Beshanzuamide A, an unprecedented prenylated indole alkaloid produced by Aspergillus sp. Y-2 from the critically endangered conifer Abies beshanzuensis .

A structurally unprecedented prenylated indole alkaloid, beshanzuamide A (1), together with five known analogues (2-6) were isolated and identified from the endophytic fungus derived from the needles of the critically endangered conifer Abies beshanzuensis . The new structure was determined by extensive spectroscopic methods and quantum chemical calculations of NMR and electronic circular dichroism (ECD) data. Compound 1 features a unique N , O -spiroketal/δ-lactone motif connected to a pyranoindole-derived bicyclo[2.2.2]diazaoctane ring. A plausible biogenetic pathway for the assembly of 1 was proposed.