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Antioxidant and cytoprotective potentials of Parmeliaceae lichens and identification of active compounds

3.4.Phytochemical analysis Identification of the different components was done
based on the Rf values (ratio between the distance run by
In view of the results of ORAC and cytoprotective the compound and by the eluent) and their comparison
assays, we carried out a phytochemical analysis for the with those values present in scientific bibliography (28).
extracts of the three species under study (Cetrelia Table 4 collects the data obtained through TLC analyses
braunsiana, Parmotrema saccatilobum and Usnea with the compounds identified for each lichen specie.
ghattensis) with the purpose to correlate the antioxidant
potential with their chemical composition.

Table 4. Chemical composition determined through TLC analyses for the methanol extracts of Cetrelia
braunsiana (Cb), Parmotrema saccatilobum (Ps) and Usnea ghattensis (Ug).

Compound Rf Cb Ps Ug

Usnic acid 0.71 - - +

Stictic acid 0.18 - - +

Constictic acid 0.20 - - +

Alectoronic acid 0.17 + - -

Atranorin 0.79 + + -

Protocetraric acid 0.50 - + -

Salazinic acid 0.40 - - -

Evernic acid 0.43 - - -

On the other hand, we performed a reverse phase (17.40 ± 0.23 min) in Usnea ghattensis. Results of
HPLC analysis of the methanol extracts in order to deepen retention times are expressed as mean value of three
on phytochemical characterization, since it is a more different analyses, and chromatograms obtained for the
sensitive and specific method. Chromatograms obtained three species are collected in Figure 1.
for the three species under study were evaluated by
comparing the retention times (tR) of their main peaks to
the chromatograms of the standards, analyzed under the
same experimental conditions. For that purpose,
Neofuscelia glabrans (containing alectoronic acid),
Neofuscelia parviloba (with usnic acid) and
X anthoparmelia exemplaris (with protocetraric acid) were
used as references. Through the HPLC method, we
identified the following compounds: alectoronic acid (9.21
± 0.20 min) in Cetrelia braunsiana, protocetraric acid (4.90
± 0.11 min) in Parmotrema saccatilobum, and usnic acid

@Real Academia Nacional de Farmacia. Spain 173