Tetra‐ to Dodecanuclear Oxomolybdate Complexes with Functionalized Bisphosphonate Ligands: Activity in Killing Tumor Cells

Abstract

We report the synthesis and characterization of five novel Mo-containing polyoxometalate (POM) -bisphosphonate complexes with nuclearities ranging from 4 to 12 and with either fully reduced, fully oxidized or mixed valence (Mo V , Mo VI ) molybdenum in which the bisphosphonates bind to the POM cluster via their two phosphonate groups as well as a deprotonated 1-OH group. (5) are alkali salts of, respectively, fully reduced octanuclear and fully oxidized dodecanuclear POMs. The activities of 2-5 (which are water soluble) against three human tumor cell lines were investigated in vitro. 2-4 had weak but measurable activity but 5 had IC 50 values of ~10 μM, about four times the activity of the parent alendronate molecule, on a per-alendronate basis, opening up the possibility of the development of novel drug leads based on Mo-bisphosphonate clusters.

Covalent Attachment of Thiophene Groups to Polyoxomolybdates or Poly­oxotungstates for the Formation of Hybrid Films

“…The P 2 N salts (P 2 N) 8 The IR spectrum of (P 2 N) 8 (H 3 O) 6 Ni 7 (AleThio) 2 can be viewed as the superimposition of the IR spectra of (P 2 N)Cl and Ni 7 (AleThio) 2 ( Figure S5). It can be noted that, as observed for other dodecanuclear Mo VI complexes with covalently grafted functionalized alendronate ligands, [13] the pale yellow crystals of Na 1.5 …”

“…The coupling constant J = 40.2 Hz is in agreement with other Mo 12 (BP) 4 derivatives. [13,14] However its stability is limited for pH higher than 4. Indeed, as the pH increases ( Figure S3), two peaks of inequivalent intensities characteristic of Mo 6 (BP) 2 species appear, [12,13] showing the evolution of Mo 12 (AleThio) 4 .…”

“…[10] Three polyoxomolybdates have been isolated with Mo VI ions and alendronate ligands [R = (CH 2 ) 3 NH 2 , Ale, Scheme 1], which formation is highly dependent of the pH value: at pH = 7.5 the mononuclear POM [(MoO 2 )(Ale) 2 ] 6-[Mo(Ale) 2 ], [11] at pH = 4.5 the hexanuclear [(Mo 3 O 8 ) 2 O-(Ale) 2 ] 6-[Mo 6 (Ale) 2 ], [12] and at pH = 3.0 the dodecanuclear [(Mo 3 4 ]. [13] This family of hybrid POMs possesses both photochromic [13] and anticancer properties. [12,13] We have then turned to the phosphotungstate POMs and investigated the reactivity of the trivacant [PW 9 14-(M = Co, [14] Ni [15] ) have thus been synthesized.…”

“…[13] This family of hybrid POMs possesses both photochromic [13] and anticancer properties. [12,13] We have then turned to the phosphotungstate POMs and investigated the reactivity of the trivacant [PW 9 14-(M = Co, [14] Ni [15] ) have thus been synthesized. Both anions exhibit single molecule magnet behaviour.…”

Self-Assembly in Polyoxometalate and Metal Coordination-Based Systems: Synthetic Approaches and Developments

“…Initial exploration of the parameter space (pH, concentration, counterions effect, ionic strength, etc.) yielded a large variety of compounds with different properties which can interact with biological systems [62][63][64][65][66][67].…”