The effect of thallus age and drying procedure on extractable lichen substances

Abstract

Cladonia rangiferina (L.)Wigg., Cladonia mitis Sandst., and Umbilicaria muhlenbergii (Ach.) Tuck, were extracted with acetone while damp and after three different drying procedures. The extracts were chromatographed and scanned spectrophotometrically. Some of the C. rangiferina compounds were not extractable from damp material. All of the lichen substances studied here decreased significantly in thalli which were dried in an oven at 80 °C, some to the point of imperceptibility. There was no qualitative difference between the complement of compounds found in lichen material dried at 22 °C and at 40 °C. We recommend that drying be carried out at a temperature not exceeding 40 °C. Chemical variability among thallus regions of different ages was studied in Cladonia rangiferina, C. mitis, Umbilicaria muhlenbergii, and Lasallia papulosa (Ach.) Llano. Fumarprotocetraric acid, atranorin, and usnic acid were present in significantly higher amounts in younger tissue than in older. Protocetraric acid in C. rangiferina was detectable only in the older portions and would have been overlooked if young branches had been analyzed exclusively. In neither of the two umbilicate lichens was there any significant difference in the concentration of gyrophoric acid between younger and older thallus parts. Chemical variability among different-aged thallus parts was thus greater in the fruticose species than in the umbilicates examined here.