ß-Lactamase Inhibitors from Anacardium occidentale

Abstract

The antimicrobial activity of cashew nut shell liquid (CNSL) and anacardic acids isolated from nuts of Anacardium occidentale were tested against several strains responsible of cutaneous infection or olfactory disagreement. CNSL exhibited minimal inhibitory concentrations (MIC) against Propionibacterium acnes (1.56 µg/mL), Corynebacterium xerosis (6.25 µg/mL), and various strains of Staphylococcus aureus (25 µg/mL), but was not active against the fungus Pityrosporum ovale. The ß-lactamase inhibition was tested by the agar diffusion method with penicillin G, against two strains of S. aureus, both resistant to penicillin by synthesis of ß-lactamase, but one strain being insensitive to all ß-lactamines antibiotics due to a modification of protein linking penicillin (PLP 2a). The results showed clearly the ß-lactamase inhibitory activity of CNSL and anacardic acids on S. aureus enzyme, without activity on PLP 2a.