Copper(II) complexes based on a new chelating 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine ligand: Synthesis and crystal structures. Lone pair-π, C-H···π, π-π and C-H···A (A = N, Cl) non-covalent interactions

A new bidentate chelating pyrazolylpyrimidine ligand bearing a strong electron-donating substituent, i.e. 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L) (Scheme 1), has been synthesized and used to obtain the copper(II) complexes by reaction with CuCl₂. The molar ratio Cu:L = 1:2 leads to isolation of a complex having CuL₂Cl₂ empirical formula, while the molar ratio Cu:L = 1:1 gives a complex with CuLCl₂ empirical formula. The crystal structure of L as well as the structures of both complexes were studied by single crystal X-ray diffraction. The crystal structure of CuL₂Cl₂ compound is formed by trans-[CuL₂Cl₂] mononuclear molecules. Surprisingly, in contrast to the previous compound having molecular structure, the crystal structure of CuLCl₂ consists of mononuclear [CuL₂Cl]⁺ complex cations and dinuclear [Cu₂Cl₆]²⁻ anions. Thus, formula of CuLCl₂ complex can be represented as [CuL₂Cl]₂[Cu₂Cl₆]. In both complexes molecules of L adopt bidentate chelating coordination mode through N² atom of pyrazole and N³ atom of pyrimidine rings forming five-membered CuN₃C metallocycles. Owing to C-H···N interactions and π-π-stacking L molecules form 2D network. In the structure of trans-[CuL₂Cl₂] there exist double lone pair(N(piperidine))-π(pyrimidine) interactions and C-H···Cl contacts resulting in the formation of 1D chains. Layered 2D structure of [CuL₂Cl]₂[Cu₂Cl₆] results from C-H···Cl, C-H···π and double lone pair(Cl([CuL₂Cl]⁺ complex cation)-π(pyrimidine) interactions.     

Surface Topography and Cytomatrix Elements in Protoplasts from Plant Cells

We studied the surface topography of protoplasts from callus of Daucus sativus(Hofm.) Roehl. and from mesophyll cells of Nicotiana tabacumL. We also followed the distribution of actin elements of the cytomatrix in the subcortical cytoplasm layer. Protoplasts were prepared for scanning electron microscopy by a modified method without drying in the critical point apparatus. After postfixation with OsO₄, carrot and tobacco protoplasts had a similar topography of the surface: it was rough and had few pores. When carrot protoplasts were not postfixed with OsO₄, their surface looked different: it was folded and had 1.5-m pores, which sometimes were bordered with globules 0.3 m in diameter, or it consisted of conical cells varying in depth and size of their bases. We believe that, when protoplasts were not fixed with OsO₄, they lost lipid-containing structures from their surface, and what remained was the protein carcass of the plasmalemma and the underlying layer of the cytoplasm. The inner surface of opened carrot protoplasts had elaborate topography, apparently produced by the elements of the cytomatrix, that is, a relatively thick layer of the cortical cytoplasm, where, using phalloidin–colloidal gold and transmission electron microscopy, we could observe a dense network of actin filaments.     

Characteristics of opisthorchiasis foci in southern West Siberia

Natural foci of opistorchiasis were studied in southern West Siberia. It has been shown that the foci are of two biocenotic groups: floodplain-river and lake-interfluve. The main difference between them is that in the former intermediate hosts of opistorchides are commercial Cyprinidae fish and final hosts are humans and domestic carnivores, whereas in the latter, intermediate hosts are noncommercial Cyprinidae fish, wild carnivores, and muskrat. Floodplain-river foci are associated with river basins in the north of Baraba, big and small tributaries of the Ob and Irtysh rivers, as well as euthrophic lakes within floodplains of the rivers. Lake-interfluve foci are associated with euthrophic and dystrophic lakes in the river floodplains which do not communicate with the Ob-Irtysh water system. They are located in North Kulunda and in the south of Baraba lowland.     

Helminthiasis, metabolic rates and cold resistance in the red-backed vole from a natural population

Estimation of the standard metabolic rate (SMR), maximal oxygen consumption (MOC) and thermoregulation ability in males of red-backed vole (Clethrionomys rutilus Pallas, 1779) have shown that individuals infected with nematodes Heligmosomum mixtum, regardless of intensity of worm infection, had an increased level of oxygen consumption in the cold exposition, while the individuals infected with the cestodes Arostrilepis horrida, had a lover oxygen consumption than non-invaded individuals. Worm burden of A. horrida correlated negatively with MOC value in the hosts. Thermo-conductance of individuals infected with A. horrida was significantly lower than in ones infected with H. mixtum. Opposite effects of these two helminthes seems to be determined by the specificity of pathogenesis and different body mass of parasites. Total body mass of nematodes are usually less than 0.2% of the host body mass whereas the total body mass of cestodes may exceed 5% of the host body mass.     

