Natural and anthropogenic sources of chromium, nickel and cobalt in soils impacted by agricultural and industrial activity (Vojvodina, Serbia).

This study reports the contents and sources of chromium, nickel and cobalt, as well as Al, Ca, Mg, K, Fe and Mn in Vojvodina regions Srem and Central Banat area soil samples. Different methods were applied to identify the sources of the studied elements and to classify the latter as geogenic and/or anthropogenic: modified Tessier sequential extraction, calculation ratio of E/Al, XRPD, correlations and cluster analysis. The sampling methodology was according to the GEMAS project. The results show that increasing content of chromium, cobalt and nickel detected in studied soils can be explained by a distribution pattern and the presence of ultramafic and mafic parent rocks, as well as by significant anthropogenic pollution, mainly originating from the industry at some localities. The statistically significant difference between the content of Cr and Ni in soils of Srem and C. Banat is observed. The content of the studied elements is higher in soils of Srem. The normalization to Al indicating a presence of the anthropogenic sources which my significantly affect the content of Cr and Ni in the soils from Beocin, Ruma and Stara Pazova. There is no shown influence of eventual agrochemicals application on the Cr, Ni and Co content.

Synthesis, cytotoxic activity and DNA interaction studies of new dinuclear platinum(ii) complexes with an aromatic 1,5-naphthyridine bridging ligand: DNA binding mode of polynuclear platinum(ii) complexes in relation to the complex structure.

The synthesis, spectroscopic characterization, cytotoxic activity and DNA binding evaluation of seven new dinuclear platinum(ii) complexes Pt1-Pt7, with the general formula [{Pt(L)Cl}2(µ-1,5-nphe)](ClO4)2 (1,5-nphe is 1,5-naphthyridine; while L is two ammines (Pt1) or one bidentate coordinated diamine: ethylenediamine (Pt2), (±)-1,2-propylenediamine (Pt3), trans-(±)-1,2-diaminocyclohexane (Pt4), 1,3-propylenediamine (Pt5), 2,2-dimethyl-1,3-propylenediamine (Pt6), and 1,3-pentanediamine (Pt7)), were reported. In vitro cytotoxic activity of these complexes was evaluated against three tumor cell lines, murine colon carcinoma (CT26), murine mammary carcinoma (4T1) and murine lung cancer (LLC1) and two normal cell lines, murine mesenchymal stem cells (MSC) and human fibroblast (MRC-5) cells. The results of the MTT assay indicate that all investigated complexes have almost no cytotoxic effects on 4T1 and very low cytotoxicity toward LLC1 cell lines. In contrast to the effects on LLC1 and 4T1 cells, complexes Pt1 and Pt2 had significant cytotoxic activity toward CT26 cells. Complex Pt1 had a much lower IC50 value for activity on CT26 cells compared with cisplatin. In comparison with cisplatin, all dinuclear Pt1-Pt7 complexes showed lower cytotoxicity toward normal MSC and MRC-5 cells. In order to measure the amount of platinum(ii) complexes taken up by the cells, we quantified the cellular platinum content using inductively coupled plasma mass spectrometry (ICP-QMS). Molecular docking studies performed to evaluate the potential binding mode of dinuclear platinum(ii) complexes Pt1-Pt7 and their aqua derivatives W1-W7, respectively, at the double stranded DNA showed that groove spanning and backbone tracking are the most stable binding modes.