A Modified Procedure for the Separation of Acidic Amino Compounds Using a Sulfonated Polystyrene Resin

Hamdy, M. K.; Harper, W. J.; Weiser, H. H.

doi:10.3168/jds.s0022-0302(55)94952-3

Cited by 12 publications

(8 citation statements)

References 11 publications

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“…The general procedure was similar to that of Moore and Stein (1951). Glutamine and asparagine were chromatographed on Zeo-Karb 225 by the method of Sims (1958), based on that of Hamdy, Harper and Weiser (1955)-Ethylene diaminetetra-acetic acid was not added to the buffer solutions, since it would interfere with N determinations.…”

Section: Chromatographic Separation Of Amino Acidsmentioning

confidence: 99%

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1961

New Phytologist

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A study has been made of the assimilation of ammonium salts by young barley seedlings grown under controlled conditions in water culture. The synthesis of amino acids, amides and proteins in the roots was traced by means of isotopic labelling with i^N. Chromatographic analysis on ion-exchange resins was used to separate the free and combined amino acids of the root tissues. There was evidence of the synthesis of proteins in the roots under the experimental conditions. After short periods of assimilation, the soluble amides and amino acids, especially glutamine and glutamic acid, were highly labelled with i^N, indicating a rapid synthesis of these constituents. Subsequently, the abundance of i^N in the amino acids combined in the root proteins showed a marked increase. The data are consistent with the occurrence of an e.xtensive synthesis and interconversion of amino acids and their utilization as precursors in the synthesis of proteins. The importance of glutamic acid and glutamine in the assimilation of nitrogen and synthesis of amino acids is shown by the rapid incorporation of ^-'N into both the amide and amino groups. Other amino acids are more slowly labelled and may be formed secondarily by transamination or interconversion. y-Aminobutyric acid appears to play a significant part in the metabolism of the roots, since it is formed at an early stage of assimilation. The labelling of y-aminobutyric acid with i^N indicates that, in barley seedlings, it is a secondary product, rather than a precursor of glutamic acid or glutamine.

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Section: Chromatographic Separation Of Amino Acidsmentioning

confidence: 99%

Untitled

1961

New Phytologist

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“…Other chromatographic methods were also developed or adapted in subsequent years and applied to cheese and other dairy products, including ion-exchange chromatography for free amino acids (Hamdy et al 1955), paper chromatograph for carbonyl compounds (Bassett & Harper 1958, Harper & Bassett 1958, and our first attempt at a gas chromatographic (GC) method for fatty acids and amines in a homemade gas chromatograph that used an automatic titrimeter as the detector (Hankinson & Harper 1958, Cole et al 1961). …”

Section: Other Methods Development Workmentioning

confidence: 99%

A Promise Kept

Harper

2010

Annu. Rev. Food Sci. Technol.

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This article is largely biographical and relates to my experiences of the past 67 years in research and teaching, both of equal importance in my life. I was fortunate to start at the beginning of the development of instrumental methods of analysis and have eagerly embraced each new methodology as it became available. This paper is dedicated to all those students and colleagues who taught me much and whose efforts are mainly responsible for what has been accomplished in our work with food science and technology. The research focused primarily on trying to find out the "why" behind the problems that food, and especially the dairy products area, encountered over the past 65 years. The teaching has tried to foster thinking and problem solving.

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“…At the same time, other chromatographic methods were being developed or adapted and applied to cheese and other dairy products included ion exchange chromatography for free amino acids (22)(23)(24)(25), paper chromatograph for carbonyl compounds (24-29) and our first attempt at a gas chromatographic (GC) method for fatty acids and amines in a home made GC that used an automatic titrimeter as detector, as shown in Figure 2. Work was instituted on the application of radioactive labeled compounds to begin to understand some of the mechanisms involved in cheese ripening, using a simple cheese slurry system to facilitate the use of the radioactive C 14 labeled compounds (24).…”

Section: -1959mentioning

confidence: 99%

Sixty Years of Research Associated with Flavor in Dairy Foods

Harper

2007

ACS Symposium Series

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A Modified Procedure for the Separation of Acidic Amino Compounds Using a Sulfonated Polystyrene Resin

Cited by 12 publications

References 11 publications

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Untitled

A Promise Kept

Sixty Years of Research Associated with Flavor in Dairy Foods

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