Study on chemical constituents of the lichen parmotrema tinctorum (NYL.) hale

Abstract

A phytochemical investigation was conducted on foliose lichen, Parmotrema tinctorum (Nyl.) Hale, collected in Lam Dong province, Vietnam. Color reactions for identification of lichen substances (+ K deep yellow, +C red, +KC red, +P pale yellow) suggested the presence of atranorin, lecanoric acid, quinones, depsides, and xanthones containing two free hydroxyl groups in meta-position. In fact, six compounds, including atranol (1), methyl haematomate (2), divaricatinic acid (3), methyl divaricatinate (4), atranorin (5) and lecanoric acid (6) were isolated in the acetone extract, in which isolates (3) and (4) were reported for the first time in such species. Their structures were elucidated by X-ray diffraction or spectroscopic data and compared with those in references.