Isolation, total synthesis, and biological evaluation of dearomatized isoprenylated acylphloroglucinols from Hypericum przewalskii

New dearomatized isoprenylated acylphloroglucinols hyperprzewones A (1) and B (2) were isolated and characterized from the dried aerial parts of Hypericum przewalskii. The structures of these compounds were confirmed by extensive spectroscopic experiments. A facile synthetic route to 1 and 2 was developed via Friedel-Crafts acylation, alkylation, dearomatization, and oxidative [4 + 2] cyclization, giving a 17% overall yield. Moreover, the synthetic derivative 8 exhibited moderate inhibition on T-type calcium channels Ca_v3.2.