Current Results on Biological Activities of Lichen ... - Lichens and Me

168 K. Molnár and E. Farkas · Biological Activities of Lichen Substances
Conclusions
More than 1000 secondary products have been
identified to date in lichens, and new compounds
will certainly be found from poorly studied or
newly discovered lichens, especially from the
under-collected tropics. Here we have shown that
lichen secondary substances exhibit a huge array
of remarkable biological activities, and many of
them have important ecological roles. Some of the
activities already mentioned (e.g., photoprotection,
reaction to pollution) should be thoroughly
studied. Furthermore, the properties of lichen
substances make them possible pharmaceuticals.
At the same time, we have to be aware that lichens
are slow-growing ecosystems, and exploitation
of their secondary products could threaten
their survival. However, improved culture methods
and varied growing conditions can positively
influence secondary metabolite production in
aposymbiotically grown mycobionts (Stocker-
Wörgötter, 2008) and in cultured lichens (Behera
et al., 2009), without having to harvest and put at
risk the extinction of natural communities.
Acknowledgements
Our sincere thanks are due to Chicita F. Culberson
for her invaluable help with the literature
and useful comments on the manuscript. The authors
are grateful to Molly McMullen for revision
of the text. We would like to thank Lucyna Śliwa,
Suzanne Joneson, and Ester Gaya for their helpful
comments on an earlier version of the manuscript.
K. M. is also thankful to François Lutzoni
for his support during the completion of her thesis
on Hypogymnia physodes. Special thanks are
due to Duke University Libraries for providing
the literature. The preparation of this paper was
supported also by the Hungarian Scientific Research
Fund (OTKA T047160).
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