An investigation and identification of polysaccharides isolated from archeological specimens
SummaryPolymeric compounds have been isolated from archeological specimens (fragments of Central Asian paintings of the 2nd-19th centuries). A comparison of their IR spectra with the spectra of plant gums has shown that they are polysaccharides which have remained undestroyed for up to 1800 yr. In some cases it has been possible from the IR spectra and composition of the extracted polysaccharides to provisionally identify sourcherry or apricot gum, of which these polysaccharides were components.
Carbohydrates from Precambrian and Cambrian Rocks and Fossils
Carbohydrate residues in eleven samples of early to late Precambrian rocks and fossils and one sample of Middle Cambrian Burgess Shale ranged from traces to more than 5 μg/g Free monosaccharides and a disaccharide, acid-extractable (polymeric) sugars, and recognizable polysaccharides were found in the samples. Geological conditions in the sampling areas suggest that the free sugars, being water-soluble, may not be indigenous to the rock but perhaps were introduced by ground-water circulation during the present or a preceding erosion cycle. Available evidence suggests that the acid-extractable monosaccharides and polysaccharides are at least partly native to the rocks or fossils in which they occur.

The acid-extractable sugars obtained in these samples are β-D-galactose, β-D-glucose, mannose, arabinose, xylose, ribose, and rhamnose; the first two were identified enzymatically and they and the other sugars were also identified chromatographically. The polysaccharides found in these samples are linear α —1 →4 glucopyranose units suggesting starch, β — 1 → 4 glucopyranose units suggesting cellulose, and β — 1 → 3 glucopyranose unitssug-gesting laminaran. No starch residues were found n i the two lower Precambrian samples (Soudan and Coutchiching), but a trace of celluloseand laminaran was obtained in the Coutchiching. This may be an indication that cellulose-type structural polysac-charides and laminaran-type reserve sugars, but not starch-type food-reserve polysaccharides, existed in the early Precambrian.
Quantitative bestimmung tritiummarkierter verbindungen auf dünnschichtchromatogrammen
Zusammenfassung Es wird eine direkte quantitative Bestimmung von 3H auf Dunnschichtchromatogrammen durch kontinuierliche Auswertung mit Hilfe eines Methan-Durchfluss-Zahlrohres ublicher Bauart durchgefuhrt. Der Gesamtfehler dieser einfachen und schnellen Methode betragt 10–30%. Es wird die Abhangigkeit des Wirkungsgrades von der auf die Platte aufgetragenen Substanzmenge untersucht. Die Messausbeuten von 3H, 55Fe und 14C werden verglichen. Einige Beziehungen zwischen den Messgrossen und den Parametern der Messanordnung werden angegeben.