Triplex-forming oligonucleotides can target specific DNA sequences by binding in the duplex major groove. Chemical modifications and ligand binding have been explored, for use in a variety of biological applications.

Malignant tumors have affected the human being since the pharaoh period, but in the last century the incidence of this disease has increased due to a large number of risk factors, including deleterious lifestyle habits (i.e., smoking) and the higher longevity. Many efforts have been spent in the last decades on achieving an early stage diagnosis of cancer, and more effective cures, leading to a decline in age-standardized cancer mortality rates. In the last years, our research groups have developed new metal-based complexes, with the aim to obtain a better selectivity for cancer cells and less side effects than the clinically established reference drug cisplatin. This work is focused on four novel Au(III) and Ru(III) complexes that share the piperidine dithiocarbamato (pipe-DTC) as the ligand, in a different molar ratio. The compounds [AuCl2(pipeDTC)], [Au(pipeDTC)2]Cl, [Ru(pipeDTC)3] and β-[Ru2(pipeDTC)5] have been synthesized and fully characterized by several chemical analyses. We have then investigated their biological properties in two different cell lines, namely, AGS (gastric adenocarcinoma) and HCT116 (colon carcinomas), showing significant differences among the four compounds. First, the two gold-based compounds and β-[Ru2(pipeDTC)5] display IC50 in the µM range, significantly lower than cisplatin. Second, we showed that [AuCl2(pipeDTC)] and β-[Ru2(pipeDTC)5]Cl drive different molecular mechanisms. The first was able to induce the protein level of the DNA damage response factor p53 and the autophagy protein p62, in contrast to the second that induced the ATF4 protein level, but repressed p62 expression. This study highlights that the biological activity of different complexes bringing the same organic ligand depends on the electronic and structural properties of the metal, which are able to fine tune the biological properties, giving us precious information that can help to design more selective anticancer drugs.

Four propargyl O -glycosides derivatized with mannose, glucose, and fructose moieties were synthesized and then incorporated within a diiron structure as part of a vinyliminium ligand. Hence, six glycoconjugated diiron complexes, [ 2–5 ]CF 3 SO 3 (see Scheme 1) and the nonglycosylated analogues [ 6a–b ]CF 3 SO 3 , were obtained in high yields and unambiguously characterized by elemental analysis, mass spectrometry, and IR and multinuclear NMR spectroscopies. All compounds exhibited a significant stability in DMSO- d 6 /D 2 O solution, with 63–89% of the complexes unaltered after 72 h at 37 °C and also in the cell culture medium. The cytotoxicity of [ 2 – 6 ]CF 3 SO 3 , as well as that of previously reported 7 and 8 , was assessed on CT26 (mouse colon carcinoma), U87 (human glioblastoma), MCF-7 (human breast adenocarcinoma), and RPE-1 (human normal retina pigmented epithelium) cell lines. In general, the IC 50 values correlate with the hydrophobicity of the compounds (measured as octanol–water partition coefficients) and do not show an appreciable level of selectivity against cancer cells with respect to the nontumor ones.

Novel diiron vinyliminium complexes, [Fe2Cp2(CO)(μ-CO){μ-C(R3)=CHC=NMe(R2)}]CF3SO3 (2a-f; R2 = 4-C6H4OMe, Cy or Me; R3 = Cy, CH2Cy or 4-C6H4OMe; Cy = cyclohexyl, Cp = η5-C5H5), were synthesized by alkyne insertion reaction...

No abstract