Antimicrobial Activities of Extracts and Isolated Coumarins from the Roots of Four Ferulago Species Growing in Turkey

Ferulago species have been utilized since ancient times as digestive, sedative, aphrodisiac, along with in salads or as a spice due to their special odors. The study reports isolation and characterization of bioactive compounds of Ferulago pachyloba (F. pachyloba), Ferulago trachycarpa (F. trachycarpa), Ferulago bracteata (F. bracteata), and Ferulago blancheana (F. blancheana) via bioassay guided fractionation and isolation process. The structures of compounds were elucidated by detailed spectroscopic analyses. They were also assessed for their activities at 1000-31.25 µg/mL concentrations by microbroth-dilution methods. Antimicrobial activity of aqueous, methanol extracts and dichloromethane, ethyl acetate, n-butanol and aqueous residue fractions of methanol extracts from aerial parts and roots of species along with isolated compounds [osthole, imperatorin, bergapten, prantschimgin, peucedanol-2'-benzoate, grandivitinol, suberosin, xanthotoxin, felamidin, marmesin, umbelliferone, ulopterol and a sterol mixture consisted of stigmasterol, β-sitosterol] were evaluated. Antimicrobial effect has been seen against Gram-negative, Gram-positive bacteria, and a yeast C. albicans at a concentration between 31.25 and 62.5 μg/mL. Especially, C. albicans (MIC = 31.25 μg/mL) was the most inhibited microorganism. Moreover, growth of P. aeruginosa, B. subtilis, E. coli, and S. aureus were inhibited at 62.5 μg/mL MIC values. Among tested samples prantschimgin and dichloromethane fraction of aerial parts from F. pachyloba showed the best activity against C. albicans (MIC = 31.25 μg/mL). However, among aqueous extracts and residue fractions, only F. blancheana aerial parts, F. trachycarpa aerial parts, and roots and F. bracteata roots showed activity against C. albicans. Among microorganisms E. coli was found to be the least affected.

Keywords: Antimicrobial; Coumarin; Ferulago; Peucedanol-2′-benzoate; Prantschimgin.