Patumantanes A–D, seco-Polycyclic Polyprenylated Acylphloroglucinols with Diverse Carbon Skeletons from Hypericum patulum

Abstract

Patumantanes A−D (1−4), four new seco-polycyclic polyprenylated acylphloroglucinols (PPAPs) were isolated from Hypericum patulum. Patumantane A (1) was an unprecedented 1,2-seco-homoadamantane-type PPAP bearing a new 3,7dioxatetracyclo[7.7.0.0 1,6 .1 11,15 ]heptadecane architecture based on a 6/7/5/6 ring system. Patumantane B (2) was a unique 1,9-secoadamantane-type PPAP with a tricyclo[4.4.4.0.0 2,12 ]tridecane core formed by a 6/6/6 carbon skeleton, and the further breakage between C-5 and C-9 decorated patumantane C (3) with the 9-nor-adamantane skeleton. More importantly, compounds 2 and 3 exhibited moderate immunosuppressive activity on Con A-induced T-lymphocyte proliferation in vitro, with IC 50 values of 5.6 ± 1.2 and 11.2 ± 1.2 μM, respectively.