POLYMERIC COPPER (II) PHOSPHATES INCORPORATING 4-PYRIDYL
(TERPYRIDINE). STRUCTURAL STUDIES AND ANTICANCER ACTIVITY
Gulzar A. Bhat and R. Murugavel*
Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
Copper phosphates have found extensive applications as functional models for hydrolases involved in
phosphate ester hydrolysis.1 Several copper complexes have been used in anticancer therapy however
there are no reports involving copper phosphates.2 In this study neutral copper(II) phosphate based Ndonor metallo-ligands, [Cu(X-dipp)(Pyterpy)]2 [X=H (1), Br (2)] exemplifying expanded 4,4'-bipyridine
have been synthesized by reacting
pytpy (pytpy = 4ꞌ-(4-pyridyl)-2,2':6ꞌ,2ꞌꞌ-terpyridine) and para
substituted 2,6-diisopropylphenyl phosphate (X-dippH2) with copper acetate at room temperature.
However, when the reaction is carried out at higher temperature (100˚C), one dimensional polymers,
[Cu2(X-dippH)(X-dipp)( Pyterpy)(H2O)]n (X= Cl, 3 X= Br 4 X=I, 5) with box-like repeating unit
possessing distorted square pyramidal and octahedral copper centres were isolated. Various in vitro DNA
and protein cleavage assays revealed that complexes 1 and 2 have significant nuclease and protease
activities. Moreover, MTT assay and propidium staining depicted that both complexes 1 and 2 have antiproliferative effects in human colon and breast cancer cell lines. However, Complex 1 due to high affinity
for DNA proved more potent than complex 2 in terms of its higher cytotoxicity at lower dosage. Thus,
overall our results suggest that complexes 1 and 2 may find applications as anti-tumor therapeutics after
further in-vivo trials.
Figure: (a) Molecular structure of 2; (b) Molecular structure of 2 and (c) Propidium staining of complex 1 and 2
treated HCT-116.
References:
1. Murugavel, R.; Walawalker, M. G.; Pothiraja, R.; Rao, C. N. R.; Choudhury, A. Chem. Rev. 2008,
108, 3549.
2. Grau, J.; Brissos, R. F.; Uber, J. S.; Caballero, A.; Caubet, A. B.; Roubeau, O.; Gregório, L.
K.; Tomás, R. P.; Gamez, P. Dalton Trans., 2015, 44, 16061.