Chamaejasmins, cytotoxic guaiane sesquiterpenes from the root of Stellera chamaejasme L.

Abstract Four new guaiane-type sesquiterpenes, chamaejasmins A–D (1–4), were isolated from the root of Stellera camaejasme L. collected in Nepal, together with two known terpenes, stelleraguaianone B (5) and 1α,7α,10αH-guaia-4,11-dien-3-one (6). The structures of 1–4 including their absolute configurations were determined by extensive 2D NMR analyses, mass spectroscopy, and TDDFT calculations of their 13C chemical shifts and ECD spectra. Chamaejasmin A (1) showed cytotoxicity against HeLa cells with an IC50 value of 6.3 μM.