Antimicrobial Activity of neo-Clerodane Diterpenoids isolated from Lamiaceae Species against Pathogenic and Food Spoilage Microorganisms.

Antimicrobial activity of nineteen neo-clerodane diterpenoids, isolated from the acetone extracts of the aerial parts of Scutellaria and Salvia species (Lamiaceae) were tested against thirteen strains belonging to nine different species of pathogenic and food spoilage bacteria Aeromonas hydrophila, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella abony and Staphylococcus aureus as well as against two yeast strains belonging to species Candida albicans. Seven of the evaluated compounds scutalpin A, scutalpin E, scutalpin F, salviarin, splenolide A, splenolide B and splendidin demonstrated antimicrobial activity against used test microbial strains, the rest of the compounds were inactive within the studied concentration range. Among all of the tested compounds the highest antimicrobial activity was detected for scutalpin A against Staphylococcus aureus (MIC 25 µg/mL).