Department of Chemistry, Punjab Agricultural University, Ludhiana, India
Abstract:
Two new guaianolides have been isolated from Saussurea lappa as minor components and have been named isodehydrocostus lactone and isozaluzanin C. A structure has been assigned to isodehydrocostus lactone on the basis of spectral data and correlation with estafiatin. The 1H NMR data and dehydrogenation studies show that the other highly crystalline guaianolide is isomeric with zaluzanin C. Earlier 3β-H-zaluzanin C has however been reported to occur as a colourless oil.