Construction of crystal structures of metal(II)-benzoates (M = Mn, Ni, Co, Cu, Zn, and Cd) and 1,2-bis(4-pyridyl)ethane: Effects of metal coordination modes and their catalytic activities

Five polymeric metal(II)-benzoate complexes of formula [Mn(O₂CPh)₂(CH₃OH)₂(bpa)]_n (1-Mn), [Co(O₂CPh)₂(H₂O)(bpa)_1.5]_n (2-Co), [Ni(O₂CPh)₂(H₂O)(bpa)_1.5]_n (3-Ni), [Cu(O₂CPh)₂(CH₃OH)₂(bpa)]_n (4-Cu), and [Cd(O₂CPh)₂(bpa)_1.5]_n (6-Cd) have been synthesized and characterized (bpa = 1,2-bis(4-pyridyl)ethane). They showed two kinds of structures: parallelogram-like two-dimensional sheets for Co, Ni, and Cd, and one-dimensional chains for Mn, Cu, and Zn. Since similar structures provide similar coordination geometries, the structures depend on the coordination geometries of metal ions. The compounds 1-Mn, 2-Co, 4-Cu, 5-Zn, and 6-Cd have catalyzed efficiently the transesterification of a variety of esters, while 3-Ni has displayed a very slow conversion. The reactivity of catalyst 6-Cd containing Cd ion, well known as an inert metal ion for the ligand substitution, was found to be comparable to that of 5-Zn. The reactivities of the compounds used in this study are in the order of 5-Zn > 6-Cd > 1-Mn > 4-Cu > 2-Co ? 3-Ni, indicating that the non-redox metal-containing compounds (5-Zn and 6-Cd) show better activity than the redox-active metal-containing compounds (1-Mn, 4-Cu, 2-Co, and 3-Ni).     

New species of Telenominae (Hymenoptera,Scelionidae) from the palaearctic fauna

Four new species of Telenominae of the genera Telenomus and Platytelenomus, collected in the territory of the Ukraine, Hungary, and Japan, were described: Telenomus (T.) bicolorus Kononova, T. (T.) ardens Kononova, (T.) michaylovi Kononova, and Platytelenomus mirabilis Kononova. Brief morphological characteristics of the genera Telenomus and Platytelenomus are given, and some notes concerning biology and geographical distribution of the species are presented. Telenomus (T.) bicolorus differs from all the known species of the genus Telenomus in the two-colored body: head and thorax yellow with brownish tint ventrally, mesothorax and abdomen black. The main distinguishing feature of T. (T.) ardens is its smooth shining body, T. (T.) michaylovi is similar to T. (T.) rudis Kozlov. These species can be distinguished by the structure of their antenna. The second to fourth segments of the antennal clava are transverse in T. (T.) michaylovi and are as long as wide in T. (T.) rudis. In addition, the abdominal stem and abdominal tergite II are smooth and shining, while the abdominal stem in T. (T.) rudis is striate along the entire length, and tergite II is finely striate along half of its length. Platytelenomus mirabilis is closely related to P. danubialis Szelényi, but differs in the strongly flattened body, sculpture of the abdominal stem and tergite II, and coloration of the legs. The thorax of P. mirabilis is 4–5 times as wide as high, the abdominal stem is striate along the entire length, tergite II is striate at the base, and the legs, including coxae, are yellow. The thorax of P. danubialis is 4 times as wide as high, the abdominal stem and tergite II are smooth and shining, and the legs are brown.     

Contribution of olfactory and gustatory sensations of octanoic acid in the oviposition behavior of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> (Diptera: Drosophilidae)

