Comparative study of the ethanol extracts of six Acinos Miller species: chemical composition, antimicrobial and antioxidative activities

Abstract

The ethanol extracts of selected Acinos Miller species were investigated in terms of chemical composition, antimicrobial and antioxidative activities. Qualitative and quantitative analyses of the extracts were performed using GC and GC-MS. Eighty-six constituents, accounting for 93.70-99.99% of the total composition of the extracts, were identified. The ethanol extracts of A. majoranifolius, A. suaveolens and A. alpinus were characterized by domination of monoterpenes, representing 85.03%, 57.39% and 28.02% of the total extracts, respectively. Fatty acids and their esters in the A. arvensis and A. graveolens extracts reached 28.97% and 30.75%. Also, n-alkanes were the major compounds found in A. hungaricus ethanol extract (30.98%). The extracts were characterized by determination of total polyphenols, flavonoids and tannins. Besides, the antioxidant activity of the investigated extracts was estimated by two assays: DPPH and FRAP test. The highest antioxidant activity was observed in the extract of A. alpinus which had high levels of all examined polyphenol classes. A disk diffusion method was employed for the determination of the antimicrobial activities of the ethanol extracts. Gram-positive: Bacillus subtilis, Sarcina lutea, Staphylococcus aureus, Clostridium pyogenes, Enterococcus sp., Micrococcus flavus; Gram-negative: Klebsiella pneumoniae, Pseudomonas aerugionsa, Salmonella enteritidis, Proteus vulgaris, Escherichia coli and fungal organisms: Aspergillus niger, Candida albicans and Saccharomyces cerevisiae were used as test microorganisms. The results of preliminary bioassay demonstrated that the A. alpinus ethanol extract could be a possible source of compounds with antioxidant and antimicrobial activity.