Bioactive Indole Diketopiperazine Alkaloids from the Marine Endophytic Fungus sp. YJ191021.

Six new prenylated indole diketopiperazine alkaloids, asperthrins A-F (-), along with eight known analogues (-), were isolated from the marine-derived endophytic fungus sp. YJ191021. Their planar structures and absolute configurations were elucidated by HR-ESI-MS, 1D/2D NMR data, and time-dependent density functional theory (TDDFT)/ECD calculation. The isolated compounds were assayed for their inhibition against three agricultural pathogenic fungi, four fish pathogenic bacteria, and two agricultural pathogenic bacteria. Compound exhibited moderate antifungal and antibacterial activities against pv. , and with minimal inhibitory concentration (MIC) values of 8, 12.5, and 25 μg/mL, respectively. Furthermore, displayed notable anti-inflammatory activity with IC value of 1.46 ± 0.21 μM in induced human monocyte cell line (THP-1).