Resumen

CALLE, Alberto et al. Evaluation of flavonoid contents and antibacterial activity of five Bolivian baccharis species. Rev. Bol. Quim [online]. 2017, vol.34, n.4, pp.112-122. ISSN 0250-5460.

Five Bolivian Baccharis species (Baccharis latifolia, B. papillosa, B. tola, B. pentlandii and B. boliviensis) used in the folk medicine were analyzed by UV/Vis spectroscopy and HPLC to evaluate the flavonoid contents. First, using aluminium chloride colorimetric method, the total flavonoids (TF) contents respect of Luteolin was determined, showing that B. latifolia (8,03 mg TF eq Lu/g of leaves) presents the major quantity of total flavonoids in their leaves. Furthermore, our studies indicate that the method used for extraction gives extracts with high concentration of flavonoids between 53,06 and 85,86 mg TF eq Lu/g of EE (Ethanolic Extract) and that this concentration is increased in the last Sephadex LH-20 fractions, giving contents between 260,43 and 397,12 mg TF eq Lu/g of EFS (Enriched Fraction by Sephadex). On the other hand, the HPLC profiles of those extracts showed that the B. latifolia extract is the most complex; while the simplest is the B. pentlandii extract. Finally, the antibacterial activity was evaluated by agar well diffusion method, against nine bacteria ATCC and one bacterium clinical isolate, determining that all the EE have activity against Staphylococcus aureus (ATCC 25923 sensible) and S. aureus (ATCC 29213 resistant), but the major activity was observed in B. tola EFS (65,2 % of inhibition against S. aureus ATCC 25923 sensible).

Palabras clave : Flavonoids; antibacterial activity; Baccharis latifolia; Baccharis papillosa; Baccharis boliviensis; Baccharis tola; Baccharis pentlandii.

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