Selection of oviposition sites in insects represents an important part of their ecological adaptation. In Drosophila fruit flies, adult preference for a particular oviposition site determines larval food, affecting fitness throughout the entire life cycle. Two odorant-binding proteins (OBPs) OBP57d and OBP57e were identified to be involved in the evolution of specific preference for the toxic plant Morinda citrifolia L. in D. sechellia Tsacas &; Bächli. D. melanogaster Meigen mutants for Obp57d and Obp57e showed enhanced preference for octanoic acid, but still not as much as D. sechellia does, indicating that other genes are also involved in the behavioral evolution of D. sechellia. Here, by using an improved method for behavioral assay, we found that the ablation of antenna enhanced the preference for octanoic acid in the Obp57d and Obp57e mutants to a level comparable with D. sechellia, suggesting that both olfactory and gustatory sensations are involved in oviposition site selection in response to octanoic acid. Behavioral analysis of gene-knockout strains revealed that Odorant receptor co-receptor (Orco) has little contribution compared with the effect of antennal ablation. These data suggest that in addition to Obp57d and Obp57e, the evolution of D. sechellia involves genetic changes in olfactory genes that function independently from Orco.     

Gene expression profiles in liver of pigs with extreme high and low levels of androstenone

Background

Boar taint is the unpleasant odour and flavour of the meat of uncastrated male pigs that is primarily caused by high levels of androstenone and skatole in adipose tissue. Androstenone is a steroid and its levels are mainly genetically determined. Studies on androstenone metabolism have, however, focused on a limited number of genes. Identification of additional genes influencing levels of androstenone may facilitate implementation of marker assisted breeding practices. In this study, microarrays were used to identify differentially expressed genes and pathways related to androstenone metabolism in the liver from boars with extreme levels of androstenone in adipose tissue.

Results

Liver tissue samples from 58 boars of the two breeds Duroc and Norwegian Landrace, 29 with extreme high and 29 with extreme low levels of androstenone, were selected from more than 2500 individuals. The samples were hybridised to porcine cDNA microarrays and the 1% most significant differentially expressed genes were considered significant. Among the differentially expressed genes were metabolic phase I related genes belonging to the cytochrome P450 family and the flavin-containing monooxygenase FMO1. Additionally, phase II conjugation genes including UDP-glucuronosyltransferases UGT1A5, UGT2A1 and UGT2B15, sulfotransferase STE, N-acetyltransferase NAT12 and glutathione S-transferase were identified. Phase I and phase II metabolic reactions increase the water solubility of steroids and play a key role in their elimination. Differential expression was also found for genes encoding 17beta-hydroxysteroid dehydrogenases (HSD17B2, HSD17B4, HSD17B11 and HSD17B13) and plasma proteins alpha-1-acid glycoprotein (AGP) and orosomucoid (ORM1). 17beta-hydroxysteroid dehydrogenases and plasma proteins regulate the availability of steroids by controlling the amount of active steroids accessible to receptors and available for metabolism. Differences in the expression of FMO1, NAT12, HSD17B2 and HSD17B13 were verified by quantitative real competitive PCR.

Conclusion

A number of genes and pathways related to metabolism of androstenone in liver were identified, including new candidate genes involved in phase I oxidation metabolism, phase II conjugation metabolism, and regulation of steroid availability. The study is a first step towards a deeper understanding of enzymes and regulators involved in pathways of androstenone metabolism and may ultimately lead to the discovery of markers to reduce boar taint.

     

The structural basis for the difference in absorbance spectra for the FMO antenna protein from various green sulfur bacteria

The absorbance spectrum of the Fenna-Matthews-Olson protein—a component of the antenna system of Green Sulfur Bacteria—is always one of two types, depending on the species of the source organism. The FMO from Prosthecochloris aestuarii 2K has a spectrum of type 1 while that from Chlorobaculum tepidum is of type 2. The previously reported crystal structures for these two proteins did not disclose any rationale that would explain their spectral differences. We have collected a 1.3 Å X-ray diffraction dataset of the FMO from Prosthecochloris aestuarii 2K, which has allowed us to identify an additional Bacteriochlorophyll-a molecule with chemical attachments to both sides of the central magnesium atom. A new analysis of the previously published X-ray data for the Chlorobaculum tepidum FMO shows the presence of a Bacteriochlorophyll-a molecule in an equivalent location but with a chemical attachment from only one side. This difference in binding is shown to be predictive of the spectral type of the FMO.     

