Complexes of cerium(III), lanthanum(III) and neodymium(III) with 4-methyl-7
-hydroxycoumarin (Mendiaxon, Hymecromone) were synthesized by the mixing of
equimolar amounts of the respective metal nitrates and 4-methyl-7-hydroxyc
oumarin sodium salt in water. The complexes were characterized and identifi
ed by elemental analysis, conductivities, IR, H-1 and C-13 NMR spectroscopi
es and mass spectral data. DTA and TGA have been applied to study the compo
sitions of the compounds. The newly synthesized compounds were assayed for
acute intraperitoneal and per oral toxicity, influence on blood clotting ti
me and the most active complex was investigated for spasmolytic activity. T
he complexes of cerium(III) and neodymium(III) showed marginal cytotoxic ac
tivity against transformed leukemic cell lines (P3HR1 and THP-1) as compare
d to the inorganic salts. (C) 2001 Editions scientifiques et medicales Else
vier SAS.