Phytomedicine 19 (2012) 1166–1172 Contents lists available at SciVerse ScienceDirect Phytomedicine jou rn al hom epage: www.elsevier.de/phymed Chemical composition of three Parmelia lichens and antioxidant, antimicrobial and cytotoxic activities of some their major metabolites Nedeljko Manojlovi ´ c a , Branislav Rankovi ´ c b , Marijana Kosani ´ c b,∗ , Perica Vasiljevi ´ c c , Tatjana Stanojkovi ´ c d a Department of Pharmacy, Medical Faculty, University of Kragujevac, 34000 Kragujevac, Serbia b Department of Biology, Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia c Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niˇ s, 18000 Niˇ s, Serbia d Institute of Oncology and Radiology of Serbia, 11000 Belgrade, Serbia a r t i c l e i n f o Keywords: Lichens HPLC-UV Chemical composition Biological activities a b s t r a c t The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia caperata, P. saxatilis and P. sulcata and antioxidant, antimicrobial and anticancer activities of some their major metabolites. The phytochemical analysis of acetone extracts of three Parmelia lichens were determined by HPLC-UV method. The predominant phenolic compounds in these extracts were proto- cetraric and usnic acids (P. caperata) and depsidone salazinic acid (other two species). Besides these compounds, atranorin and chloroatranorin, were also detected in some of these extracts. Antioxi- dant activity of their isolated metabolites was evaluated by free radical scavenging, superoxide anion radical scavenging and reducing power. As a result of the study salazinic acid had stronger antioxi- dant activity than protocetraric acid. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. Both compounds were highly active with minimum inhibitory concentration values ranging from 0.015 to 1 mg/ml. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Salazinic acid and protocetraric acid were found to be strong anticancer activ- ity toward both cell lines with IC 50 values ranging from 35.67 to 60.18 g/ml. The present study shows that tested lichen compounds demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggest that these lichens can be used as new sources of the natural antimicrobial agents, antioxidants and anticancer compounds. © 2012 Elsevier GmbH. All rights reserved. Introduction Lichens are complex symbiotic associations between a fun- gus (mycobiont) and photobiont which can be either an alga or cyanobacteria (Bates et al. 2011). They are proven as the earliest colonizers of terrestrial habitats on the earth with a worldwide distribution from artic to tropical regions and from the plains to the highest mountains. Their specific, even extreme, conditions existence, slow growth and long life are the reason for producing of numerous protective compounds against different physical and biological influences (Mitrovi ´ c et al. 2011). Lichens synthesize a variety of secondary metabolites, mostly from fungal metabolism. They are crystals deposited on the surface of hiphes. They are poorly soluble in water and can usually be ∗ Corresponding author. Tel.: +381 34336223; fax: +381 34335040. E-mail address: marijanakosanic@yahoo.com (M. Kosani ´ c). isolated from a lichen by organic dilutants (Otzurk et al. 1999). More than one hundred secondary metabolites, mainly monoaromatics, depsides, depsidones, pulvinates, dibenzofurans, anthraquinones and xanthones, characteristic of lichen have been detected and isolated (Molnar and Farkaˇ s 2010). Chemicals structures of these classes of compounds are similar and identification is often very difficult.For a long time, some lichen species have been used in tra- ditional medicine in the treatment of numerous infectious diseases (Bown 2001). The use of lichens in medicine is based on the fact that they contain unique and varied biologically active substances. Lichen substances exert a wide variety of biological actions including antibiotic, antimycotic, antiviral, anti-inflammatory, analgesic, antipyretic, antiproliferative and cytotoxic effects (Kosani ´ c et al. 2012a; Manojlovi ´ c et al. 2010). Thus, the aim of the present work was to identify of secondary metabolites of P. caperata, P. saxatilis and P. sulcata by HPLC-UV and to evaluate the antioxidant capacity, antimicrobial and anticancer activities of the acetone extracts from this lichen as well as their major secondary metabolites. 0944-7113/$ – see front matter © 2012 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.phymed.2012.07.012