Sorbicillalanines A and B, Two [6,5,6] Hybrid-Sorbicillinoid Alkaloids from Deep-Sea-Derived Penicillium sp. Co-Cultured with Sponge-Derived Setosphaeria sp.

Sorbicillalanines A (1) and B (2), two unusual hybrid-sorbicillinoid alkaloids, were isolated from Penicillium sp. co-cultured with Setosphaeria sp. Their structures containing absolute configurations were determined by detailed spectroscopic analysis and ECD and NMR calculations. Structurally, 1 and 2 are the first sorbicillinoids characterized by an unprecedented [6,5,6]-fused ring skeleton with a piperidin-2-one ring. A plausible biosynthetic pathway for 1 and 2 was put forward. 1 displayed significant anti-inflammatory activity in LPS-induced RAW 264.7 macrophages.