Structural elucidation and evaluation of toxicity and antitumor activity of cardiac glycosides isolated from Leptadenia pyrotechnica

Abstract

Investigation of the chemical constituents of Leptadenia pyrotechnica (Forsk.) Decne (Asclepiadaceae) led to the isolation of three cardiac glycosides; 14,19-dihydroxycard-20 (22)-enolide-3-O-[β-d-glucopyranosyl-β-d-digitoxoside] C-I, 14,19-dihydroxycard-20 (22)-enolide-3-O-[β-d-glucopyranosyl-β-d-glucopyranoside] C-II and 14,19-dihydroxycard-20 (22)-enolide-3-O-β-d-digitoxoside C-III. The isolation and identification of these compounds were carried out using rotation locular counter current chromatography (RLCCC), high performance liquid chromatography (HPLC). The structures of the isolated compounds were established by fast-atom bombardment (FAB) and electrospray ionization (ESI) mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic analysis. The acute toxicity studies of the cardiac glycosides and total alcohol extracts were examined by brine shrimp. Their lethal concentration 50 (LC₅₀) were 18.84 and 11.89 ppm, respectively. The antitumor activity potato disk assays of the cardiac glycosides and total alcohol extracts had shown good activity − 30.8% and 49.3%, respectively.

Keywords::

• Leptadenia pyrotechnica
• Asclepiadaceae
• brine shrimp
• antitumor activity
• digitoxoside
• cardiac glycosides and RLCCC

Acknowledgements

AMYM is grateful to the Egyptian Ministry of higher Education, and the Environmental Chemistry and Toxicology Laboratory, Texas Southern University, Houston, for the Fellowship it has provided her with to undertake this work.

Declaration of interest: This work was supported by RCMI grant number R003045-17A and NASA/URC grant number NCC 9.165. The authors alone are responsible for the content and writing of the paper.