A new Labdane Diterpene and Other Constituents from Marrubium deserti Noe ex coss

The phytochemical study of the chloroform soluble part of the hydroalcoholic extract of Marrubium deserti allowed us to describe a new labdane diterpene, 6-dehydroxy-19-acetyl-marrubenol (3) beside three other diterpenes : 19-acetyl-marrubenol (6) , 6-acetyl-marrubenol (7) and 16-epoxy-9-hydroxy-labda-13(16), 14- diene (1). This latter derivative is described for the first time as natural compound. Phytol (2), and three sterols: b -sitosterol (4), stigmasterol (5) and b -sitosterol 3-O-glucoside (8) were also isolated from this species. Structure elucidation of the isolated compounds was accomplished by means of spectroscopic techniques, especially NMR spectroscopy and mass spectrometry.