Triterpenoids from Brazilian Ilex species and their in vitro antitrypanosomal activity.

From the leaves of Ilex affinis and Ilex buxifolia, two adulterant species of "erva mate" (Ilex paraguariensis), three new triterpenoid glycosides were isolated. Affinoside 1 (3beta-O-[beta-D-glucopyranosyl-(1-->3)-[2-O-acetyl-(1-->2]]-alpha-L-arabinopyranosyl pomolic acid 28-O-beta-D-glucopyranosyl ester, 1) was isolated from I. affinis, while buxifolioside I (28-O-beta-D-glucopyranosyl ester of (20S)-3alpha,19alpha-dihydroxyurs-12-ene-23,28-dioic acid, 7) and buxifolioside II (28-O-beta-D-glucopyranosyl ester of (20S)-3beta,19alpha-dihydroxyurs-12-en-24,28-dioic acid, 8) were isolated from I. buxifolia. Along with these new compounds, ilexoside II (2), ursolic acid (3), 28-nor-ursolic acid (4), 3beta-O-acetylursolic acid (5), and uvaol (6) were also isolated. The observed results confirm the structural specificity of the I. paraguariensis triterpenoids and reinforce a previous proposal to detect mate adulteration by triterpenoid analysis. In addition, the in vitro antitrypanosomal activity of some Ilex triterpenoids is also reported.

Saponins from maté (Ilex paraguariensis) amd other South American Ilex species: ten years research on Ilx saponins

Ilex paraguariensis is widely used in South Brazil, Argentinna, Paraguay and Uruguay as a beverage (maté) and also as a traditional medicinal plant. During the past ten years, we have systematically studied the saponins of the leaves of genuine maté (Ilex paraguariensis) and the other Ilex species reported as adulterants, searching for chemical differences. Here we give a brief account of the elucidated saponin structures. Ilex paraguariensis and Ilex dumosa can be considered as saponin rich species, containing between 5-10 per cent of crude saponins in the leaves, in opposition to other species that showed a lower saponin content. All the saponins from Ilex paraguariensis leaves identified up to now are glycosides of ursolic or oleanolic acid. From Ilex dumosa, the most frequently quoted maté adulterant, we have isolated and elucidated the structures of ten saponins, almost all of them being glycosides of oleanolic acid and one of 29-hydroxyoleanolic acid. In comparison, the saponin pattern for the other South American Ilex species investigated up to now is different. The saponins from I. pseudobuxus, I. argentina, I. taubertiana and I. theezans all have the aglycones derived from the 19alpha-hydroxyursolic acid. Saponins containing this type of aglycone were not found in the leaves of Ilex paraguariensis and Ilex dumosa. These are important features, that may have taxonomical significance. Furthermore, this knowledge is necessary to develop methodologies for quality control of maté products and to identify the compounds involved in the tast, flavor and pharmacological properties.