Related Experiment Video
Updated: Feb 14, 2026

Functionalized Spirocyclic Heterocycle Synthesis and Cytotoxicity Assay
Published on: February 9, 2021
A family of manganese complexes containing heterocyclic-based ligands with cytotoxic properties
Jessica Castro1, Ester Manrique2, Marlon Bravo1
1Laboratori d'Enginyeria de Proteïnes, Departament de Biologia, Facultat de Ciències, Universitat de Girona, Campus de Montilivi, C/Maria Aurèlia Capmany, 40, E-17003 Girona, Spain; Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Girona, Spain.
Abstract:
We describe the synthesis of three new manganese (II) complexes containing the bidentate ligands 2-(1-methyl-3-pyrazolyl)pyridine (pypz-Me) and ethyl 2-(3-(pyridine-2-yl)-1H-pyrazol-1-yl)acetate (pypz-CH2COOEt), with formula [MnX2(pypz-Me)2] (X = Cl-1, CF3SO3-2) and [Mn(CF3SO3)2(pypz-CH2COOEt)2] 3. Complexes 1-3 have been characterized through analytical, spectroscopic and electrochemical techniques, as well as by monocrystal X-ray diffraction analysis. The complexes show a six-coordinated Mn(II) ion though different stereoisomers have been isolated for the three compounds. Complexes 1-3, together with the previously described compounds [MnCl2(pypz-H)2] 4, [Mn(CF3SO3)2(pypz-H)2] 5, [Mn(NO3)2(pypz-H)2] 6, [MnCl2(H2O)2(pypz-H)2] 7 (pypz-H = 2-(3-pyrazolyl)pyridine) and ([Mn(CF3SO3)2((-)-L)2] 8, ((-)-L = (-)-pinene[5,6]bipyridine), were tested in vitro for cytotoxic activity against NCI-H460 and OVCAR-8 cancer cell lines. The geometry of a specific compound does not seem to influence its activity in a significant extent. However, among the tested compounds those that display hydrophobic substituents on the pyrazole ring and triflate ions as labile ligands show the best antiproliferative properties. Specifically, compound 8 containing the pinene-bipyridine ligand presents an antiproliferative activity similar to that of cisplatin and higher than that of carboplatin, and displays selectivity for tumour cells. Its antiproliferative effect is due to the generation of ROS species that allow the compound to interact with DNA.
More Related Videos
Related Concept Videos
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Protein Families
Gene Families
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Gene Families
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...

