**4. Conclusions**

Chemical investigation of a marine-derived fungus *Aspergillus versicolor* DY180635 led to the isolation and identification of four new IDPKs, aspamides A–E (**1–4**) and two new DPKs, aspamides F–G (**5–6**), along with 11 known diketopiperazines and intermediates. Further chiral high-performance liquid chromatography resolution gave enantiomers (+)- and (−)-**4**, respectively. The structures and absolute configurations of compounds **1–6** were determined by the comprehensive analyses of NMR, HRESIMS, and ECD calculation. Compounds **1–17** were selected for the virtual screening on the 3CL hydrolase (Mpro) of SARS-CoV-2, and compounds **1–2**, **5**, **6**, **8** and **17** possessed top docking scores and thus may be helpful in fighting COVID-19 after further studies.

**Supplementary Materials:** The following are available online at: http://www.mdpi.com/1660-3397/18/7/338/s1, Figures S1–S46: 1H, 13C, HSQC, HMBC, ROESY, UV, ECD, and HRESIMS spectra of the new compounds **1**–**6**, Tables S1–S6: Computational data of **1** and **4**.

**Author Contributions:** Y.D. performed the isolation, purification and identification of all compounds. X.Z. tested the anti-inflammatory activities. L.H. and M.Z. supervised the laboratory work. Q.H. edited the manuscript. F.A. supervised the laboratory work, designed the experiments and edited the manuscript. All authors have read and agree to the published version of the manuscript.

**Funding:** This work was funded by the National Key R&D Program of China (2018YFC1706200, 2019YFC0312504), and the National Natural Science Foundation of China (41876189, 81703388). This work was also supported by State Key Laboratory of Bioreactor Engineering. Authors thank Prof. Lixin Zhang (State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology) for assistance in the virtual screening on the Mpro of SARS-CoV-2.

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