title: Antimicrobial activity of the essential oil of Glossogyne tenuifolia against selected pathogens.
abstract: BACKGROUND
  Glossogyne tenuifolia (GT) is a perennial herb widely distributed in the areas from south Asia to Australia. Many biological effects of G. tenuifolia have been reported; however, the information about antimicrobial activity of the essential oil (EO) of the herb remains unavailable. Therefore, the aims of this study were to investigate the antimicrobial activity of the GT-EO in vitro and food systems, the antimicrobial impact (AI) of its individual compounds, and interactive effects of major active compounds (linalool, 4-terpineol, α-terpineol, ρ-cymene) on selected Gram-positive (S. aureus, L. monocytogenes, S. mutans and S. sanguinis) and Gram-negative (E. coli O157:H7, V. parahaemolyticus and S. enterica) pathogens.
  
  
  RESULTS
  The minimal microbicidal concentration (MMC) of the GT-EO ranged from 0.75 to 12 mg mL(-1) against the test bacteria in vitro. Except for L. monocytogenes, the GT-EO exhibited more inhibitory effect on the selected Gram positive than against the Gram negative bacteria at the GT-EO concentrations ≤ 12 mg mL(-1) . The interactive effects of major active compounds (linalool, 4-terpineol, α-terpineol, ρ-cymene) are additive instead of synergistic via the checkerboard analysis. The bacteria with a microbial load of ca. 10(2) CFU mL(-1) in the milk tea could be completely inactivated by the GT-EO with the MMC of 1.5 mg mL(-1) .
  
  
  CONCLUSIONS
  ρ-Cymene is the largest component in the GT-EO; however, it is not the compound predominantly affecting the entire antimicrobial activity of the EO. Instead, 4-terpineol is the most influential among the test compounds that contribute to the antimicrobial activity of the GT-EO.
authors.affiliation: Department of Cosmeceutics, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 40402, Taiwan.
authors.forename: Tsung-Shi
authors.initials: TS
authors.lastname: Yang
authors.forename: Louis Kuo-Ping
authors.initials: LK
authors.lastname: Chao
authors.forename: Tai-Ti
authors.initials: TT
authors.lastname: Liu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D001419:Bacteria / Q000187:drug effects*; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D009822:Oils, Volatile; D010938:Plant Oils
keywords: Glossogyne tenuifolia; antimicrobial activity; antimicrobial impact; essential oil; interaction; pathogens