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.
Thin-layer chromatographic analysis of sugar mixtures
Abstract Some general remarks are made concerning the difficulties experienced in the quantitative determination of the composition of complex sugar mixtures in solution. The application of thin-layer chromatography to this analytical problem is discussed. A technique for obtaining a satisfactory separation of nine to ten sugars has been worked out. Methods of determining reducing sugars and keto-sugars in amounts of 0 to 100 μg are mentioned, as well as a technique for removing the sugar-containing area from the thin-layer plate. Figures illustrating the quantitative aspects of the method are given.
Phorbic Acid biosynthesis in the latex vessel system of euphorbia.
Evidence is presented that phorbic acid is formed in the latex producing cell system, rather than in photosynthetic or chlorophyll-free tissues of Euphorbia resinifera Berg. When a branch of the plant was kept first in a (14)CO(2) atmosphere with 12 hr light-dark periods for 2 days and then left under natural conditions in the air outside for at least 2 to 3 days, radioactive phorbic acid was found in the latex. Phorbic acid synthesis appeared to be independent of the photosynthetic and respiratory activities of the plant.Besides phorbic acid 2 other major radioactive compounds were recognized in the latex, a glycoside or oligosaccharide, and a lipid belonging to the group of triterpenoid compounds characteristic of the latex in several species of Euphorbia.