Degradation of alectorialic acid in the lichen genusUsnea

Chemical Composition and Antimicrobial Activity of Two Sri Lankan Lichens, Parmotrema rampoddense, and Parmotrema tinctorum against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

“…Lichen acids, atranorin, and lecanoric acid were detected in the TLC profile of P. tinctorum and the GC-MS analysis confirmed the presence of atraric acid, orcinol, and O-orsellinaldehyde among the major constituents. Previous studies have also detected O-orsellinaldehyde and orcinol as bioactive derivatives obtained from lecanoric acid [38][39][40]. Similar antimicrobial activities were reported by Gomes et al for the lecanoric acid isolated from the lichen, P. tinctorum [41].…”

“…Furthermore, the hexane extract of the lichen indicated significant quantities of n-alkanes and methyl esters of fatty acids similar to Xanthoria parietina species [37]. It is a known fact that relatively unstable lichen substances are degraded in the lichen itself or in vitro in their extracts at room temperature and Zakeri et al [38] have shown that alectorialic acid is a relatively unstable substance which can be degraded to other compounds at room temperature. erefore, degradation products have been reported in the GC-MS analysis.…”

Usnea viktoriana(Ascomycota,Parmeliaceae), a new European taxon of theUsnea barbata-dasopogagroup, with a key to the shrubby-subpendulous sorediateUsneaspecies in Europe

“…When we analyzed these three specimens again with TLC, no trace of the stictic acid group was found but instead alectorialic acid and its degradation products (see Zakeri et al 2017). Until now we have refrained from describing this morphotype with alectorialic acid as a distinct taxon because of some seemingly intermediate forms with U. dasopoga (Ach.)…”

“…Its chemistry, including the degradation products of alectorialic acid detectable by thin-layer chromatography (TLC) and high-performance liquid chromatography-mass spectrometry (HPLC-MS), was recently studied in detail by Zakeri et al . (2017). The same morpho- and chemotype was keyed out to probably represent an undescribed species in Clerc (2013) as “ U. dasopoga s. l.”.…”

“…Its frequent occurrence in previously polluted areas recently colonized by Usnea species in Germany was mentioned by Otte & Landeck (2012) under "U. diplotypus Alectorialsäure-Chemotyp". Its chemistry, including the degradation products of alectorialic acid detectable by thin-layer chromatography (TLC) and highperformance liquid chromatography-mass spectrometry (HPLC-MS), was recently studied in detail by Zakeri et al (2017). The same morpho-and chemotype was keyed out to probably represent an undescribed species in Clerc (2013) as "U. dasopoga s. l.".…”