Leonurus marrubiastrum

Harwickiic acid, the lactone (25), and the acid (26) have been isolated from Printzia laxa (Compositae). Marrubiastrol (27), aldehydomarrubialactone (28), and the 20-nor-8-ketone desmethylmarrubiaketone are three new diterpenoid lactones which were obtained from Leonurus marrubiastrum (Labiatae). Their structures were determined by a combination of H and n.m.r. and X-ray methods. A full paper has appeared describing the structures of floribundic acid. 

Erspamer, V. 1948. Ricerche farmacologiche sul Leonurus cardiaca L. (e sul Leonurus marrubiastrum L). Arch. Int. Pharmacodynam. Ther. 76(1) 132-152. 

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