Ursolic acid inSorbus aucuparia
chromatographed on A1203, a mixture of neutral substances was obtained with the absorption bands in the IR spectrum characteristic for anhydrides (1805, 1734, and 1000 cm" 1) [3], which disappeared after the saponification of this mixture with 0.5 N ethanolic KOH at 40" C (figure, b). Pure abietic acid was extracted from the saponification product. Under the conditions mentioned, esters of the resin acids (if they are present in the mixture) are not saponified and therefore the acid was produced by the saponification of the anhydride.
Triterpene, IX. Über die Triterpene aus der Rinde von Sambucus nigra L. und die Darstellung von 3-epi-Ursolsäure
Die Isolierung von Ursolsaure (als Methylester), Betulin, α-Amyrin, β-Sitosterin, Cerylalkohol und n-Heptacosan aus der Rinde von S. nigra L. sowie die Darstellung von 3-epi-Ursolsaure und einigen Derivaten werden beschrieben.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.