**4. Conclusions**

Three new bianthraquinones, alterporriol Z1–Z3 (1–3), along with three known compounds (4–6) of the same structural class, were isolated from the culture broth of a marine-derived *Stemphylium* sp. fungus. Based upon the results of combined spectroscopic analyses and ECD measurements, the structures of new compounds were determined to be the 6-6- - (1 and 2) and 1-5- - (3) C-C connected *pseudo*-dimeric anthraquinones, respectively. The absolute configuration of the chiral axis of 4 was also assigned similarly. In addition, three new meroterpenoids, tricycloalterfurenes E–G (7–9), isolated from the same fungal culture broth, were structurally elucidated by combined spectroscopic methods. The relative and absolute configurations of these meroterpenoids were determined by modified Mosher's, PGME, and computational methods. Although none of these compounds were active against cytotoxic and antibacterial assays, the bianthraquinones (except 3) exhibited significantly inhibited nitric oxide (NO) production and suppressed the expression of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1660-3397/18/9/436/s1. Figures S1–S45: HRFABMS, 1D and 2D NMR spectra of 1–3 and 7–9, Figures S46–S49: 1H NMR spectrum of (*S*), (*R*)-MTPA Ester of 7–8, Figures S50-S53: 1H NMR spectrum of (*S*), (*R*)-PGME Amide of 7–8, Figure S54: The results of DP4 probability analysis of 1, Figure S55: The viability of RAW 264.7 cells was measured using the MTT assay, Table S1: Experimental (Exp.) and calculated (Cal.) chemical shift values of enantiomers A and B on aliphatic ring part of 1, Table S2: 1H NMR Data of 1 in THF-*d8*.

**Author Contributions:** J.-Y.H. and S.C.P. carried out isolation and structural elucidation; W.S.B. and S.K.L. performed the anti-inflammatory activity bioassay; K.-B.O. performed antimicrobial and enzyme inhibition bioassays; J.S. and D.-C.O. reviewed and evaluated all data; J.S. and K.-B.O. supervised the research work and prepared the paper. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the National Research Foundation (NRF, grant no. 2018R1A4A1021703) funded by the Ministry of Science, ICT, & Future Planning, Korea.

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