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.
Ethnopharmacologically important but underestimated genus Sorbus: a comprehensive review
Sorbus L. sensu lato (Rosaceae family) comprises over 250 trees and shrubs growing in the Northern Hemisphere. Several Sorbus species have found their way into traditonal materia medica, as different leaf, bark or fruit preparations have a long-standing folk use. Ethnomedicine recommends their use not only in respiratory and gastrointestinal system disorders, but also in rheumatism, cancer or diabetes. Chemical composition of the genus Sorbus has been studied since 1960s and until now more than 250 compounds have been identified from thirty-eight species. The most thoroughly investigated substances are phenolic compounds (flavonoids and phenolic acids). Other constituents include triterpenes, sterols, carboxylic acids, coumarins and cyanogenic glycosides. Biological activity studies performed on the representatives of the genus Sorbus have been predominantly conducted on extracts prepared with the use of different solvents, and more rarely on isolated constituents. The majority of these studies were devoted to determination of antioxidant potential of Sorbus extracts. In a few cases targeted studies were conducted to confirm specific folk usage. Two of the fairly well documented medicinal uses are the antidiabetic activity of Sorbus decora and anti-inflammatory activity of Sorbus commixta.
Inhibition of Root Growth and Polyamine Metabolism in Sunflower (Helianthus annuus) Seedlings Under Cadmium and Copper Stress
Although sunflower is usually regarded as a highly tolerant crop, impairment of root growth at initial stages of plant development may result in poor crop establishment and higher susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on sunflower germination and initial root development, a pot experiment under controlled conditions was carried out. Possible involvement of polyamine metabolism in sunflower response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of these heavy metals showed significant inhibition of root growth, being this inhibition greater for Cd2+. Both metals caused significant increases in proline contents at the highest concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+ treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents at all concentrations assayed from the seventh day onward, causing no variations on this polyamine time-course pattern. Spermine and spermidine contents, however, were increased only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for Put increases under both metal treatments. This work demonstrates that initial root growth of sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also shows that polyamines are key biological compounds, which are probably involved in signaling pathways triggered under stress environmental conditions.