Planta Medica International Open 2017; 4(S 01): S1-S202
DOI: 10.1055/s-0037-1608192
Poster Session
Georg Thieme Verlag KG Stuttgart · New York

ANTIPROTOZOAL SESQUITERPENE LACTONES AND OTHER CONSTITUENTS FROM Schkuhria pinnata, Tarchonanthus camphoratus AND Vernonia lasiopus

N Kimani
1   Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Münster, PharmaCampus, Corrensstraße 48, Münster D-48149, münster, Germany
,
J Matasyoh
2   Department of Chemistry, Egerton University, P.O. Box 536, Egerton 20115, Egerton, Kenya
,
M Kaiser
3   Swiss Tropical and Public Health Institute (Swiss TPH), Socinstr. 57, Basel CH-4051, Basel, Switzerland
4   University of Basel, Petersplatz 1, Basel CH-4003, Basel, Switzerland
,
R Brun
3   Swiss Tropical and Public Health Institute (Swiss TPH), Socinstr. 57, Basel CH-4051, Basel, Switzerland
4   University of Basel, Petersplatz 1, Basel CH-4003, Basel, Switzerland
,
T Schmidt
1   Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Münster, PharmaCampus, Corrensstraße 48, Münster D-48149, münster, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
24 October 2017 (online)

 

In our continued search for new antiprotozoal agents in plants of the family Asteraceae [1], we have investigated Schkuhria pinnata, Tarchonanthus camphoratus and Vernonia lasiopus. Bioassay-guided chromatographic fractionation and isolation from the dichloromethane extracts of the three plants led in addition to pectolinarigenin (5) and benzenepropanol (18) to the identification of three new (13,14, 20) and 18 known sesquiterpene lactones (STLs) from S. pinnata. Six elemanolide type STLs (25 – 30) from V. lasiopus and two further STLs from T. camphoratus (1 – 2) were also isolated (Figure 1). The compounds were identified by HR-MS and 1D and 2D NMR in comparison with literature data [2,3]. All these compounds showed interesting in vitro anti-trypanosomal activity. Compounds (19) was the most active from S. pinnata with an IC50 value of 0.10µM against Trypanosoma brucei rhodesiense (Tbr) trypomastigotes and selectivity index (SI) of 21.5. From T. camphoratus, 3-oxo-1,2-dehydrocostic acid (2) displayed interesting activity with IC50 values of 2.8µM and 0.18µM against Tbr and axenic grown L.donovani amastigotes and SI values of 6.2 and 95.4 respectively. Vernolepin (26), from V. lasiopus, displayed an IC50 value of 0.19µM against Tbr and an SI value of 14.5. In vivo tests and determination of vernolepin (26) mechanism of action are currently in progress. To the best of our knowledge, elemanolides have not previously been reported to possess anti-trypanosomal activity. These bioactivity data complement previous data obtained in our group and give more insights into the structure- anti-trypanosomal activity relationships of STLs [1].

Zoom Image
Fig. 1: Compounds isolated from T. camphoratus (1 – 2), S. pinnnata (3 – 24) and V. lasiopus (25 – 30)

[1] Schmidt, T. J. et al. Antimicrob. Agents Chemother. 2014, 58, 325 – 332.

[2] Ganzer, U. et al. Phytochemistry 1990, 29, 535 – 539.

[3] Jakupovic, J. et al. Planta Med. 1985, 51, 378 – 380.