*3.2. LC-MS*/*MS Analysis*

The contents of cyanobacterial extracts, fractions and isolated compounds, were analyzed with the application of an Agilent 1200 (Agilent Technologies, Waldboronn, Germany) HPLC system coupled with a hybrid triple quadrupole/linear ion trap mass spectrometer (QTRAP5500, Applied Biosystems, Sciex, Concorde, ON, Canada). For peptide separation a Zorbax Eclipse XDB-C18 column (4.6 × 150 mm; 5 μm) (Agilent Technologies, Santa Clara, CA, USA) was used. The mobile phase was composed of a mixture of 5% acetonitrile in MilliQ water (A2) and acetonitrile (B2), both with the addition of 0.1% formic acid. A gradient elution at 0.6 mL min−<sup>1</sup> was applied. The system operated in positive mode with a turbo ion spray (550 ◦C; 5.5 kV). The non-targeted information-dependent acquisition (IDA) mode was applied to screen the content of the samples. Fragmentation spectra of ions within the *m*/*z* range 400–1000, and signal intensity above 500,000 cps were collected, at a collision energy of 60 ± 20 eV. The structures of aeruginosamides were additionally characterized using targeted enhanced product ion (EPI) mode.
