Talukder, M. Q-K.

2019-02-15T14:24:06Z

2019-02-15T14:24:06Z

1972

• 1. The thesis describes an investigation into the presence and quantities of four free, monosaccharides, L- arabinose, D-xylose, D-ribose and (presumably -) fucose in the urine of healthy human subjects and of patients suffering from renal failure. • 2. Two new quantitative analytical procedures based on one - dimensional thin-layer chromatography have been devised whereby it has become possible for the first time rapidly (3 h) to separate and measure at microgram levels, arabinose, ribose, xylose and fucose from the numerous other sugars present in urine from human subjects. On thin -layers of Kieselguhr G buffered with sodium acetate (acetate plate), arabinose and ribose are measured. On thin-layers of Kieselguhr G buffered with sodium dihydrogen phosphate (phosphate plate), fucose is determined. Xylose is measured by difference between ribose on an acetate plate and xylose plus ribose on a phosphate plate. Previously, only one complicated technique, occupying 5 days for the paper chromatography was available (Date, 1958a, 1958b, 1958c and 1966). • 3. The spraying reagents used to colour the sugar spots can detect qualitatively to the lowest limit of 0.5 μg of each sugar on the devised t.l.c. systems. The new PABA reagent visually distinguishes different sugar classes on the both t.l.c. systems. This reagent may be employed for quantitative measurements whereby linear relationship holds upto 30 μg for recovered colour of xylose from acetate plates and upto 80 μg for fucose from phosphate plates. Using the p-anisidine hydrochloride staining reagent, quantitative spectrophotometric determination of the extracted sugar spots is possible to the lowest limit of 2.5 μg for each sugar; linear relationship holds upto 8.0 dug for each sugar on either plate. • 4. Preparatory to chromatography, deionisation of urine samples is obligatory and accomplished by means of ion- exchange resins Amberlite IR-120 (H⁺) and Amberlite IRA -400 (acetate) using two glass columns in tandem. • 5. Specificity is conferred on the estimates by the comparable behaviours of the urinary aldopentoses and fucose so estimated and the authentic sugars on the thin-layer chromatograms. • 6. The separation of the sugars on the devised thin-layers is always reproducible. Quantitative reproducibilities (coefficient of variations) in a septuplicate analysis of the same urine sample show arabinose as 13.1%, xylose 15%, ribose 7.2% and fucose 10.2%. The mean±S.D. recoveries of 10-30 μg of arabinose, xylose, ribose and fucose added to the same urine samples in six experiments are 93%±5% (range 80-113%), 101%±41% (range 50-166 %), 95%±9% (range 85-110%) and 95%±14% (range 80-110%) respectively. • 7. All urine samples of six fasting healthy males and six fasting healthy females invariably contain arabinose, xylose, ribose and fucose. These sugars must presumably originate in endogenous processes. There is no significant difference in the excretion between the corresponding sugars in fasting state in two sexes. The mean fasting rates of excretion (,ig/min) of the sugars for the twelve subjects are 13.3±3.4 (arabinose), 8.5±1.9 (xylose), 5±1.5 (ribose) and 16.6±5.6 (fucose). • 8. Consuming an ample diet, free as far as possible from known sources of aldopentoses, healthy subjects at three different periods of the day excrete the sugars at rates unchanged from those in the fasting state. It is suggested that these sugars are excreted at constant rate independently of the urine volume. • 9. On diets potentially rich in aldopentoses, the subjects of (8) show increased rates of excretion of aldopentoses, mainly that of xylose and less so of arabinose. Noteworthy is the fact that rates of excretion of both ribose and fucose were not increased. • 10. Urines from all six patients with various forms of renal failure repeatedly show the same picture. Ribose is always excreted at the lower end of the normal range while arabinose, xylose and fucose, if detectable, are excreted only in unmeasurable amounts. • 11. The results are compared and discussed with other workers' findings. In so far as any reasonable suggestions can be made, the excretion of these four monosaccharides in health and in renal failure are discussed in the light of our knowledge of the somatic origins and metabolism of arabinose, ribose, xylose and fucose. The prospects of employing this technique and the measurements of these sugars in certain diseases are indicated.

http://hdl.handle.net/1842/34168

The University of Edinburgh

Annexe Thesis Digitisation Project 2019 Block 22

Study of the aldopentoses and fucose in human urine by thin-layer chromatography

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy