Cytotoxic dimeric quinolone–terpene alkaloids from the root bark of Zanthoxylum rhetsa

• Published in: Phytochemistry (Oxford) 2014-07, Vol.103, p.8-12
• Main Authors: Ahsan, Monira, Haque, Mohammad Rashedul, Hossain, Md. Belayet, Islam, Sheikh Nazrul, Gray, Alexander I., Hasan, Choudhury Mahmood
• Format: Article
• Language: English
• Subjects: 2,11-Didemethoxyvepridimerine; 2′-Episimulanoquinoline; Alkaloids - chemistry; Alkaloids - pharmacology; Cell Line, Tumor; Cell Survival - drug effects; Chelerybulgarine; Dihydrochelerythrine; Humans; Molecular Structure; Plant Bark - chemistry; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Roots - chemistry; Rhetsidimerine; Zanthoxylum - chemistry
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2014.03.008

Four quinolone–terpene alkaloids, chelerybulgarine (1), 2′-episimulanoquinoline (3), 2,11-didemethoxyvepridimerine B (4), and rhetsidimerine (5) were isolated from the root bark of Zanthoxylum rhetsa DC. •Four quinolone–terpene alkaloids were characterised.•The C5 units of the two 2-quinolone units joined in a different manner leaving a 2-methyl-2-propene chain in rhetsidimerine.•The isolated compounds were tested for cytotoxicity against a panel of six human stomach cancer cell lines. Four quinolone–terpene alkaloids, chelerybulgarine (1), 2′-episimulanoquinoline (3), 2,11-didemethoxyvepridimerine B (4), and rhetsidimerine (5) were isolated from the root bark of Zanthoxylum rhetsa DC. Chelerybulgarine (1) is a C–C linked terpene alkaloid where the C-6 of dihydrochelerythrine is linked to C-11 of the sesquiterpenoid 10β-methoxybulgarene. 2′-Episimulanoquinoline is a dimeric alkaloid containing dihydrochelerythrine and 8-methoxy-N-methylflindersine moieties, whereas 2,11-didemethoxyvepridimerine B and rhetsidimerine are dimeric prenylated quinolone alkaloids. Seven of the isolated compounds exhibited weak cytotoxicity when tested against a panel of six human stomach-cancer cell lines.