*4.6. Dereplication of Fractions*

One mg of each fraction A to E were resuspended in 100 μL 80% aqueous methanol, centrifuged at 13,000 rpm for 5 min, and the supernatants were transferred to UHPLC injection vials. UHPLC-HR-MS/MS analysis of the fractions was performed using a Waters Acquity I-class UPLC system interfaced with a PDA Detector and a VION IMS-qTOF (Milford, MA, USA) using electrospray ionization (ESI) in positive mode. The VION IMS- qTOF was operated with a capillary voltage of 0.80 kV, desolvation gas flow (N2) of 800 L/h, desolvation temperature of 450 ◦C, cone gas flow (N2) of 50 L/h and an ion source temperature of 120 ◦C. Data were acquired between *m*/*z* 50 and 2000 with a scan time of 0.2 s. Fragment data were acquired by ramping the energy of the collision cell from 15 to 45 V, and high and low energy data were acquired in the same run. Leucine-enkephalin was used

for internal calibration and the system was tuned to a resolution of 45,000 (FWHM). The system was controlled, and data were processed using UNIFI 1.9.4 (Waters). Chromatographic separation was achieved by injecting 3 μL of the dissolved fractions on a BEH C18 1.7 μm (2.1 × 100 mm) column (Waters) operated at 40 ◦C. The fractions were eluted with a gradient of 10% to 100% acetonitrile in water over 10 min (both containing 0.1% formic acid), followed by maintaining 100% acetonitrile until 13.5 min.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1660-3397/18/3/166/s1, Figure S1: Top: Base peak intensity chromatogram from the UHPLC-HR-MS/MS analysis of fraction C using positive electrospray. Bottom: Ion chromatogram of m/z 184. 0740 from fraction C indicating the presence of phosphocholines, Figure S2: Top: Ion chromatogram of m/z 496.3396 from fraction C showing the presence of LysoPC. Bottom: Base peak intensity chromatogram from the UHPLC-HR-MS/MS analysis of fraction C using positive electrospray, Figure S3: Top: Low energy mass spectrum of 1-Palmiotyl-sn-glycero-3-phosphocholine from fraction C. Bottom: High energy mass spectrum of 1-Palmiotyl-sn-glycero-3-phosphocholine showing fragments and mass deviations corresponding with the commercial standard, Figure S4: Top: Low energy mass spectrum of pheophorbide A from fraction D. Bottom: High energy mass spectrum of pheophorbide A showing fragments and mass deviations corresponding with the theoretical fragmentation of the database hit, Figure S5: Top: Low energy mass spectrum of hydroxypheophorbide A from fraction D. Bottom: High energy mass spectrum of hydroxypheophorbide A showing fragments and mass deviations corresponding with the theoretical fragmentation of the database hit, Table S1: The most abundant lysophosphatidylcholines in fraction C. The type indicates number of carbons and double bonds in the fatty acid moiety of the respective LysoPCs, and the retention times are given in minutes.

**Author Contributions:** C.L. and E.H.H. conceived and designed the experiments; C.L., K.H., G.R., and E.H.H. performed the experiments; C.L., K.H., G.R., and E.H.H. analyzed the data. All authors (C.L., K.H., G.R., J.H.A., A.I. and E.H.H.) co-wrote the paper. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the "Antitumor Drugs and Vaccines from the Sea (ADViSE)" project (PG/2018/0494374).

**Acknowledgments:** We thank Massimo Perna and Mariano Amoroso for their technical support.

**Conflicts of Interest:** The authors declare no conflict of interest.
