<p>A new phorbol-type diterpene ester, 4,20-dideoxy-4<i>α</i>-phorbol-12<i>β</i>-acetate-13<i>α</i>-isobutyrate, in addition to 11 known compounds were isolated from the latex and roots of <i>Euphorbia clementei</i> Boiss. Structure elucidation was performed by comprehensive 1D and 2D NMR analyses (<sup>1</sup>H and <sup>13</sup>C NMR, COSY, ROESY, HSQC and HMBC experiments), mass spectrometry (HR-ESI-MS) and by comparison with literature data. The inhibitory activity of all isolated compounds was evaluated against promyelocytic leukemia HL60 and human erythromyeloblastoid leukemia K562 cell lines and seven of these compounds exhibited a weak cytotoxicity with IC<sub>50</sub> values ranging from 40 to 97 μM.</p
