Phytochemical study and cytotoxicity evaluation of Colchicum stevenii Kunth (Colchicaceae): A Jordanian meadow saffron

Abstract

Isolation, characterization, and biological evaluation of active components of Colchicum stevenii Kunth (Colchicaceae) are described. Colchicum stevenii is an unexplored Jordanian specie with toxic reputation. Directed by brine shrimp lethality test (BST), methanolic extraction, liquid–liquid partition, preparative TLC, and semi-preparative HPLC, it resulted in the isolation of six cytotoxic compounds. The compounds, reported for the first time from this specie, are: (−)-colchicine (1), 2-demethyl-(−)-colchicine (2), (−)-cornigerine (3), β-lumicolchicine (4), (−)-isoandrocymbine (5) and (−)-O-methylandrocymbine (6). A new, in-house developed, acidic-based reverse-phase gradient semi-preparative HPLC method for the separation of colchisides is presented here. Structural elucidation was based on spectroscopic techniques principally; ¹H-NMR and low resolution EIMS. Based on BST results, reported as LC₅₀ values in µg mL⁻¹ (ppm) with 95% confidence intervals, (−)-colchicine (2.5 ppm) and (−)-cornigerine (2.7 ppm) were the most potent.

Keywords:

• Colchicum stevenii
• Colchicine
• Alkaloids
• Jordan medicinal plants
• Cytotoxicity
• Brine shrimp lethality test

Acknowledgements

The authors would like to thank Mr Faroq Zghol and Ead Himza for their technical help. Thanks also are due to the Deanship of Scientific Research, Jordan University of Science and Technology, Irbid, Jordan for financial help.