Antimicrobial and anti-lipase activity of quercetin and its C2-C16 3-O-acyl-esters

Quercetin (Q) and 3-O-acylquercetines, up to 100 microg/mL, did not show significant activity on selected gram-positive strains, gram-negative strains and yeasts. Conversely an interesting inhibitory activity on Candida rugosa lipase by Q and its esters (3-O-acylquercetines) which, in vivo, could play an important role against lipase producing microorganisms, was detected. In particular, 3-O-acyl-quercetines, being more active (IC(16)=10(-4)-10(-6) M) and more lipophilic, could be more effective than Q when applied to the skin or mucosae