Physicochemical properties of multicomponent poly(hydroxyalkanoates)

The properties of new five-component poly(hydroxyalkanoates) (PHA) formed by short-and medium-chain monomers synthesized by the bacterium Wautersia eutropha B5786 were studied by X-ray diffraction, IR spectroscopy, differential thermal analysis, and viscometry. The degree of crystallinity of PHA decreased from 72 to 57% as the molar fraction of hydroxyhexanoate increased from 2.5 to 18.0 mol%. The melting temperature (T _m) and decomposition temperature (T _d) of the multicomponent PHA are lower than those for poly(hydroxybutyrate), whose T _m and T _d are 168–170 and 260–265°C, respectively. Both parameters of the multicomponent PHA decrease to 156 and 252°C, respectively, as the hydroxyhexanoate mole fraction is raised. The effect of hydroxyhexanoate on the physicochemical properties of the PHA is similar to that of hydroxyvalerate observed previously.     

Comparative ecology of Ostracoda (Crustacea) in two rheocrene springs (Bolu,Turkey)

A total of ten taxa belonging to the class Ostracoda of the Crustacea (Darwinula stevensoni, Candona neglecta, Cypria ophthalmica, Ilyocypris bradyi, Prionocypris zenkeri, Herpetocypris chevreuxi, Psychrodromus olivaceus, Heterocypris incongruens, Scottia pseudobrowniana, Eucypris sp.) were collected from two rheocrene Darwinula stevensoni springs (Çetin Bey and Çaygökp?nar springs) on 15 separate occasions between November 2002 and November 2004. Almost all of the species identified exhibit cosmopolitan distributions – at least in the Holarctic region. The presence of Scottia pseudobrowniana represents the second recording of this species in the ostracod fauna of Turkey. The dominant taxa in both springs was Cy. ophthalmica, I. bradyi, Pr. zenkeri and Ca. neglecta. Correlation analyses suggested a significant positive relationship in relative abundance between I. bradyi, Pr. zenkeri and Cy. ophthalmica. Species composition differed significantly between the upper and lower study sites for each spring, but differences could not be detected between sites at the same elevation across sites. Environmental tolerance index (ETI) values suggest that species with high optima and tolerance ranges show cosmopolitan characteristics.     

Structure,electronic properties,and NBO and TD-DFT analyses of nickel(II), zinc(II), and palladium(II) complexes based on Schiff-base ligands

In this work we studied the structural and electronic properties of the metal–Schiff base complexes Ni\( {\mathrm{L}}_2^2 \) (1), Pd\( {\mathrm{L}}_2^1 \) (2), Zn\( {\mathrm{L}}_2^2 \) (3), and Ni\( {\mathrm{L}}_2^1 \)(4), where L¹ and L² are Schiff bases synthesized from salicylaldehyde and 2-hydroxy-5-methylbenzaldehyde, respectively. Natural bond analysis showed that in complexes 1 and 2, the metal ion coordinates to the ligands through electron donation from lone pairs on ligand nitrogen and oxygen atoms to s and d orbitals on the metal ion. In complex 3, metal–N and metal–O bonds are formed through charge transfer from the lone pairs on nitrogen and oxygen atoms to an s orbital of Zn. Dimethylation of the phenolate rings in the ligands decreases the energy gap and redshifts the spectrum of the nickel complex. The main absorptions observed were assigned on the basis of singlet-state transitions. The simulated spectra of the two complexes 1 and 2 are characterized by excited states with ligand-to-ligand charge-transfer (LLCT), metal-to-ligand charge-transfer (MLCT), ligand-to-metal charge-transfer (LMCT), and metal-centered (MC) character.

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Graphical abstract Geometric structure of the palladium complex.

