Phenylbenzofuran-type stilbenoids from Stemona species

• Published in: Phytochemistry letters Vol. 9; pp. 33 - 36
• Main Authors: Zraunig, Andrea, Pacher, Thomas, Brecker, Lothar, Greger, Harald
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2014
• Subjects: Phenylbenzofurans; Stemona burkillii; Stemona collinsiae; Stemona involuta; Stemona lucida; Stilbenoids; Stemona involuta; Stemona lucida; Stilbenoids; Stemona collinsiae; Phenylbenzofurans; Stemona burkillii
• ISSN: 1874-3900; 1876-7486
• DOI: 10.1016/j.phytol.2014.04.007

•Five new phenylbenzofurans, the stemofurans S-W, were isolated and identified.•Four types of stilbenoids were detected in Stemona species from Thailand and Australia.•All compounds are characterized by rare C-methylation of the aromatic rings.•Additional hydroxylation at C-4′ leads to biosynthetically unusual substitution patterns. Five new phenylbenzofuran-type stilbenoids, stemofurans S-W (1–5), were isolated from underground parts of four Stemona species collected in Thailand and Australia together with the known stemofurans A–C, G, E, J, M, the stilbostemins A–D, F, the stemanthrenes A–D, dihydropinosylvin, pinosylvin, and 4′-methylpinosylvin. The chemical structures of the new compounds were elucidated by 1H NMR and 13C NMR spectroscopy and mass spectrometry. In accordance with previous reports all compounds were characterized by C-methylations of the aromatic rings. Stemofurans S (1) and U (3) showed an unusual hydroxylation at position C-4′, a hitherto unknown substitution of Stemona stilbenoids.