Problems related to the isotachophoresis technique employed for separation and determination of alkaloids used in the treatment of malaria

Abstract

Each year about 250 million people around the world are infected with parasites from the Plasmodium group causing malaria. Although more than 50 antimalarials are currently being tested, cinchona tree alkaloids in the form of quinoline derivatives are still used to treat the disease. The objective of this work was to develop and apply a novel method for separation and determination of six biologically active alkaloids using isotachophoresis. The following derivatives were involved in the study: quinine, quinidine, cinchonine, cinchonidine, acetylcinchonine, and acetylquinidine. Successful application of isotachophoresis for the separation of these diastereoisomers required a new terminating electrolyte. The developed method allows for separation of the above-mentioned alkaloids in less than 33 minutes. Linear regression coefficients were high and ranged from 0.9995 to 0.9999. Relative standard deviation did not exceed 5%, and the standard measurement uncertainty was below 3 μgL⁻¹. The new method was then successfully used to determine quinine content in selected products.

Graphical Abstract

Keywords:

• Malaria
• quinine
• quinoline derivatives
• determination
• separation techniques
• isotachophoresis

Acknowledgments

The authors are cordially indebted to Prof. N. Erchak for ma king available the use of 4,4′-bis[(1-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at], which was the main component of the terminating electrolyte.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by Ministry of Science and Higher Education.