Yezo’otogirins D–H, Acylphloroglucinols and Meroterpenes from Hypericum yezoense

Investigation of the methanolic extract from the aerial parts of Hypericum yezoense resulted in the isolation of three new acylphloroglucinols, yezo’otogirins D–F (1–3), and two new meroterpenes, yezo’otogirins G (4) and H (5). The structures of 1–5 were assigned on the basis of spectroscopic data. Yezo’otogirin D (1) is an acylphloroglucinol with a monoterpene moiety linked through an ether bond, while yezo’otogirins E (2) and F (3) are polyprenylated acylphloroglucinols possessing a tricyclic core. Yezo’otogirins G (4) and H (5) are linear meroterpenes with an enolized β-diketone moiety. Yezo’otogirin E (2) exhibited antimicrobial activity against Escherichia coli and Staphylococcus aureus.