Halogenated anthraquinones from the rare southern Illinois lichen Lasallia Papulosa

Abstract

Four anthraquinones were isolated from the foliose lichen, Lasallia papulosa (Ach.) Llano. Two of the anthraquinones are known compounds, previously isolated from Lasallia papulosa, while the other two were reported previously as secondary metabolites from laboratory-cultured Nephroma laevigatum, and are isolated here for the first time from lichens in their natural habitat. All compounds were characterized by UV spectrophotometry, mass spectrometry, 1H NMR and 13C NMR. The products were identified as 7-chloroemodin, valsarin (7-chloro-5-hydroxyemodin), 5-chloro-1-O-methylemodin and 5-chloro-1-O-methyl-ω-hydroxyemodin.

Climate‐specific biosynthetic gene clusters in populations of a lichen‐forming fungus

“…pustulata , it has been reported from U . papulosa ‐ a congeneric species with North American distribution preferentially at high altitudes (Bohman, 1969; Cohen, 2002). The fixation of deleterious mutations specific to cold‐temperate populations likely resulting from selective sweeps shows that genetic hitchhiking is another powerful force driving the evolution of the biosynthetic landscape in fungi.…”

“…The loss of function of this cluster could thus provide a selective advantage to cold-temperate populations which occur at higher altitude and might experience higher levels of UV radiation. Although emodin has not been reported from U. pustulata, it has been reported from U. papulosa -a congeneric species with North American distribution preferentially at high altitudes (Boh man, 1969;Cohen, 2002). The fixation of deleterious mutations specific to cold-temperate populations likely resulting from selective sweeps shows that genetic hitchhiking is another powerful force driving the evolution of the biosynthetic landscape in fungi.…”