Influence of the phase of the number and demographic structure of the water vole population on its infection by helminthes

In this work we have analyzed results of the long-term investigations of the helminthes distribution in the various demography groups of the water vole population (Arvicola terrestris L.) in North Baraba (Novosibirsk region). The data on the dominant parasites of these rodents: trematodes Notocotylus noyeri (Joyeux, 1922), cestodes Limnolepis transfuga Spassky et Merkuscheva, 1967, nematodes Capillaria wioletti Ruchljadeva, 1950, Longistriata minuta (Dujarden, 1845) and Heligmosomum costellatum (Dujarden, 1845) have shown that the number of parasites in biocenosis are connected with different factors, such as the demographic structure of the host population, the alternation of hosts number and conditions of the environment (dry and damp phases of the climatic cycle). In the dry phase the main parasitize load N. noyeri, L. transfuga and C. wioletti connects with the breeding group; in the damp period - with immature rodents. Independently of the phase climatic cycle and the density of the water vole population the great bulk of nematodes L. minuta and H. costellatum was uncovered of the immature individuals. In any case the number of helminthes changed synchronously with such of the its host.     

Effects of Metarhizium robertsii on the bloodsucking mosquito Aedes flavescens and non‐target predatory insects (Odonata)

The effects of different concentrations and methods of treatment with Metarhizium robertsii Bisch., Rehner & Humber conidia on the non‐target aquatic dragonfly larvae Lestes sponsa Hansemann, Lestes dryas Kirby and Aeshna affinis Vander Linden and on the target bloodsucking mosquito larvae Aedes (O.) flavescens (Muller) were analysed. We found that dragonflies are significantly less susceptible than mosquitoes to the fungus. Larvae of L. sponsa larvae were more susceptible to wet conidia than dry conidia. However, the mortality of the air‐breathing larvae of A. affinis was significantly higher after treatment with dry conidia relative to aqueous suspension. The results help to minimize the negative effects of entomopathogenic fungi on non‐target predator insects under the control of mosquito larvae.     

Helminthes of the water vole <Emphasis Type="Italic">Arvicola terrestris</Emphasis> Linnaeus of forest-bog biocenoses in the north of the Baraba Lowland

The results of helminthological studies of the wintered water voles are given. This group of voles hosts 13 species of helminthes: 1, Trematoda, 7, Cestoda, and 5, Nematoda. The trematode Notocotilus noyeri Joyex, 1922 (88 ±2.7)% and the cestode Arvicolepis transfuga (Spassky et Merkusheva, 1967) (68.9 ± 3.8)% dominate among them in the extensiveness of invasion (EI). The factors are studied that determine the probability of the water voles being infected with the background species of helminthes. A relation of the long-term dynamics of the host population with the dynamics of the infection with the dominant species of the parasites is established.     

Zinc(II) and cadmium(II) complexes based on 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L): Synthesis, structure, luminescence. Double lone pair-π interactions in the structure of ZnL2Cl2

A series of zinc(II) and cadmium(II) complexes with 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L), ZnLCl₂, CdLCl₂, ZnL₂Cl₂, CdL₂Cl₂, CdL₂Cl₂·0.5Me₂CO·1.5H₂O and CdL₂Cl₂·0.5CHCl₃·0.5H₂O, have been synthesized. The compounds ZnLCl₂ and CdLCl₂ were obtained in a M:L = 1:1 molar ratio in EtOH solutions, while ZnL₂Cl₂ and CdL₂Cl₂ were isolated in a M:L = 1:3 molar ratio in EtOH/Me₂CO mixtures. Surprisingly, attempts to crystallize CdLCl₂ from EtOH/Me₂CO mixture afforded single crystals of a compound, having 1:2 metal-to-ligand stoichiometry, CdL₂Cl₂·0.5Me₂CO·1.5H₂O, instead of a complex with 1:1 stoichiometry. At the same time, crystallization of CdL₂Cl₂ from Me₂CO/CHCl₃ mixture afforded CdL₂Cl₂·0.5CHCl₃·0.5H₂O single crystals. According to X-ray crystal structure data, ZnLCl₂, ZnL₂Cl₂, CdL₂Cl₂·0.5Me₂CO·1.5H₂O and CdL₂Cl₂·0.5CHCl₃·0.5H₂O complexes have molecular mononuclear structures. The molecules of L adopt bidentate chelating binding mode being coordinated to the metal ions through N² atom of the pyrazole and N³ atom of the pyrimidine rings. The coordination core of zinc atom in ZnLCl₂ complex is a distorted ZnN₂Cl₂ tetrahedron. The coordination cores of metal atoms in the structures of ZnL₂Cl₂, CdL₂Cl₂·0.5Me₂CO·1.5H₂O and CdL₂Cl₂·0.5CHCl₃·0.5H₂O are the distorted cis-MN₄Cl₂ (M = Zn, Cd) octahedra. In the structure of ZnL₂Cl₂ double lone pair(N(piperidine))-π(pyrimidine) interactions were observed. The photoluminescent properties of L, ZnLCl₂, CdLCl₂, ZnL₂Cl₂ and CdL₂Cl₂ were studied in the solid state under the same experimental conditions. These compounds were found to display bright blue luminescence. Highest relative intensity of emission was detected for ZnL₂Cl₂.     

New data on the distribution of hantavirus in rodent populations in Siberia

New foci of hantavirus infection were found in Altai and Krasnoyarsk krais, in Novosibirsk, Kemerovo, and Tomsk oblasts, and Altai Republic. It is shown that hantaviruses are distributed in all landscape zones and subzones. The bank vole, the gray red-backed vole, the northern red-backed vole, the narrow-headed vole, the field vole, the root vole, the steppe lemming, and the Korean field and striped mice.