Sesquiterpenoids from Hedyosmum orientale

Five new guaiane-type sesquiterpenoids, hedyosumins A-E (1-5), together with five known ones (6-10), were isolated from the aerial parts of Hedyosmum orientale. Two known sesquiterpenoids, 10 alpha-hydroxy-1,5 alpha H-guaia-3,7(11)-dien-8 alpha, 12-olide and 9 alpha-hydroxyasterolide, were obtained as natural products for the first time. Their structures were elucidated on the basis of spectroscopic methods. 9 alpha-Hydroxyasterolide (7) showed moderate activities against A-549 and HL-60 tumor cell lines with the IC50 values of 3.1 and 8.8 mu M, respectively.