UV photo-degradation of the secondary lichen substance parietin: A multi-spectroscopic analysis in astrobiology perspective
- Author:
- Lorenz C., Bianchi E., Alberini A., Poggiali G., Benesperi R., Papini A. & Brucato J.R.
- Year:
- 2024
- Journal:
- Life Sciences in Space Research
- Pages:
- 41: 191–201
- Url:
- https://doi.org/10.1016/j.lssr.2024.03.004
The cortical anthraquinone yellow-orange pigment parietin is a secondary lichen substance providing UVshielding properties that is produced by several lichen species. In our work, the secondary metabolite has
been extracted from air-dried thalli of Xanthoria parietina. The aims of this study were to characterize parietin
absorbance through UV–VIS spectrophotometry and with IR spectroscopy and to evaluate its photodegradability
under UV radiation through in situ reflectance IR spectroscopy to understand to what extent the substance may
have a photoprotective role. This allows us to relate parietin photo-degradability to the lichen UV tolerance in its
natural terrestrial habitat and in extreme environments relevant for astrobiology such as Mars. Extracted crystals
were UV irradiated for 5.59 h under N2 flux. After the UV irradiation, we assessed relevant degradations in the
1614, 1227, 1202, 1160 and 755 cm− 1 bands. However, in light of Xanthoria parietina survivability in extreme
conditions such as space- and Mars-simulated ones, we highlight parietin UV photo-resistance and its relevance
for astrobiology as photo-protective substance and possible bio-hint.
Keywords: Astrobiology ; Lichens ; Parietin ; UV radiation ; IR spectroscopy ; Biomarkers ; Life detection.
- Id:
- 36379
- Submitter:
- zpalice
- Post_time:
- Thursday, 28 March 2024 14:17