     

Descriptions of two new species of feather mites (Acarina: Psoroptidia: Pteronyssidae) from Ivory Coast

Two new feather mite species of the family Pteronyssidae Oudemans, 1941 collected from birds captured in Ivory Coast are described: Pteronyssoides cyanomitrae n. sp. from Cyanomitra obscura (Jardine) (Passeriformes: Nectariniidae) and Conomerus pygmaeus n. sp. from Hylia prasina (Cassin) (Passeriformes: Macrosphenidae). Pteronyssoides cyanomitrae n. sp. belongs to the nectariniae species group and differs from the closest species, P. garioui Gaud & Mouchet, 1959, in having, in males, the adanal shield present and setae f longer than setae d on the tarsus III; females of this species have the hysteronotal shield with two small median incisions on the anterior margin barely extending beyond the level of setae e2. Conomerus pygmaeus n. sp. is the first species of this genus found on a passerine host, and seems to be more similar to C. sclerosternus Gaud, 1990. This new species has the following distinctive characters: in females, the opisthosoma has small lobe-like extensions and the central sclerite is fused posteriorly with the lateral opisthosomal sclerites; in males, coxal fields I–IV lack large sclerotised areas.     

Phylogenetic relationships of the genus <Emphasis Type="Italic">Armadolepis</Emphasis> Spassky, 1954 (Eucestoda,Hymenolepididae), with descriptions of two new species from Palaearctic dormice (Rodentia,Gliridae)

Two new species of hymenolepidid cestodes belonging to the genus Armadolepis Spassky, 1954 are described from dormice (Gliridae) from the southern East European Plain and the northwestern Caucasus, Russia. Armadolepis (Bremserilepis) longisoma n. sp., with a rudimentary, unarmed rostellar apparatus is described from the fat dormouse Glis glis (Linnaeus) from the Republic of Adygeya, Russia. Additionally, A. (Armadolepis) dryomi n. sp., characterised by a well-developed rostellar apparatus and armed rhynchus is described from the forest dormouse Dryomys nitedula Pallas from Rostov Oblast’, Russia. Armadolepis (Bremserilepis) longisoma n. sp. differs from A. (Bremserilepis) myoxi (Rudolphi, 1819) in having a substantially longer strobila and cirrus-sac, wider scolex and ovary and larger rostellar pouch and testes. Armadolepis (Armadolepis) dryomi n. sp. is distinguishable from A. (Armadolepis) spasskii Tenora & Baru?, 1958, A. (Armadolepis) jeanbaeri Makarikov, 2017 and A. (Armadolepis) tenorai Makarikov, 2017 in having a substantially longer and wider strobila, and larger rostellar pouch and cirrus-sac. Furthermore, A. dryomi n. sp. can be distinguished from its congeners by the number and size of rostellar hooks and the arrangement of the testes. Phylogenetic affinities of Armadolepis were studied for the first time using partial sequences of the nuclear ribosomal 28S DNA gene. Phylogenetic analysis strongly supported the status of Armadolepis as a separate genus belonging to the “Rodentolepis clade”.     

Revision of Jaegeria (Compositae-Heliantheae)

The genusJaegeria consists of a diploid-polyploid complex of eight species found in moist habitats from Mexico to South America. The distributions, habitats, generic affinities, and tribal placement are discussed. Chromosome numbers were determined for all species exceptJ. axillaris, which is known only from Colombia.J. glabra andJ. pedunculata are diploid (2n = 18) ;J. hirta, J. macrocephala, J. gracilis, andJ. crassa are tetraploid (2n = 36) ;J. bellidiflora is octoploid (2n = 72). One Galápagos Island endemic,J. gracilis, is quite similar to the common mainland species,J. hirta, but the other endemic,J. crassa, is quite distinct from any other species.J. bellidijlora is most similar morphologically toJ. glabra;J. macrocephala is allied toJ. pedunculata. J. axillaris is somewhat distinct from the other species.     

Chromosomes of Ichneumonidae (Hymenoptera): New results and conclusions

New data were obtained on the karyotypes of 12 parasitic wasp species of the family Ichneumonidae: Scambus detritus (2n = 28), S. vesicarius (2n = 28), Pimpla contemplator (2n = 36), Theronia atalantae (2n = 24), Stenomacrus sp. 2 (n = 18, 2n = 36), Phygadeuon sp. 3 (2n = 32), Ichneumon memorator (2n = 24), I. vorax (2n = 22), Lymantrichneumon disparis (2n = 26), Orthopelma mediator (n = 15, 2n = 30), Lissonota buccator (2n = 22), and Trichionotus flexorius (2n = 16). Chromosomes of Anomaloninae were studied for the first time. The data on the karyotype structure of the subfamily Orthopelmatinae were revised. Various aspects of chromosome variability in Ichneumonidae are discussed.     

