Some constituents of the lichen Ramalina siliquosa

Abstract

Extraction of Ramalina siliquosa gave, in addition to (+)-usnic acid and D-(+)-arabitol, hypoprotocetraric acid, a depsidone previously known only in the laboratory. A trace of a mixture tentatively identified as atranorin and chloroatranorin was also isolated as well as a crude fraction resembling tetrahydroxy fatty acid mixtures known from other lichens. A microchemical survey of the principal phenolic constituents of 57 herbarium specimens revealed six distinct chemical races in the collective species R. siliquosa. © 1965.