Two new myrinsol diterpenoids, euphordracunculins A（1） and B（2）, together with three known analogues, euphorprolitherin B（3）, proliferins A（4） and B（5）,were isolated from the petroleum ether extract of the aerial parts of Euphorbia dracunculoides Lam. Their structures were elucidated by means of extensive spectroscopic analysis（NMR and ESI-MS） and comparison with data reported in the literature.
Li WangZhen ZangYu-Fei WangSheng-Xiong HuangPei CaoYong Zhao
[Objective] The aim was to study the chemical constituents of Euphorbia hirta. [Method] The constituents were isolated and purified by various chromatography methods including normal phase and reverse phase silica gel as well as Sephadex LH-20 gel column, and then elucidated by spectroscopic analysis such as MS and NMR etc. Compounds 1, 4, 5 and 6 were evaluated for their immunostimulatory activity against splenic cell of mouse by FCM. [Result] Six compounds were isolated from Euphorbia hirt, and identified as diisobutyl-O-phthalate （compond 1）, diethylhexyl phthalate （compond 2）, hispidulin （compond 3）, acetyl peroxide （compond 4）, quercetein （compond 5） and gallic acid （compond 6）. All compounds were inactive against splenic cell of mouse. [Conclusion] Compounds 1, 2 and 3 were isolated from this plant for the first time, and compound 4 was the first naturally occurring compound. This study provided reference for isolating bioactive substances from Euphorbia hirta.
