Artabolide, a novel polar auxin transport inhibitor isolated from Artemisia absinthium.

Abstract: A new sesquiterpene with an α-methylene-γ-lactone moiety, artabolide (1), and three known derivatives 2–4 were isolated from Artemisia absinthium. The structure of 1 was elucidated by 1D and 2D NMR analyses, and the absolute configuration was determined using the modified Mosher's method and X-ray crystal structural analysis. Approximately 2.5 μg/plant treatment of artabolide (1) exhibited ca. 50% inhibition of polar auxin transport in radish hypocotyls, while 2–4 showed no significant inhibitory activity. Therefore, these results support the importance of the α-methylene-γ-lactone moiety for the inhibition of polar auxin transport. [Copyright &y& Elsevier]