Lichen secondary metabolites in Umbilicaria antarctica evaluated by acetone rinsing ( Short Communication )

Abstract

Study of the extracts from an Antarctic lichen Umbilicaria antarctica was done using a spectrophotometric approach. Secondary compounds were extracted by acetone rinsing from dried thalli of U. antarctica. The extracts were dried out, and diluted in ethanol. Then, spectral absorbance of the extracts were measured within the wavelength of 190-700 nm. The spectra of the secondary compounds obtained by acetone rinsing (EAR – re-diluted (ethanol) extract gained during acetone rinsing) were compared with those from untreated thalli (control) and ethanol extract from the thalli of U. antarctica that passed acetone rinsing (ART). Spectral absorbance curves of the extracts gained by acetone rinsing were attributed to different prevailing secondary metabolites: usnic acid, lecanoric acid (U. antarctica). Spectral absorption curves of control thalli exbibited similar shape as ART spectral curves, however, the absorbance in the range of 230-310 nm reached higher values in control than in ART. Spectral absorbance curves from ART showed that a part of secondary metabolites still remained in the thalli. Photosynthetic pigments (carotenoids and chlorophylls) remained uneffected by acetone rinsing.