Ionol Derivatives from Euphorbia tirucalli

A new ionol derivative, ( 2R, 6 S , 9 S ) -2-hydroxy -3-oxo-α-ionol (1), together with three known analogues, (6 S ,9 S )- 6-hydroxy- 3-oxo-α-ionol (2) , (6 R ,9 S )-3-oxo-α-ionol β -D- g lucopyranoside (3) and (6 R ,9 R )-3-oxo-α-ionol β -D-glucopyranoside (4), were isolated from the ethyl acetate extract of the aerial parts of Euphorbia tirucalli . Their structures were elucidated by means of extensive spectroscopic methods and comparison with the data reported in the literature. The absolute configuration of 1 was deduced by comparing experimental and calculated ECD spectra and 13C NMR data. The ionol d erivative s have been obtained for the first time from the genus Euphorbia.