Polyprenylated benzophenone-enriched extracts obtained using SC–CO₂ from the dry ethanolic extract of Brazilian red propolis

ABSTRACT

Red propolis is a well-known potent antimicrobial source because of its various bioactive compounds. This work aims to submit a sample of Brazilian red propolis to supercritical CO₂ extraction, with subsequent chemical characterisation by HPLC and UHPLC–MS, and to evaluate the antifungal activity against three strains of Candida glabrata. The method proved to be selective for the extraction of benzophenones. The results demonstrated a correlation between the presence of benzophenones and antifungal activity. The supercritical extract that seems to be the richest in benzophenones was the one obtained with a pressure of 300 bar and was the most active against the C. glabrata strains.

Abbreviations: SFE, Supercritical Fluid Extraction; MIC, Minimal Inhibitory Concentration; SC, Supercritical; BZP, benzophenones

KEYWORDS:

• Brazilian red propolis
• supercritical extraction
• benzophenones
• antifungal activity

Acknowledgments

The authors are grateful to the Brazilian agencies CAPES, CNPq and FAPERGS for the financial support. Special thanks are given to Dr. M. Holzschuh (Analytic Central, Faculdade de Farmácia-UFRGS) for recording the UPLC-DAD-QTOF-MS analyses.