5-Nitroimidazole-derived Schiff bases and their copper(II) complexes exhibit potent antimicrobial activity against pathogenic anaerobic bacteria

In the present work a family of novel secnidazole-derived Schiff base compounds and their copper(II) complexes were synthesized. The antimicrobial activities of the compounds were evaluated against clinically important anaerobic bacterial strains. The compounds exhibited in vitro antibacterial activity against Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides vulgatus, Bacteroides ovatus, Parabacteroides distasonis and Fusubacterium nucleatum pathogenic anaerobic bacteria. Upon coordination to copper(II) the antibacterial activity significantly increased in several cases. Some derivatives were even more active than the antimicrobial drugs secnidazole and metronidazole. Therefore, the compounds under study are suitable for in vivo evaluation and the microorganisms should be classified as susceptible to them. Electrochemical studies on the reduction of the nitro group revealed that the compounds show comparable reduction potentials, which are in the same range of the bio-reducible drugs secnidazole and benznidazole. The nitro group reduction potential is more favorable for the copper(II) complexes than for the starting ligands. Hence, the antimicrobial activities of the compounds under study might in part be related to intracellular bio-reduction activation. Considering the increasing resistance rates of anaerobic bacteria against a wide range of antimicrobial drugs, the present work constitutes an important contribution to the development of new antibacterial drug candidates.     

Binding of Cd(II), Pb(II), and Zn(II) to a type 1 metallothionein from maize (<Emphasis Type="Italic">Zea mays</Emphasis>)

Metallothioneins (MTs) are a family of ubiquitous, low-molecular-mass, cysteine-rich proteins that play a significant role in maintaining intracellular metal homeostasis, eliminating metal toxification, and protecting cells against oxidative damages. Research activity on plant MTs, although known for 30 years, has only moderately increased in the past few years. In this study, a type 1 MT from maize (Zea mays) (ZmMT1) was successfully expressed in Escherichia coli strain BL21 (DE3). The UV absorption spectra recorded after the reconstitution of apo-ZmMT1 with different metals demonstrated that ZmMT1 can coordinate up to six Zn(II) ions, six Cd(II) ions, and even higher amounts of Pb(II). In addition, the general metal ion coordination abilities of ZmMT1 characterized by pH-dependent zinc-, lead- and cadmium-binding stability and by the competitive reaction with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) were evaluated. Results showed that the affinity of metal ions for the recombinant form of ZmMT1 can be arranged as follows: Cd(II)?>?Pb(II)?>?Zn(II). The observation revealed that chelating agents, such as ethylene diamine tetraacetic acid (EDTA) and ATP, accelerate the oxidation of ZmMT1 in the following order: EDTA???l-histidine?>?ATP?≈?citrate. Meanwhile, commonly used buffers increase the reactivity of ZmMT1 with DTNB in the following order: PBS?>?Tris–HCl?>?HEPES.     

Chlorophylls <Emphasis Type="Italic">d</Emphasis> and <Emphasis Type="Italic">f</Emphasis> and their role in primary photosynthetic processes of cyanobacteria

The finding of unique Chl d- and Chl f-containing cyanobacteria in the last decade was a discovery in the area of biology of oxygenic photosynthetic organisms. Chl b, Chl c, and Chl f are considered to be accessory pigments found in antennae systems of photosynthetic organisms. They absorb energy and transfer it to the photosynthetic reaction center (RC), but do not participate in electron transport by the photosynthetic electron transport chain. However, Chl d as well as Chl a can operate not only in the light-harvesting complex, but also in the photosynthetic RC. The long-wavelength (Q_y) Chl d and Chl f absorption band is shifted to longer wavelength (to 750 nm) compared to Chl a, which suggests the possibility for oxygenic photosynthesis in this spectral range. Such expansion of the photosynthetically active light range is important for the survival of cyanobacteria when the intensity of light not exceeding 700 nm is attenuated due to absorption by Chl a and other pigments. At the same time, energy storage efficiency in photosystem 2 for cyanobacteria containing Chl d and Chl f is not lower than that of cyanobacteria containing Chl a. Despite great interest in these unique chlorophylls, many questions related to functioning of such pigments in primary photosynthetic processes are still not elucidated. This review describes the latest advances in the field of Chl d and Chl f research and their role in primary photosynthetic processes of cyanobacteria.     

