Mass Spectrometry Techniques ESI and MALDI in Characterization of Colchicine and Colchiceine Complexes

Abstract

Complexes are biologically useful compounds and they have many biological activities. Many different inorganic and organic compounds can form stable complexes. Complexes of organic compounds, in which ligands are biologically active part, for example alkaloids, are especially interesting for researchers. Alkaloids: Colchicine and colchiceine can form stable complexes with alkali metals. A series of complexes of both alkaloids have been obtained and studied by ESI MS, MALDI MS, ¹H and ¹³C NMR, FT IR, DFT and PM5/PM7 calculations and molecular modelling. These complexes also have been tested against fungicidal and cytotoxic activity.

The colchicine complexes with Li⁺, Na⁺, K⁺ cations of different salts have been studied in details by MALDI and ESI mass spectra. In the ESI MS mass spectra has been shown that colchicine forms stable complexes of 1:1 stoichiometry with monovalent and divalent metal cations. Also formation of complexes of various stoichiometry has been detected. Colchicine complexes have not been characterised by modern mass spectra methods such as MALDI MS. The aim of this study was to summarize ESI MS study on colchicine and colchiceine complexes and check fragmentation pathways of colchicine complexes with alkali metals by MALDI MS mass spectra.