Antibacterial activity of prenylated benzopyrans from Peperomia obtusifolia (Piperaceae)

CUTRÓ, ANDREA CARLA; FURLAN, MAYSA; LÓPEZ, SILVIA NOELÍ; RUIZ MOSTACERO, NATHALIE; HOLLMANN, AXEL; VALLES, JULIETA; CASTELLI, MARÍA VICTORIA; BATISTA, JOÃO MARCOS; FULGUEIRA, CECILIA LUISA

NATURAL PRODUCT RESEARCH

TAYLOR & FRANCIS LTD

Año: 2019 p. 1 - 5

1478-6419

Peperomia obtusifolia is a herbaceous perennial plant native to the Americas reported as a traditional medicine to treat snake bites and as a skin cleanser. The bioassay-guided fractionation of crude extracts from aerial parts of P. obtusifolia against a panel of clinically important fungi and bacteria, showed that hexane and dichloromethane extracts demonstrated selective bacterial inhibition, allowing the isolation of the known compounds peperobtusin A (1), and 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3?-methyl-2?-butenyl)-2-(4?-methyl-1?,3?-pentadienyl)-2H-1-benzopyran-6-carboxylic acid (2) from dichloromethane extract. Compound 2 was active against Gram-positive bacteria including community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates and an Enterococcus faecalis vancomycin-resistant strain, with minimal inhibitory concentration (MIC) values of 4 μg/mL (10.8 μM) and 8 μg/mL (21.6 μM) respectively. The interaction of compound 2 with the bacterial membrane was demonstrated by means of Zeta potential experiments on S. aureus, then confirming the membrane damage by fluorescent microscopy experiments.