Degradation of alectorialic acid in the lichen genus Usnea

[...]we have identified an alternative set of degradation products derived from alectorialic acid following our recent studies using thin-layer chromatography (TLC) and high performance liquid chromatography-mass spectrometry (HPLC-MS). Ionization was achieved by atmospheric pressure chemical ionization-electrospray ionization multimode (APCI/ESI) in the negative and positive mode. A second HPLC scan of the same acetone extract of Usnea diplotypus, which had been stored for 24 h at room temperature, revealed that the concentration of alectorialic acid had decreased while the concentration of haematommic acid and 5,7-dihydroxy-6-methylphalide had increased; relative concentrations of alectorialin and usnic acid remained the same (Fig. 1B).