution and shown to correspond to the two active fractions. The tetraene has been named endomycin A, and the hexaene endomycin B. Flavacid, a polyene complex also containing tetraene and hexaene components, is not identical with endomycin.

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