Chemical composition of Argentinean propolis collected in extreme regions and its relation with antimicrobial and antioxidant activities

N. VERA, E. SOLORZANO, R ORDOÑEZ, L MALDONADO, E BEDASCARRASBURE, M I. ISLA

NATURAL PRODUCT COMMUNICATIONS

NATURAL PRODUCTS INC

Año: 2011 vol. 6 p. 823 - 827

1934-578X

This paper reveals, for the first time, the functional properties of propolis from an extreme region of Argentine (El Rinc¨®n,  province of Catamarca, Argentina), as well as the isolation and identification of bioactive compounds. The antioxidant activity was determined by ABTS method and ¦Â-carotene bleaching. The antibacterial activity was determined on methycillin resistant Staphylococcus aureus (MRSA) by the microdilutionmethod and bioautographic assays. Twelve compounds were isolated and identified by NMR. The main bioactive compounds were 2¡¯,4¡¯-dihydroxy-3-methoxychalcone (compound 3), 2¡¯,4¡¯-dihydroxychalcone (compound 9), 2¡¯,4¡¯,4-trihydroxy-6¡¯- methoxychalcone (compound 8), 5-hydroxy- 4¡¯,7-dimethoxyflavone (compound 4) , 4´,5-dihydroxy-3,7,8-trimethoxyflavone (compound 10) and 7-hydroxy- 5,8-dimethoxyflavone (compound 11). All compounds were active against clinical isolates (MIC50 10 ¦Ìg/ mL) and displayed antioxidant  activity (SC50 values of 20 ¦Ìg/mL). The MIC and SC50 values of the isolated compounds were lower than the values obtained with crude propolis extracts, chloroformic subextracts and isolated fractions. Our results show the biological activity of chalcones and flavonoids outside the phytocomplex.