*3.3. Inhibitory Effects on Hepatitis C Virus (HCV) Infectivity*

The anti-HCV assay was performed as mentioned in [5]. In brief, Huh7.5 cells stably expressing Firefly luciferase (Huh7.5 Fluc) were cultured in Dulbecco's modified minimum essential medium (DMEM, Gibco, Thermo Fisher Scientific, Schwerte, Germany) and maintained in a 37 ◦C environment with 5% CO2 supply. Samples were added to the cells, and then the cells were infected with Jc1-derived *Renilla* reporter viruses. Compounds and the positive control (Epigallocatechin gallate, EGCG) were tested at a concentration of 10 μg/mL. *Renilla* and *Firefly luciferase* activities from the infected cells were measured on a Berthold Technologies Centro XS3 Microplate Luminometer (Bad Wildbad, Germany) as indicators of viral genome replication and cell viability, respectively.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/1660-339 7/19/2/81/s1. Figure S1. The HRMS spectra of compounds **1**–**4**; Figures S2–S5. Mirror-match of compounds **1**–**4** with valinomycin from the MASST GNPS database; Figures S6–S10. MS<sup>2</sup> spectra of the compounds **1**–**4**; Tables S1–S4. 1H-NMR from [6]; Figures S11–S15. 1H-NMR of compounds **1**–**4** in CDCl3; Figure S16. 1D 13C-NMR spectrum of streptodepsipeptide SV21 (**4**) in CDCl3; Figure S17. 1D 1H-NMR spectrum of streptodepsipeptide SV21 (**4**) in CDCl3; Figure S18. Full HSQC spectrum of streptodepsipeptide SV21 (**4**).

**Author Contributions:** J.T.W., M.Y.K., M.K., E.S., K.I.M., J.W., and P.J.S. conceived and designed the experiments; J.T.W., M.Y.K., D.F.P., M.K., and K.I.M., performed the experiments; J.T.W., M.Y.K., M.K., D.F.P., K.I.M., and P.J.S. analyzed the data; J.T.W., M.Y.K., and P.J.S. wrote the paper; J.W., T.M., M.Y.P., and D.F.P. reviewed and edited the paper. All authors have read and agreed to the published version of the manuscript.

**Funding:** JTW acknowledges funding by DAAD special program Germany-Indonesia Anti-infective Cooperation. P.J.S. acknowledges funding by the Federal Ministry of Education and Research (BMBF) for the GINAICO project, grant 16GW0106 and DFG funding INST 1841147.1FUGG for the high-resolution mass spectrometer Waters Synapt G2-Si.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding authors.

**Acknowledgments:** We are grateful to DAAD for the PhD scholarship special program Biodiversity and Health (2016 for J.T.W., 2017 for D.F.P.), to the University of Oldenburg for a STIBET short term scholarship, and to Indonesian Institute of Sciences (LIPI) for granting a study leave (J.T.W.) and for the support in taking samples. Research was carried out under the GINAICO Cooperation Agreement from July 2015 and respective MTA and MOU between University of Oldenburg and RCO LIPI, Jakarta. P.J.S. acknowledges research permit by Ristekdikti Jakarta, Indonesia, number 1493/FRP/E5/Dil.K!/VII/2017. We also like to thank the editor and two reviewers for their valuable comments which helped to improve the manuscript.

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