Isoprenylated Naphthoquinone Dimers Firmianones A, B, and C from <i>Firmiana </i><i>p</i><i>latanifolia</i>

Abstract

Three new compounds designated as firmianones A, B, and C (1-3), along with 13 known compounds, were isolated from the roots of Firmiana platanifolia. Their structures were elucidated by interpretation of HRESIMS, 1H-1H COSY, HMQC, HMBC, and NOESY. The absolute configurations of firmianones A and B with a rare hexacyclic skeleton were determined by CD exciton-coupling experiments. Firmianones A and B exhibited moderate cytotoxicity to the P388 cancer cell line.