*4.2. Sample Extraction*

From the sponge samples, a portion of 5 mg dry weight was solved in 500 μL of methanol. The sample was cut in small pieces and subsequently macerated in a shaker (140 rpm, 30 ◦C overnight). In a next step, the debris was pelleted by centrifugation in a table top centrifuge at full speed for 5 min. The supernatant was taken and the remaining material (pellet) was extracted one more time with

500 μL methanol. The supernatants were combined and evaporated under a flow of N2, before storage at −20 ◦C. The dry weight of the extract was determined and extraction efficiency was calculated. The crude extract was dissolved in dimethyl sulfoxide (DMSO, final concentration 1 mg/mL) for the antimicrobial assays and in methanol (1 mg/mL) for LC-HRMS measurement.
