An Unusual 2,3-Secotaraxerene and Other Cytotoxic Triterpenoids from Pleiocarpa pycnantha (Apocynaceae) Leaves Collected from Nigeria

Molecules

Olubunmi A. Omoyeni¹  Mervin Meyer²  Emmanuel Iwuoha¹  Ivan Green¹ 

[1] Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa;Department of Biotechnology, Apoptosis Research Unit, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa

关键词: Pleiocarpa pycnantha;    Apocynaceae;    triterpenoids;    cytotoxicity;    2;    3-seco-taraxerene;    ursolic acid;    WST-1;   

DOI  :  10.3390/molecules19033389

来源: mdpi

【 摘 要 】

Three known triterpenoids, namely ursolic acid (1), and the 27-E- and 27-Z-p-coumaric esters of ursolic acid (compounds 2, 3), were isolated together with a new triterpene 2,3-seco-taraxer-14-en-2,3-lactone [pycanocarpine (4)] from an ethanolic extract of Pleiocarpa pycnantha leaves. The structure of 4 was unambiguously assigned using NMR, HREIMS and X-ray crystallography. The cytotoxic activities of the compounds were evaluated against HeLa, MCF-7, KMST-6 and HT-29 cells using the WST-1 assay. Ursolic acid (1) displayed potent cytotoxic activity against HeLa, HT-29 and MCF-7 cells with IC₅₀ values of 10, 10 and 20 µM respectively. The new compound 4 and its hydrolysed derivative 5 were selectively cytotoxic to the breast cancer cell line, MCF-7 with IC₅₀ values 20 and 10 µM respectively. This is the first report on isolation of a 2,3-seco-taraxerene derivative from the Apocynaceae family and cytotoxic activityof P. pycnantha constituents.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.