Antibacterial Activity of Silphium perfoliatum. Extracts

Abstract

Methanol and hexane extracts obtained from above-and below-ground organs of the cup plant Silphium perfoliatum. L. (Asteraceae) were analyzed by gas chromatography–mass spectrometry (GC-MS). Eighty-five components were identified in the extracts. Moreover, evaluation of the content of total secondary metabolites (flavonoids, o.-dihydroxyphenols, and glycoside-bonded oleanolic acid) was made in the methanol extract. It was found that leaf, inflorescence, and rhizome extracts of S. perfoliatum. were characterized by antibacterial action toward Gram-positive (Enterococcus faecalis., Staphylococcus aureus.) and Gram-negative (Escherichia coli., Pseudomonas aeruginosa. bacteria). All the extracts showed extremely high activity toward Staphylococcus aureus. FDA 209P strains (MIC values: 1.00 mg/mL for rhizome alcohol and hexane extracts; 2.50 mg/mL for leaf and inflorescence alcohol extracts and for leaf hexane extracts; 5.00 mg/mL for inflorescence hexane extracts). In general, alcohol extracts had slightly stronger antibacterial properties compared with lipophilic ones. Among the alcohol extracts, those made of S. perfoliatum. rhizomes had the highest activity compared with the leaf and inflorescence extracts.