A Drimane Meroterpenoid Borate as a Synchronous Ca + Oscillation Inhibitor from the Coral-Associated Fungus Alternaria sp. ZH-15.

Territrem F ( 1 ), a drimane meroterpenoid bearing a unique borate ring system, was isolated together with its diol precursor territrem B ( 2 ) from the fungus Alternaria sp. ZH-15 associated with the soft coral Lobophytum crassum collected in the South China Sea. The structure of the new compound was elucidated by spectroscopic analysis and an X-ray single-crystal diffraction study, representing a new type of boron-containing natural product. Both compounds significantly inhibited spontaneous synchronous Ca ²⁺ oscillations (SCOs) and epileptic discharges induced by 4-aminopyridine, showing the potential for antiepileptic drug research. The 5,9-boronic ester derivative of 2 did not change its SCO inhibitory activity.