Kiiacylphnols A-H, eight undescribed polycyclic polyprenylated acylphloroglucinols with anticancer activities from Hypericum przewalskii Maxim

Abstract

Kiiacylphnols A-H, eight previously undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs), along with two known congeners (hyperforcinol F and oxepahyperforin), were obtained from Hypericum przewalskii Maxim. The structures of these metabolites were confirmed by spectroscopic analyses, quantum-chemical ¹H and ¹³C NMR calculations with DP4+ analyses, electronic circular dichroism (ECD) comparisons and calculations. Kiiacylphnols A and B were the first [3.3.1]-type PPAPs with an unusual octahydrooxireno[2,3-i]chromene scaffold bearing a rare 6/6/6/3 ring system. More significantly, kiiacylphnol A and oxepahyperforin displayed cytotoxicity against acute myeloid leukemia and diffuse large B-cell lymphoma cell lines by inducing cell apoptosis.

Keywords: Cytotoxic activity; Hypericaceae; Hypericum przewalskii Maxim.; Polycyclic polyprenylated acylphloroglucinols.