Elecanacin, a novel new naphthoquinone from the bulb of Eleutherine americana

Abstract

A novel new naphthoquinone called elecanacin (9) and a new naphthalene called isoeleutherol (10) were isolated from the bulb of Eleutherine americana MERR. et HEYNE (Iridaceae), together with two known naphthoquinones (2 and 3). The structures were determined by spectroscopic methods including the 2D-NMR techniques. Eleutherin (2) showed interesting inhibitory activity against human topoisomerase II, and isoeleutherin (3) and isoeleutherol (10) showed inhibitory activity against HIV.