Alkaloid from Colchicum species in complexes with lithium, sodium, potassium and magnesium cations– spectroscopic characterization, semiempirical and theoretical calculation, fungicidal and cytotoxic activity

Abstract

The colchicine (1:1) complexes with monovalent cations: Li+, Na+ and K+ as well as divalent cation Mg2+ of nitrate salts were synthesized and characterized by 1H and 13C NMR, FT-IR, UV–Vis, ESI-MS, spectroscopic methods and elemental analysis. In the ESI-MS mass spectra (in ES+ mode) formation of complexes of different stoichiometry 1:1, 2:1, 3:1, (colchicine – metal cation) was detected and in complexation process nitrate anions are also involved. Stoichiometry 1:1:1, 1:2:1, 2:1:1 and 2:2:1 (colchicine – metal cation – nitrate anion) of colchicine complexes with nitrate salts were also detected. The structures of the colchicine complexes with Li+, Na+, K+ and Mg2+ cations are discussed in details by PM5 semiempirical calculations, DFT, M06-2X theoretical calculations, molecular dynamics (MD) simulations and molecular modelling. Complexes were also screened against fungicidal and cytotoxic activity. The antifungal activity of colchicine and all complexes was assayed in vitro against eight fungi species. Cytotoxic activity of all complexes was tested against ovarian cancer cell SKOV-3 line.