Sorbicillinoid Derivatives with the Radical Scavenging Activities from the Marine-Derived Fungus C10.

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 C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A-C (-), along with five known ones, trichotetronine (), trichodimerol (), demethyltrichodimerol (), trichopyrone () and oxosorbicillinol (), 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 - were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound exhibited a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the IC value ranging from 11.53 ± 1.53 to 60.29 ± 6.28 μM in 24 h. Additionally, compounds and showed moderate activities against and , with IC values of 86.93 ± 1.72 and 69.06 ± 10.50 μM, respectively. The boundary of sorbicillinoid biosynthetic gene cluster in was confirmed by transcriptional analysis, and the biosynthetic pathway of compounds - was also proposed. In summary, our results indicated that is an important reservoir of sorbicillinoid derivatives, and compound has the potential for new natural agents in DPPH radical scavenging.