Abstract

Nassauvia dentata Griseb. (Asteraceae), is distributed from the mountain range in the Bío Bio region to Magallanes region in Chile. In this investigation, an antioxidant effect evaluation of N. dentata leaves and stems was performed with 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical and 2,2-Diphenyl-1- picrylhydrazyl (DPPH) free radical, expressed in equivalents. The concentration of the methanolic extract obtained from N. dentata (MEN), required to inhibit 50% of ABTS absorbance and DPPH absorbance (IC50 value), was calculated..In a kinetic assay performed with ABTS and determined with the IC50 value of 0.737 mg mL-1, the maximum effect was detected after 30 minutes (min), with an inhibition of 96.44 ± 2.44%. DPPH kinetic assay was made with the IC50 value of 1.562 mg mL-1 and after 20 min it was observed the maximum point of inhibition level, of 79.92 ± 3.39%. Consequently the assay of total polyphenols (TP) was determined according to the Folin-Ciocalteu method. Also phytochemical assays were made to recognize the secondary metabolites, present in the plant material and in MEN. A bigger presence of tannins, anthraquinones heterosides, steroid derivatives, coumarins, and flavonoids were found. Evaluation of the antifungal effect assay was made using different concentrations of MEN against Rhizoctonia solani Kühn (Ceratobasidiaceae). It was possible to determine the maximum inhibition level of growing of the mushroom at 20 mg mL-1 of MEN concentration, on average 77 percent. The results of the present study indicate the presence of polyphenols in this plant, and might be considered as a source of bioactive compounds.