Lichens secondary metabolites

Ecophysiology and Potential Modes of Action for Selected Lichen Secondary Metabolites... 

Lauterwein, M., Oethinger, M., Belsner, K., Peters, T., and Marre, R., 1995. In vitro activities of the lichen secondary metabolites vulpinic acid, (+)-usnic acid and (-)-usnic acid against aerobic and anaerobic microorganisms. Antimicrob. Agents Chemo. 39, 2541-2543. 

Dailey, R.N., D.L. Montgomery, J.T. Ingram, et al. 2008. Toxicity of the lichen secondary metabolite (+)-usnic acid in domestic sheep. Vet. Pathol Online 45(1)-.19. 

Springer Intranational Publishing Switzerland 2015 B. Rankovic (ed.). Lichen Secondary Metabolites, DOI 10.1007/978-3-319-13374-4 l... 

Once formed, the lichen secondary metabolites appear to be extremely stable. Very old herbarium specimens of lichens show no significant reduction in concentrations of lichen substances (Rundel 1978). In addition, the production of secondary compounds is genetically controlled (Culberson and Culberson 2001) and, in some instances, is correlated with the morphology and geography in individuals at the species and genus levels (Egan 1986 Zhou et al. 2006). 

Studies have also demonstrated that the production and/or content of secondary metabolites in lichens varied with changes in elevation. For example, it has been reported for Umbilicaria americana that lichen secondary metabolite production decreases with increasing elevation (Swanson et al. 1996). In contrast, Rubio et al. (2002) found increasing levels of rhizocarpic acid in Acarospora schleicheri with increasing elevation. The direct effects of elevation on the production of phenolic compounds by lichens may in fact be complicated by the dynamic interaction of various environmental factors. 

Lichen secondary metabolites are derived from three chemical pathways acetate-polymalonate pathway, shikimic acid pathway and mevalonic acid pathway (Fig. 1.3). 

Lichen Secondary Metabolites of the Acetate-Polymalonate Pathway... 

Application of Lichen Secondary Metabolites in Medicine and Pharmacy... 

Lichen secondary metabolites exhibit antimicrobial, antioxidant, antiinflammatory, cytotoxic, analgesic, antipyretic and antiviral properties (Table 1.1) and could be potential sources of pharmaceutically useful chemicals. Several examples are described below. 

Backorova M, Jendzelovsky R, Kello M et al (2012) Lichen secondary metabolites are responsible for induction of apoptosis in HT-29 and A2780 human cancer cell lines. Toxicol In Vitro 26 ... 

Molnar K, Farkas E (2010) Current results rai biological activities of lichen secondary metabolites. Z Naturforsch C 65 157-173... 

Lichen Secondary Metabolites as Potential Antibiotic Agents... 

Maciag-Dorszydska M, Wggrzyn G, Guzow-Krzeminska B (2014) Antibacterial activity of lichen secondary metabolite usnic acid is primarily caused by inhibition of RNA and DNA synthesis. FEMS Microbiol Lett 353 57-62... 

Studies on Antioxidant Properties of Lichen Secondary Metabolites 111... 

Mastan A, Sreedevi B, Kumari J et al (2014) Evaluation of the in vitro antioxidant and antibacterial activities of secondary metabolites produced from lichens. Asian J Pharm Clin Res 7 193-198 Melo MG, dos Santos JP, Serafini MR et al (2011) Redox properties and cytoprotective actions of atranoiin, a lichen secondary metabolite. Toxicol In Vitro 25 462-468 Michalak A (2006) Phenolic compounds and their antioxidant activity in plants growing under heavy metal. Pol J Environ Stud 15 523-530... 

Investigations of Lichen Secondary Metabolites with Potential Anticancer Activity... 

This chapter focuses primarily on the anticancer properties of lichen secondary metabolites. We have reviewed various publications related to anticancer activity emphasizing results about specific lichen compounds. We have shown that various isolated lichen compounds often demonstrate significant inhibitory activity against various cancer cell lines at very low concentrations. Although lichens are a source for excellent anticancer active compounds, only a small number have been tested for their biological significance. This is om effort just another attempt to expand and deepen research in this area, especially on compounds that have shown promising results. 

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