Cytotoxicity of a new tirucallane derivative isolated from Stereospermum acuminatissimum K. Schum stem bark

Abstract

One new tirucallan derivative, leutcharic acid (1) was isolated from Stereospermum acuminatissimum stem bark together with the known compounds 3-oxo-22-hydroxyhopane (2), 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid (3), 3-oxotirucalla-7,24-dien-21-oic acid (7), lupeol (4), β-sitosterol (5) and stigmasterol (6). The structures of the isolated compounds were elucidated using 1 D and 2 D NMR spectroscopy in combination with literature data. To the best of our knowledge, this is the first report on the cytotoxic properties’ constituents of S. acuminatissimum. Cytotoxicity of compounds 1 and 2 was assessed in vitro with the WST-1 assay on human lung adenocarcinoma A549 and THP-1 human monocytic leukaemia cell lines. Both compounds showed antiproliferative activity on the cancer cells. Compound 2 was more active against THP-1 with an IC₅₀ value of 26.83 µM. The sensitivity of THP-1 cells to compounds 1 and 2 indicated that these compounds might be potential leads for anticancer agent development against leukaemia.

Graphical Abstract

Keywords:

• Triterpene
• Stereospermum acuminatissimum
• cytotoxicity
• antiproliferative activity

Acknowledgements

AML and DKS would like to thank Alexander von Humboldt-Stiftung for support through Georg Forster Fellowship for Experienced Researchers re-invitation (ID N° 1137675) at the University of Bielefeld (Germany). The biological part of this work was supported by the Laboratory of Pharmaceutical Technology, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne. Grateful acknowledgment is also made to the Swiss National Foundation for providing financial support to JPD through the project n° IZSEZO_180383/1.

Disclosure statement

No potential conflict of interest was reported by the author(s).