*Article* **Sorbicillinoid Derivatives with the Radical Scavenging Activities from the Marine-Derived Fungus** *Acremonium chrysogenum* **C10**

**Chengbao Duan 1,2,†, Shiyuan Wang 1,2,†, Ruiyun Huo 1,2,†, Erwei Li <sup>3</sup> , Min Wang <sup>4</sup> , Jinwei Ren <sup>1</sup> , Yuanyuan Pan 1,\*, Ling Liu 1,2,\* and Gang Liu 1,2,\***


**Abstract:** Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus *Acremonium chrysogenum* C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (**1**–**3**), along with five known ones, trichotetronine (**4**), trichodimerol (**5**), demethyltrichodimerol (**6**), trichopyrone (**7**) and oxosorbicillinol (**8**), were isolated. The structures of new sorbicillinoids were elucidated by analysis of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS). The absolute configurations of compounds **1**–**3** were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound **3** exhibited a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the IC<sup>50</sup> value ranging from 11.53 ± 1.53 to 60.29 ± 6.28 µM in 24 h. Additionally, compounds **2** and **3** showed moderate activities against *Staphylococcus aureus* and *Cryptococcus neoformans*, with IC<sup>50</sup> values of 86.93 ± 1.72 and 69.06 ± 10.50 µM, respectively. The boundary of sorbicillinoid biosynthetic gene cluster in *A. chrysogenum* was confirmed by transcriptional analysis, and the biosynthetic pathway of compounds **1**–**8** was also proposed. In summary, our results indicated that *A. chrysogenum* is an important reservoir of sorbicillinoid derivatives, and compound **3** has the potential for new natural agents in DPPH radical scavenging.

**Keywords:** sorbicillinoids; *Acremonium chrysogenum*; structure elucidation; DPPH radical scavenging activity; antimicrobial compounds; marine natural products
