Abstract
One hundred and seventy seven acetone extracts of lichen and 258 ethyl acetate extracts of cultured lichen-forming fungi (LFF) were screened for antimicrobial activity against Staphylococcus aureus and Enterococcus faecium using a disk diffusion method. Divaricatic acid was isolated from Evernia mesomorpha and identified by LC-MS, 1H-, 13C- and DEPT-NMR. Purified divaricatic acid was effective against Gram + bacteria, such as Bacillus subtilis, Staphylococcus epidermidis, Streptococcus mutans, and Enterococcus faecium, with the minimum inhibitory concentration (MIC) values ranging from 7.0 to 64.0 μg/mL, whereas vancomycin was effective in the MICs ranging from 0.78 to 25.0 μg/mL. Interestingly, the antibacterial activity of divaricatic acid was higher than vancomycin against S. epidermidis and E. faecium, and divaricatic acid was active against Candida albicans. In addition, divaricatic acid was active as vancomycin against S. aureus (3A048; an MRSA). These results suggested that divaricatic acid is a potential antimicrobial agent for the treatment of MRSA infections.
Highlights
Lichens are composite living organisms comprised of algae and fungi or cyanobacteria [1,2], and produce numerous biologically active secondary metabolites with, for example, antiviral, antibiotic, antitumor, or anti-allergenic properties [3]
It was reported that antibacterial activity of usnic acid was primarily caused acid showed a high degree of Escherichia coli RecA inhibition, relating to SOS response in bacteria [31]
Divaricatic acid was isolated from the lichen E. mesomorpha and identified by liquid chromatography–mass spectrometry (LC-MS), 1 H, 13 C- and DEPT-NMR
Summary
Lichens are composite living organisms comprised of algae (photobiont) and fungi or cyanobacteria (mycobiont) [1,2], and produce numerous biologically active secondary metabolites with, for example, antiviral, antibiotic, antitumor, or anti-allergenic properties [3]. Gram-positive bacterium found in the human gastrointestinal proven efficacy against MRSA infections and has been administered even other treatments tract, have causes diseases, such as neonatal meningitis or endocarditis, and has recently emerged as a failed [16,17]. Tract, causes diseases, such as neonatal meningitis or endocarditis, and has recently emerged as a Divaricatic acid has been reported in extracts of the lichens Ramalina hierrensis [20], Flavocetraria therapeutically challenging pathogen [18,19]. Algerian lichens, such as Cladonia rangiformis, Ramalina farinaceae, R. fastigiata, and Roccella phycopsis, aspera was reported to have molluscicidal and antiparasitic activities [24], and that from Lecanora were reported to be active against human pathogenic fungi [23]. Evernia mesomorpha and investigated its antimicrobial activities, and its activities against MRSA and Candida albicans
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
