Assessment of the chemical composition and in vitro antimicrobial potential of extracts of the liverwort Scapania aspera.

The chemical composition of Scapania aspera extracts was determined by solid phase micro extraction gas chromatography-mass spectrometry (SPME GC-MS) and 96 constituents were identified. The dominant compounds in the methanol extract were beta-barbatene (25.1%), o-cymene (14.0%), alpha-barbatene (5.7%), allo-aromadendrene (4.9%) and beta-bourbonene, while in the ethanol extract, o-cymene (17.8%), beta-barbatene (17.6%), alpha-thujene (6.7%), octen-1-ol acetate (4.9%) and beta-bazzanene (2.4%) were the major components. In the ethyl acetate extract, beta-barbatene (14.3%), undecane (11.8%), 2-methyldecane (11.2%), decane (10.9%) and o-cymene (3.6%) were major components. The antimicrobial activity of the different extracts was evaluated against pathogenic and food spoilage microorganisms using disc diffusion and micro-broth dilution methods. The minimal inhibitory concentration (MIC) of extracts of S. aspera varied from 0.4 to 1.5 mg/mL and 1 to 3 mg/mL for yeast and bacterial strains, respectively. The zone of inhibition of the methanol extract for yeast strains was higher than that for bacterial strains. The results suggest that S. aspera extracts have potential as natural antimicrobial agents.