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.
Ozonation of polycyclic aromatic hydrocarbons in oil/water-emulsions: mass transfer and reaction kinetics.
The ozonation of highly condensed polycyclic aromatic hydrocarbons (PAH) was studied in oil/water-emulsions, which are comparable to poorly water-soluble PAH in industrial wastewaters and at contaminated sites. As there was a lack of knowledge about the ozonation in oil/water-emulsions, first the ozone mass transfer was studied and optimized from the gas to the water phase and from the water to the oil phase. The ratio of mass transfer and oxidation reaction was determined by the Hatta-number and revealed a slow, quasi homogeneous reaction of ozone with PAH inside the oil droplets. Because the ozone gas concentration had no influence under the optimized conditions, the selective PAH-ozonation could be described microkinetically by a direct ozone reaction of pseudo-first order regarding PAH-concentrations. The determined PAH mean reaction rate constants of 1.02 min(-1) in oil/water-emulsions are in the upper range as found for PAH dissolved in water. These results give a new insight into the ozonation in the three-phase systems and into the treatment of highly condensed, hardly biodegradable PAH.