A new dinuclear platinum complex with a nitrogen-containing geminal bisphosphonate as potential anticancer compound specifically targeted to bone tissues

Platinum–bisphosphonate complexes have proven to be inactive chemotherapeutics targeted for malignant mesothelioma because of inappropriate hydrolysis

“…The structure in which one bisphosphonate unit bridges two platinum atoms in a W conformation is fully supported by the presence of only one signal in the 31 P{ 1 H} spectrum and of two signals in the 195 Pt spectrum [10,11,13,14]. The plane of symmetry passing through the two platinum and the phosphonate carbon atom renders the two phosphorus atoms chemically equivalent.…”

“…S5) shows a signal with unresolved platinum satellites at 33.27 ppm (platinum satellites are usually very broad due to chemical shift anisotropy, CSA, relaxation of phosphorus nuclei which are magnetically equivalent and shifted at lower field (Δδ = 20.17) with respect to the free HPMBP ligand at the same pH* [11].…”

“…The 31 P-NMR spectrum (Fig. S3) shows a signal with unresolved platinum satellites at 33.69 ppm assigned to the two phosphorus nuclei which are magnetically equivalent and shifted at lower field (Δδ = 20.86) with respect to the free HPMBP ligand at the same pH* [11]. The 195 Pt-NMR of 3a (Fig.…”

“…Some (Pt-n-BP)s have already been investigated as specific bonetargeted antineoplastic drug candidates [10][11][12][13][14]. We report here the synthesis of new di-platinum complexes containing am(m)ine ligands (A) and a n-BP moiety as a bridging ligand (Fig.…”

“…Chemical shifts are given in ppm. 1 H chemical shifts were referenced to internal sodium 3-(trimethylsilyl)propionate (TSP), 31 P chemical shifts were referenced to external H 3 PO 4 (85% w/w), and 195 Pt chemical shifts were referenced to external K 2 [16], and tetrasodium 1-(pyridin-4-yl)-1-hydroxymethane-1,1-diyl-bisphosphonate (3,Na 4 [HPMBP]) [11] were prepared following already reported procedures. The elemental analyses and the spectroscopic characteristics of the synthesised geminal bisphosphonates (or their corresponding acids) were consistent with the data reported in the literature.…”