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Z. Naturforsch.
69c, 191 – 198
(2014)
doi:10.5560/ZNC.2014-0011
Cytotoxic Saponins from the Seeds of Pittosporum angustifolium
1 Department of Pharmaceutical Biology, Institute of Pharmacy, Ernst Moritz Arndt University Greifswald, Friedrich-Ludwig-Jahn-Straße 17, D-17489 Greifswald, Germany. Fax: +49(0)3834864885. E-mail:
cbaecker@uni-greifswald.de
2 Department of Pharmaceutical Biology, Institute of Pharmacy, Free University of Berlin, Königin-Luise-Str. 2 + 4, D-14195 Berlin, Germany
3 AnalytiCon Discovery GmbH, Hermannswerder Haus 17, D-14473 Potsdam, Germany
4 Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Ernst Moritz Arndt University Greifswald, Friedrich-Ludwig-Jahn-Straße 17, D-17489 Greifswald, Germany
*Author for correspondence and reprint requests
Received January 18 / April 23, 2014 / published online June 5, 2014
Three new acylated R1-barrigenol triterpene glycosides, 1–3, were isolated from the seeds of Pittosporum angustifolium Lodd. together with four known glycosides, 4–7, containing R1- and A1-barrigenol backbones. On the basis of spectroscopic, spectrometric, and chemical analyses the novel compounds were named pittangretosides N–P and established as 21β-acetoxy-22α-angeloyloxy- (1), 21β-acetoxy-22α-(2-acetoxy-2-methylbutyroyloxy)- (2), and 21β-(2-me-
thylbutyroyloxy)-22α-acetoxy-3β-[β-d-glucopyranosyl-(1→2)]-[α-l-arabinopyranosyl-(1→3)]-[α-
l-arabinofuranosyl-(1→4)]-β-d-glucuronopyranosyloxyolean-12-ene-15α,16α,28-triol (3). Evaluation of the in vitro cytotoxicity against three tumour cell lines and one non-tumourigenic cell line revealed antiproliferative effects with IC50 values in a range of 1.74–34.1μm.
Key words: Pittosporum angustifolium, Triterpene Glycosides