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Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide variety of tumours. Nevertheless, the acquisition of platinum resistance is utterly common, ultimately cornering conventional platinum drugs to only palliative in many patients. Thus, encountering alternatives that are both effective and non-cross-resistant is urgent. In this work, we report the synthesis, reduction studies and luminescent properties of a series of cyclometallated (C,N,N') PtIV compounds derived from amine-imine ligands, and their remarkable efficacy at the high nanomolar range and complete lack of cross-resistance, as an intrinsic property of the platinacycle, against multiplatinum-resistant colorectal cancer (CRC) and castration-resistant prostate cancer (CRPC) metastatic cell lines generated for this work. We have also determined that the compounds are effective and selective for a broader cancer panel, including breast and lung cancer. Additionally, selected compounds have been further evaluated, finding a shift in their antiproliferative mechanism towards more cytotoxic and less cytostatic than cisplatin against cancer cells, being also able to oxidize cysteine residues and inhibit topoisomerase II, thereby holding great promise as future improved alternatives to conventional platinum drugs.

Synthesis of binuclear Cu(II) terminally closed [2+2]‐ double‐stranded helicate‐like macrocycles 1, 1′,1″, 2, 2′, 2″ and 2+4‐μ4‐oxo tetranuclear open frame complexes 3, 3′, 3″, 4, 4′, 4″ are established. Adapting one‐pot self‐assembly technique from simple three components systems: 1,1′‐binaphthyl‐2,2′‐diamine, 4‐methyl‐2,6‐diformyl phenol and cupric salts, the helicate‐like [2+2]‐ macrocyclic complexes 1–1″, 2–2″ and 2+4‐μ4‐oxo tetranuclear complexes 3–3″, 4–4″ were obtained by appropriately altering the reaction condition such as temperature and subcomponent ratio. Density Functional Theory (DFT) calculations were carried out for understanding the structural geometries, intermediates involved in the diverse formation of [2+2] and 2+4 frameworks. The single crystal X‐ray structures obtained for 1′, 2 and 3 confirms the self‐assembly process in line with DFT. This detailed analysis tempted us to derive a plausible mechanism for this long standing challenge in the synthesis of such macrocycles using 1,1′‐binaphthyl‐2,2′‐diamine (BNDA) and aromatic aldehyde. The chiroptical properties of enantiopure complexes and their catalytic applications in asymmetric oxidative coupling of 2‐naphthol to chiral 1,1’‐Bi‐2‐naphthol (BINOL) achieved in good yield and ee were discussed. peerReviewed

The biological, medicinal and diagnostic application of ferrocene derivatives is well-known [1] and the design of small ferrocene-containing molecules with potential to be synthons for complex molecules is of great importance. Since ferrocene alcohols were described as potential antineoplastic agents [2], here we report the synthesis of two novel type of disubstituted alcohols 1 and 2. The solid-state properties of compounds 1 and 2 are explored with X-ray study and corroborated with DFT calculations. The prepared alcohols 1 and 2 will be used for preparation of depsipetides as the novel type of ferrocene-peptidomimetics.

Sediment samples were collected in May 1995 from 16 locations in Kola Bay, North-west Russia, during an expedition starting from Murmansk and ending at Kildin Island in the Barents Sea. The purpose was to study the contamination level in an area with several potential sources of civilian and military radioactive pollution. 137 Cs concentrations in the sediments, algae and benthic samples were low, but small particles containing 137 Cs were separated from the sediment samples. All the sediments between the nuclear icebreaker base Atomflot and the open Barents Sea contained 60 Co. Traces of 125 Sb, 134 Cs, 95 Zr, 154 Eu and 152 Eu were also detected in some of the samples. Plutonium levels were low, but the increased 238 Pu/ 239,240 Pu ratio at Atomflot indicated a fresh release from the facility or from the waste storage vessels, Lepse and Imandra, lying in front of it. An increased 238 Pu/ 239,240 Pu ratio was also found in sediment collected in the outlet of Kola Bay in the Barents Sea.

An international research team examines field data on the distribution of manmade radionuclides in the ecosystems of the Arctic shelf, archipelagos, and coastline of the Barents‐Kara Sea region. This paper presents the results of their determinations and surveys the published literature on radionuclides in the environment and atmosphere, sea water, shelf bottom deposits, and biota of the Western Arctic.

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International audience

The possibility of modifying resorcinarenes [1] either via nucleophilic aromatic substitutions at the position 2 on the aromatic ring or the phenol hydroxyl groups increases their potential for forming multifunctional compounds. Mannich [2] condensation is the most common and arguably the most important synthetic procedure in functionalizing resorcinarenes at the aromatic ring. Mannich condensation has been employed to connect pair of adjacent [3] and opposite [4] oxazine rings on resorcinarenes by aliphatic arms forming single and double handed baskets. Flexible ethylene diamine moieties have been used to connect two resorcinarenes in a 15% yield [5]. Openining of the oxazine ring by strong mineral acid (HX) results in the corresponding N-alkylammonium halide salts [6], which maintain the parent tetrabenzoxazine cone conformation. The anion exchange of the halide counter anions by silver picrate or silver triflate leads to the exchange of the halide to the corresponding picrate and triflate (Scheme 1). The X-Ray structures of the picrate (Fig. 1) and triflate shows more distorted cone conformations when compared to the corresponding chloride or bromide salts. In the case of triflate the anion exchage was not perfect and resulted in a 3:1 triflate:chloride salt.

The situation resulting from the Chernobyl fallout in 1987 was compared to that in 2000–2001 in Finland and NW Russia and that in 2003 in the Baltic countries. 786 humus (0–3 cm layer) samples were collected during 2000–2001 in the Barents Ecogeochemistry Project, and 177 samples in the Baltic countries in 2003. Nuclides emitting γ-radiation in the 0–3 cm humus layer were measured by the Radiation and Nuclear Safety Authority–STUK in Finland. In 1987 the project area was classified by the European Commission into four different fallout classes. 137Cs inventory Bg/m2 levels measured in 2000–2003 were compared to the EU's class ranges. Fitting over the whole project area was implemented by generalizing the results for samples from the Baltic countries, for which Bq/m2 inventories could be calculated. A rough estimation was made by comparing the mass of organic matter and humus with 137Cs concentrations in these two areas. Changes in 137Cs concentration levels are illustrated in both thematic maps and tables. Radionuclide 137Cs concentrations (Bq/kg d.w.) were detected in the humus layer at all the 988 sampling sites. 134Cs was still present in 198 sites 15 years after the nuclear accident in Chernobyl. No other anthropogenic nuclides emitting γ-radiation were detected, but low levels of 60Co, 125Sb and 154Eu isotopes were found in 14 sites. Fifteen years after the Chernobyl accident, the radioactive nuclide 137Cs was and still is the most significant fallout radionuclide in the environment and in food chains. The results show that the fallout can still be detected in the uppermost humus layer in North East Europe.

A soluble complex of Zn(II) with 1-hydroxy-3-hydroxy-2-hydroxymethyl-2-(5'-formyl-salicylidimino) propane resulting in a distorted octahedral ZnN2O4 core has been synthesized and characterized by analytical and spectral methods and the structure has been established by single crystal XRD.