Presencia de metabolitos secundarios en el follaje de diez le?osas de ramoneo en el bosque xerofítico del chaco árido argentino

摘要

Presence of secondary metabolites (tannins, alkaloids, saponins and steroids) in the foliage of ten woody species of the Argentinean Arid Chaco Region was determined. Selected species were: Aspidosperma Quebracho-blanco; Prosopis flexuosa; Prosopis torquata; Bulnesia foliosa; Celtis pallida; Lippia turbinata; Larrea divaricata; Larrea cuneifolia; Acacia aroma and Mimozyganthus carinatus. These species are consumed by goats and cattle in the silvopastoral system of this region. Foliage samples were gathered in Autumn, Spring and Summer. At each time of the year, 35 samples from each species (leaves and petioles) were obtained and used to determine the qualitative presence of secondary metabolites. In general, a high proportion of plants had these four groups of secondary metabolites. In most of the cases, the metabolites were associated among them. Steroids were the most abundant, they were detected in all species, were the only secondary metabolite in some samples of P. torquata, A. aroma and C. pallida. Tannins were second in abundance. Although due to their effects on animal production, they could be the more important among the four. Saponins were placed in third position in order of presence. Finally, alkaloids were detected only in two species: P. flexuosa and A. quebracho-blanco.