Hyperispirones A and B, spiro-bridged polycyclic polyprenylated acylphloroglucinols with anti-angiogenesis activity from Hypericum beanii

Two unprecedented spiro-bridged polycyclic polyprenylated acylphloroglucinols (PPAPs), one with a caged heptacyclo[18.3.1.0(1)(,20).0(2,17).0(3)(,)(15)0(6,)(15).0(8,13)]tetracosane core bearing a dual-bridged spiro central feature (1) and the other with an unusual 8-oxa-tetracyclo[7.4.2.0(1,9),0(3)(,7)]cetane ring system (2), were isolated and characterized from the aerial parts of Hypericum beanii. Their structures were elucidated by extensive analysis of HRESIMS, NMR, quantum-chemical calculations, and X-ray crystallographic data. A putative biosynthetic pathway for 1 was also proposed. Compounds 1 and 2 exhibited significant angiogenesis inhibitory effects against the tube formation of HUVECs.