ABSTRACT

Alantolactone/isoalantolactone, a mixture of isomeric sesquiterpene compounds, was isolated from the roots of Inula helenium L. subsp. turcoracemosa Grierson and its amount was quantified by RPHPLC. The structure of alan-tolactone/isoalantolactone was elucidated by using HPLC and 1NMR data. Alantolactone/isoalantolactone was fo-und in serious amount in the roots of the plant as 1.6338 ± 0.0198 % (w/w). The roots of Inula helenium subsp. tur-coracemosa growing in Turkey were found rich in this isomeric pair known to be strong antiproliferative and anti-microbial agent.