Akademik Veri Yönetim Sistemi
Turk Hijyen ve Deneysel Biyoloji Dergisi, cilt.69, sa.3, ss.127-134, 2012 (Scopus)
Objective: Usnic acid extracted from Squamarina lentigera was tested for antimicrobial activities against seven bacteria including Bacillus megaterium, B. subtilis, Enterococcus faecalis (RSKK 508), Escherichia coli (ATCC 35218), Proteus mirabilis (Pasteur Ens. 235), Pseudomonas aeruginosa, Staphylococcus aureus, and usnic acid concentrations of this lichen species was determined. Method: 0.05 g of thalli of S. lentigera was added into 10 mL acetone and left for exraction at room temparature for 1 h. We used agar diffision method for screeening antimicrobial activity of usnic acid in this lichen species. In addition, the quantitative analysis of usnic acid in this lichen species was achieved by using HPLC. Identification of peaks in chromatograms of lichen extract is achieved by comparison of retention times with that of standart usnic acid. Results: The usnic acid extracts of S. lentigera were effectively active lichen extracts, and showed the highest inhibition effect on B. megaterium and B. subtilis. When the inhibition zones obtained from S. lentigera was compared with that of standard antibiotic, E. coli seems to be more susceptible to the lichen extract. Acetone extract of examined lichen species inhibited the growth of all tested Gram positive bacteria, with the exception of S. aureus. B. subtilis seems to be sensitive to the acetone extracts of examined lichen species. The solvent controls did not show any activities against the bacteria. The amounts of usnic acid in the acetone extracts of S. lentigera were determined as 2.47%. Conclusion: Our results demonstrating significant antimicrobial effects of S. lentigera, which are a contribution to the literature. This might explain the correlation between usnic acid concentration and antimicrobial activity. Results show an increase of antimicrobial acitivities by the increase of the amount of usnic acid concentration. The present study is the first paper on usnic acid concentration and antimicrobial activity of S. lentigera, which could be attracting for medicinal or pharmacological products.