New Hyperforin Derivatives from <i>Hypericum revolutum</i> V<scp>AHL</scp> with Growth‐Inhibitory Activity against a Human Colon Carcinoma Cell Line

Abstract

Abstract The crude petroleum‐ether extract of the root bark of Hypericum revolutum V AHL (Guttiferae) exhibited in vitro growth‐inhibitory activity against the Co‐115 human colon carcinoma cell line. Activity‐guided fractionation of this extract resulted in the isolation of two new hyperforin derivatives 1 and 2 . The structure of 1 (hyperevolutin A) was established by X‐ray analysis as the 4‐hydroxy‐8‐ exo ‐methyl‐5,7‐ exo ‐bis(3‐methylbut‐2‐enyl)‐1‐(2‐methyl‐1‐oxopropyl)‐8‐ endo ‐(4‐methylpent‐3‐enyl)bicyclo[3.3.1]non‐3‐ene‐2,9‐dione. The structure of the homologue 2 was deduced by comparison of its UV and 1 H‐ and 13 C‐NMR spectra with those of 1 .