Diversity analysis and associated antimicrobial activity of essential oil in Pyrrosia petiolosa.

The continued development of folk medicine to potentially treat infectious diseases has resulted in an increase in natural sources of antimicrobial agents, particularly the use of plant essential oils containing volatile products from secondary metabolism. The objectives of this investigation were to (i) analyze the chemical components of essential oils using GC-MS, and (ii) to examine their in vitro  antimicrobial activities against four strains of bacteria ( Staphylococcus aureus, Bacillus subtilis, Escherichia coli  and Shigella fiexneri ) and one fungus (Candida albicans ) by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) in liquid and solid media, respectively, from different Pyrrosia petiolosa  locations. Eighty-eight evaporable compounds were confirmed in their essential oils; the major components in the oils were 2,4-pentadienal (12.5%), phytol (10.5%) and nonanal (8.6%). Based on hierarchical cluster analysis, Pyrrosia  samples were categorized into four groups, indicating significant essential oil diversity from different Pyrrosia  locations. Results also indicated that essential oils had a broad-spectrum of antibacterial activities, particularly against Shigella fiexneri  and Staphylococcus aureus  with MICs of 5 μL/mL. Results from this investigation are the first to record the chemical component and antimicrobial potential of essential oils from different P. Petiolosa  locations.