Characterization and fine mapping of <Emphasis Type="Italic">osh15</Emphasis>(<Emphasis Type="Italic">t</Emphasis>), a novel dwarf mutant gene in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Plant height is one of the most important agronomic traits of plant architecture, and also affects grain yield in rice. In this study, we obtained a novel dwarf rice mutant of japonica variety Shennong9816, designated Shennong9816d. Compared with wild-type, the Shennong9816d plant height was significantly reduced, and the tiller number significantly increased. Additionally, the mutant yield component, and the number of large and small vascular bundles were significantly decreased compared with wild-type. Genetic analysis indicated that the Shennong9816d dwarf phenotype was controlled by a recessive nuclear gene, while the plant was shown to be sensitive to gibberellic acid. Using a large F₂ population derived from a cross between Shennong9816d and the indica rice variety Habataki, the osh15(t) gene was fine mapped between RM20891 and RM20898, within a physical distance of 73.78 kb. Sequencing analysis showed that Shennong9816d carries a 1 bp mutation and a 30 bp insertion in the OSH15 region. These results suggest that osh15(t) is a novel allelic mutant originally derived from japonica variety Shennong9816, which may be useful for introducing the semi-dwarf phenotype to improve plant architecture in rice breeding practice.     

New species of scelionids (Hymenoptera,Scelionidae) of the Israel fauna

Four new species of Scelionidae of the genera Telenomus (subgenus Telenomus) and Macroteleia (Telenomus (T.) ordanus Kononova, T. (T.) lunatus Kononova, Macroteleia israiliensis Kononova, and M. simutniki Kononova) from Israel are described. T. (T.) ordanus differs from the species of the subgenus Telenomus in the presence of short rugae on abdominal tergite II, smooth and shiny abdominal stem, and yellow legs. T. (T.) lunatus, similar to T. (T.) clavatus Kozlov et Kononova, can be distinguished by the smaller size, finer body sculpture, and sculpture of abdominal tergite II. Macroteleia israiliensis differs from M. rufa Szelényi in the more slender body and its coloration, as well as in the structure of the propodeum. M. simutniki differs from M. aurea Kozlov et Kononova in the wider abdomen and in the antennal structure (the 2nd antennal segment is wider, segments of the antennal club are as long as wide).     

Anticandidal activity of hetero-dinuclear copper(II) Mn(II) Schiff base and its potential action of the mechanism

Invasive fungal infections are one of the major challenges especially for immunosuppressed patients since they are drug resistant and pathogen to patients. Therefore, developing new, efficient and nonresistant antifungal agents have been a primary focus of international research. In the current study, a novel Schiff base [hetero-dinuclear copper(II) Mn(II) complex] (SB) derivative was investigated for its anticandidal activity against Candida albicans and possible mechanisms inducing cell death. The results revealed that SB treatment induces apoptotic and necrotic pathways in C. albicans ATCC10231 strain. Intracellular reactive oxygen species production determined by 2′,7′-dichlorofluorescein diacetate staining was triggered by SB and amphotericin B administrations in a dose-dependent manner. Gene expression analysis demonstrated that SB exposure resulted in regulation of critical development and stress related gene expressions. SB treatment directly upregulated expression of stress related genes, DDR48 and RIM101, while suppressed important cell signaling and antibiotic resistance acquiring related genes such as HSP90, ERG11 and EFG1. Furthermore, CaMCA1 mRNA levels were found to be significantly high in SB-treated yeast cells, indicating possible caspase-like mechanism activation. Scanning electron microscopy analysis confirmed that SB treatment led to severe cell wall integrity disruption and wrinkling. The study will encourage development of SB-based anticandidal regimens but further studies are highly warranted to understand limitations and the extended use in the routine.