In Usnea aurantiaco-atra, growing in the Antarctica, a monthly variation in the usnic acid content, in individual thalli, was studied by means of scanning densitometry (HPTLC). The higher accumulation rates were quantified from January to May; there was a significant decrease in the concentrations from June to December, during the three years of study. In spite of the thalli were taken from a same location, variations could be observed in the usnic acid concentration in the individuals from within each monthly sample.
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Data Set Citation
Wanda Quilhot et al
Lichen secondary products and their importance in environmental studies
Dataset Release Date:
Dataset Release Place:
Sao Paulo, Brazil
Lichenology in Latin America: history, current knowledge and applications
Mats of Usnea aurantiaco-atra, growing in an open space, were collected monthly -when possible- in the area of Baliza Poisson, Arturo Prat Base, and Greenwich Island from February 1987 to December 1989. The lichenic material was dried at room temperature and was packed until it was taken to the laboratory. Fifteen erect ... sterile thalli were chosen randomly from two mats per month. The dry weight of each thallus was estimated in an oven at 50 deg. C; then they were macerated in acetone successively for 72 h and 24 h, at room temperature. The extracts were filtered and combined. The quantification of usnic acid was performed though scanning densitometry (HPTLC).