Spectrophotometric Method for Quantitative Evaluation of Early Stages of Hydrolyses of Branched Components of Starches by α-Amylases

Dyk, John W. Van; Caldwell, M. L.

doi:10.1021/ac60111a007

Cited by 5 publications

(2 citation statements)

References 22 publications

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“…The starch contents of flotation liquors, however, are difficult to determine with the existing chemical methods (2, 3, 13, 20), because the liquors are frequently contaminated with organic and inorganic species. Under such a condition, ultraviolet spectrograms (24) become difficult to interpret, as so many materials absorb here. Colorimetric methods (9,19,25) suffer similarly, and polarimetric techniques (1,6) are tedious.…”

Section: Starchesmentioning

confidence: 99%

Polarographic Estimation of Starch and Its Application in Flotation

Sun¹,

Love²,

Holzmann³

1958

Anal. Chem.

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Section: Starchesmentioning

confidence: 99%

Polarographic Estimation of Starch and Its Application in Flotation

Sun¹,

Love²,

Holzmann³

1958

Anal. Chem.

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“…This was carried out by measurement of the decrease in iodine staining power of British Drug Houses Ltd. soluble starch (cf. Van Dyk & Caldwell, 1956). pH optima of enzymes.…”

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confidence: 99%

Studies on carbohydrate-metabolizing enzymes. 12. A survey of the carbohydrases of alfalfa

Manners¹

1964

Biochemical Journal

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The presence of a number of carbohydrases in alfalfa (lucerne, Medicago sativa) seeds and seedlings has been reported, including o-D-glucosidase, aD -galactosidase, fl-D-fucosidase, P-N-acetyl-Dglucosaminidase (Levvy & McAllan, 1962), f-Dglucosidase, ,B-D-galactosidase and M-D-mannosidase (Hill, 1934; Levvy & McAllan, 1962). A comparative study of almond and alfalfa 'emulsins' has also been made (Hill, 1934). Studies of the mature plant appear to be limited to the pectinesterase activity (Lineweaver & Ballou, 1945; MacDonnell, Jansen & Lineweaver, 1945; Mac-Donnell, Jang & Jansen, 1950). In most previous studies, glycosidase activities were tested against synthetic and natural glycosides with non-carbohydrate aglycones. A survey of the oligosaccharideand polysaccharide-degrading enzymes has now been undertaken with a view to the assessment of their possible use in the structural analysis of alfalfa components. The carbohydrases probably bear some relation to the carbohydrate components of the plant. Apart from the reserve galactomannan of the seed (Hirst, Jones & Walder, 1947; Courtois, Anagnostopoulos & Petek, 1958), and the pectic substances and hemicellulose of the mature plant (Aspinall & Fanshawe, 1961; Myhre & Smith, 1962), little is known of the high-molecular-weight components of alfalfa. Small quantities of starch are present in the leaves of the plant (Hirst, Mackenzie & Wylam, 1959), though this is likely to show a marked diurnal variation, as in the related clover (Bailey, 1958). Fructosans, which form the main carbohydrate reserves of grasses, appear to be absent (Hirst et al. 1959). The raffinose-stachyose series of oligosaccharides, together with sucrose, appear to comprise the oligosaccharide component in alfalfa (Aspinall & Fanshawe, 1961; Meunie, 1936). EXPERIMENTAL Material8 Plant material. Medicago sativa var. de Puits was used. Seed8. These were purchased from Elsom Ltd., Spalding, Lincs., and were untreated. * Part 11: Cunningham & Manners (1964). 35 Seedlings. This term refers to seeds that had been steeped overnight in water and then stored, moist, in a layer 0 5 cm. thick between four sheets of Whatman no. 3 filter paper for 4 days, at 260, in the dark. For the preparation of seedling extract S, the seeds were steeped in water containing benzyl penicillin (6 mg./l.), streptomycin sulphate (10 mg./l.) and Mycostatin suspension (2 ml./I.) (E. R. Squibb and Sons, Speke, Liverpool), and the sheets of paper were also moistened daily with this solution. Leaf and stem tissue. Alfalfa was cut on

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STUDIES ON CARBOHYDRATE-METABOLIZING ENZYMES Part XXV. THE DEBRANCHING ENZYME SYSTEM IN GERMINATED BARLEY

Manners¹,

Rowe²

1971

Journal of the Institute of Brewing

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Extracts of germinated barley contain two debranching enzymes which have been separated from each other, and from α‐amylase, by continuous electrophoresis followed by gel filtration. Amylopectin 6‐glucanohydrolase hydrolyses the outer‐most inter‐chain linkages in amylopectin but has no action on glycogen or on α‐limit dextrins. Limit dextrinase has no action on amylopectin, but readily hydrolyses α‐limit dextrins; it differs fron amylopectin 6‐glucanohydrolase in having a relatively lower activity at pH 4, pH 7 or 60° C, and is selectively activated by chloride ions.

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Spectrophotometric Method for Quantitative Evaluation of Early Stages of Hydrolyses of Branched Components of Starches by α-Amylases

Cited by 5 publications

References 22 publications

Polarographic Estimation of Starch and Its Application in Flotation

Polarographic Estimation of Starch and Its Application in Flotation

Studies on carbohydrate-metabolizing enzymes. 12. A survey of the carbohydrases of alfalfa

STUDIES ON CARBOHYDRATE-METABOLIZING ENZYMES Part XXV. THE DEBRANCHING ENZYME SYSTEM IN GERMINATED BARLEY

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