Neuronal Modulators from the Coral-Associated Fungi Aspergillus candidus

Three new p-terphenyl derivatives, named 4 ''-O-methyl-prenylterphenyllin B (1) and phenylcandilide A and B (17 and 18), and three new indole-diterpene alkaloids, asperindoles E-G (22-24), were isolated together with eighteen known analogues from the fungi Aspergillus candidus associated with the South China Sea gorgonian Junceela fragillis. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic analysis, and DFT/NMR and TDDFT/ECD calculations. In a primary cultured cortical neuronal network, the compounds 6, 9, 14, 17, 18 and 24 modulated spontaneous Ca2+ oscillations and 4-aminopyridine hyperexcited neuronal activity. A preliminary structure-activity relationship was discussed.

Automated summary

Three new p-terphenyl derivatives and three new indole-diterpene alkaloids, along with known analogues, were isolated from the fungi associated with the gorgonian in the South China Sea. The structures and absolute configurations of the new compounds were elucidated through spectroscopic analysis and calculations. These compounds modulated neuronal activity and a preliminary structure-activity relationship was discussed.