Résumé
Objective: To study the low polar chemical constituents from Leonurus japonicus. Methods: The chemical constituents were isolated and purified by various chromatographic methods including column chromatography over silica, Sephadex LH-20, and Rp C18 columns. Their structures were identified by physicochemical properties and spectroscopic analysis. Results: Six aliphatic compounds were isolated from the EtOAc extracts of L. japonicus, including two allenes: (-)-nonadeca-5,6-dienoic acid methyl ester (1) and methyl octadeca-5,6-dienoate (2); four saturated aliphatic compounds: heneicosanoic acid (3), arachidic acid (4), heptacosanoic acid (5), and methyl myristate (6). Conclusion: All the compounds are isolated from L. japonicus for the first time. Compound 1 is a new one named leonuallenote A, while compound 2 is first reported from the plants of Leonurus L.