Studies on Chilean lichens part XXIX. New contribution in Umbilicaria decussata

Most species in the genus Umbilicaria accumulate high concentration of the tridepside gyrophoric acid, often accompanied by a smaller amount of its pr obable depside precursor lecanoric acid. Previous research on Umbilicaria d ecussata confirm the above statement However, chemical analysis of a sample of U.decussata, collected in the San Francisco river valley (Region Metrop olitana, Chile) reveals lecanoric acid as the only specific metabolite, and in very high concentration, besides ergosterol and its endoperoxide and th e triterpenes 7-beta-acetoxy-22-hidroxyhopane and leucotylin.