*4.6. Cytotoxicity Assay*

The in vitro cytotoxicity assay was carried out as described earlier [8].

### *4.7. HPLC Fractionation and Bioassays in 96-Well Plates*

An Agilent 1260 Series HPLC–UV system equipped with a Waters, XBridge BEHC18, 2.1 mm 100 mm column (pore size 135 Å, particle size 3.5 μm, solvent A: H2O-acetonitrile (95/5), 5 mmol NH4Ac, 0.04 mL/L CH3COOH; solvent B: H2O-acetonitrile (5/95), 5 mmol NH4Ac, 0.04 mL/L CH3COOH; gradient system: 10% B increasing to 100% B in 30 min; flow rate 0.3 mL/min; 40 ◦C; UV-detection at 210–450 nm) was used for the chromatographic fractionation of crude extracts. The same HPLC gradient was used as for the high-resolution electrospray ionization mass spectrometry (HRESIMS) instrument. The flow-through was collected in 30 s intervals into a 96-well microtiter plate. Afterwards, the plates were dried by a constant nitrogen-flush for 40 min, inoculated with 150 mL indicator bacteria per well and incubated as described [17]. After 24 h the plates were evaluated and documented employing a custom-made mirror stand and a CANON EOS 60D digital camera.
