Chemical Composition of Argentinean Propolis Collected

VERA, NANCY; SOLORZANO, RITA ELIANA; ORDÓÑEZ, ROXANA MABEL; MALDONADO, LUIS; BEDESCARRASBURE, ENRIQUE; ISLA, MARÍA INÉS

NATURAL PRODUCT COMMUNICATIONS

NATURAL PRODUCTS INC

Lugar: ----; Año: 2011

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 the ABTS method and ¦Â-carotene bleaching. The antibacterial activity was determined on methicillin resistant Staphylococcus aureus (MRSA) by the microdilution method and bioautographic assays. Twelve compounds were isolated and identified by NMR spectroscopy. The main bioactive compounds were 2¡¯,4¡¯-dihydroxy-3¡¯-methoxychalcone (3), 2¡¯,4¡¯-dihydroxychalcone (9), 2¡¯,4¡¯,4-trihydroxy-6¡¯- methoxychalcone (8), 5-hydroxy- 4¡¯,7-dimethoxyflavone (4) , 4´,5-dihydroxy-3,7,8-trimethoxyflavone (10) and 7-hydroxy- 5,8-dimethoxyflavone (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 those obtained with crude propolis extracts, chloroform sub-extracts and isolated fractions.