8.

Chemical Constituents of the Epiphytic and Lithophilic Lichens of the Genus Collema

Marina Temina, Dmitri O. Levitsky and Valery M. Dembitsky

Biodiversity and Biotechnology Center of Cryptogamic Plants and Fungi,
Institute of Evolution, Haifa University, Haifa 31905, Israel

CNRS UMR 6204, Biotechnologie, Biocatalyse et Biorégulation, Faculté des Sciences et des Techniques, Université de Nantes, 44037 Nantes Cedex 03, France

Institute for Drug Research, P.O. Box 12065, Hebrew University, Jerusalem, 91120, Israel

Abstract: Biodiversity of secondary lichen metabolites by the epiphytic and lithophilic lichens of the genus Collema is reported. The most abundant fatty acids were a-linolenic acid (18:3n-3), oleic acid (18:1n-9), and palmitic acid (16:0), but a great variation of the ester composition from one to another was found. A comparison of neutral lipids, glycolipids, polar lipids and fatty acid composition of four species was done. DGTS, DGTA, PC, and PI were found as major components among polar lipids. Chemical constituents were characterized by GC-MS, HPLC, HR-TLC, and other chemical methods. Biological activity of isolated compounds from Collema species is also discusses. Several indole alkaloids and other nitrogen-containing metabolites have been isolated from the genus Collema: C. cristatum, C. callopismum, C. fuscovirens and C. flaccidum

Keywords: Collema; fatty acids; polar lipids; nitrogen-containing metabolites, indole alkaloids