A three-dimensional gadolinium organic framework based on a pyridinedicarboxylic acid organic linker with a paddle-wheel-type network structure.

A new gadolinium(III)-pyridine-2,5-dicarboxylic acid (GdIII-2,5-H2pdc)-based three-dimensional coordination polymer, namely, poly[dimethylazanium [bis(µ-pyridine-2,5-dicarboxylato)gadolinium(III)]], {[(CH3)2NH2][Gd(C7H3NO4)2]}n, CP-1, has been synthesized via a typical solvothermal method. The as-synthesized material was characterized in the solid state using single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and FT-IR spectroscopy. During the synthesis of CP-1, the in situ dimethylformamide (DMF) promotes the formation of a dimeric unit and these act as secondary building blocks in the assembly of a three-dimensional anionic {[Gd(pdc)2]-}∞ framework. The framework has channels along the c axis which are filled by dimethylazanium cations. Interestingly, the framework shows a helical-type assembly running down the a axis. A Hirshfeld surface analysis of CP-1 suggests that extra stability is provided by hydrogen-bonding interactions. The magnetic properties of CP-1 showed weak antiferromagnetic couplings between adjacent Gd3+ ions.

Noviherbaspirillum aridicola sp. nov., isolated from an arid soil in Pakistan.

Strain NCCP-691T was isolated from a soil sample collected from an arid soil in Karak, Khyber Pakhtunkhwa, Pakistan. Phenotypically, the cells were Gram-stain-negative, aerobic and motile rods. The organism was able to grow between 20-40 °C (optimum at 30-37 °C), at pH 5.5-8.0 (optimum at pH 7.0-7.2) and tolerated 0-1.5% NaCl (w/v) (optimum at 0-0.5). Based on 16S rRNA gene sequences, strain NCCP-691T formed a distinct phylogenetic clade with Noviherbaspirillum arenae, N. agri, N. denitrificans and N. autotrophicum (having sequence similarities of 99.0; 98.1; 98.0 and 97.7% respectively). Phylogenetic analyses based on the whole genome sequences confirmed that strain NCCP-691T should be affiliated to the genus Noviherbaspirillum. The average nucleotide identity values compared to other species of Noviherbaspirillum were below 95-96 % and digital DNA-DNA hybridization values were less than 70 %. Chemotaxonomic analyses showed that the strain had ubiquinone-8, as the only respiratory quinine. The major cellular fatty acids were summed feature 3 (C16 : 1 ω 7 c/C16 : 1 ω 6 c, 35.9 %), summed feature 8 (C18 : 1 ω 7 c/C18 : 1 ω 6 c, 26.9 %) and C16 : 0 (22.9 %) and the polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The genomic DNA G+C content was 65.5 mol% (from draft genome). Genome analyses showed that strain NCCP-691T had terpene and arylpolyene biosynthetic genes clusters and genes related to resistance against heavy metals. Based on phylogenetic analyses, phenotypic features and genomic comparison, it is proposed that strain NCCP-691T is a novel species of the genus Noviherbaspirillum and the name Noviherbaspirillum aridicola sp. nov. is proposed. Type strain is NCCP-691T (=KCTC 52721T=CGMCC 1.13600T).

Virtual screening of quinoline derived library for SARS-COV-2 targeting viral entry and replication.

The COVID-19 pandemic infection has claimed many lives and added to the social, economic, and psychological distress. The contagious disease has quickly spread to almost 218 countries and territories following the regional outbreak in China. As the number of infected populations increases exponentially, there is a pressing demand for anti-COVID drugs and vaccines. Virtual screening provides possible leads while extensively cutting down the time and resources required for ab-initio drug design. We report structure-based virtual screening of a hundred plus library of quinoline drugs with established antiviral, antimalarial, antibiotic or kinase inhibitor activity. In this study, targets having a role in viral entry, viral assembly, and viral replication have been selected. The targets include: 1) RBD of receptor-binding domain spike protein S 2) Mpro Chymotrypsin main protease 3) Ppro Papain protease 4) RNA binding domain of Nucleocapsid Protein, and 5) RNA Dependent RNA polymerase from SARS-COV-2. An in-depth analysis of the interactions and G-score compared to the controls like hydroxyquinoline and remdesivir has been presented. The salient results are (1) higher scoring of antivirals as potential drugs (2) potential of afatinib by scoring as better inhibitor, and (3) biological explanation of the potency of afatinib. Further MD simulations and MM-PBSA calculations showed that afatinib works best to interfere with the the activity of RNA dependent RNA polymerase of SARS-COV-2, thereby inhibiting replication process of single stranded RNA virus. Communicated by Ramaswamy H. Sarma.

5-HT1A targeting PARCEST agent DO3AM-MPP with potential for receptor imaging: Synthesis, physico-chemical and MR studies.

Contrast enhancement in MRI using magnetization or saturation transfer techniques promises better sensitivity, and faster acquisition compared to T1 or T2 contrast. This work reports the synthesis and evaluation of 5-HT1A targeted PARACEST MRI contrast agent using 1,4,7,10-tetraazacycloDOdecane-4,7,10-triacetAMide (DO3AM) as the bifunctional chelator, and 5-HT1A-antagonist methoxyphenyl piperazine (MPP) as a targeting unit. The multi-step synthesis led to the MPP conjugated DO3AM with 60% yield. CEST-related physicochemical parameters were evaluated after loading DO3AM-MPP with paramagnetic MRI active lanthanides: Gadolinium (Gd-DO3AM-MPP) and Europium (Eu-DO3AM-MPP). Luminescence lifetime measurements with Eu-DO3AM-MPP and computational DFT studies using Gd-DO3AM-MPP revealed the coordination of one water molecule (q = 1.43) with metal-water distance (rM-H2O) of 2.7 Å and water residence time (τm) of 0.23 ms. The dissociation constant of Kd 62 ± 0.02 pM as evaluated from fluorescence quenching of 5-HT1A (protein) and docking score of -4.81 in theoretical evaluation reflect the binding potential of the complex Gd-DO3AM-MPP with the receptor 5-HT1A. Insights of the docked pose reflect the importance of NH2 (amide) and aromatic ring in Gd-DO3AM-MPP while interacting with Ser 374 and Phe 370 in the antagonist binding pocket of 5-HT1A. Gd-DO3AM-MPP shows longitudinal relaxivity 5.85 mM-1s-1 with a water residence lifetime of 0.93 ms in hippocampal homogenate containing 5-HT1A. The potentiometric titration of DO3AM-MPP showed strong selectivity for Gd3+ over physiological metal ions such as Zn2+ and Cu2+. The in vitro and in vivo studies confirmed the minimal cytotoxicity and presential binding of Gd-DO3AM-MPP with 5-HT1A receptor in the hippocampus region of the mice. Summarizing, the complex Gd-DO3AM-MPP can have a potential for CEST imaging of 5-HT1A receptors.

In silico Potential of Approved Antimalarial Drugs for Repurposing Against COVID-19.

Although the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is wreaking havoc and resulting in mortality and morbidity across the planet, novel treatments are urgently needed. Drug repurposing offers an innovative approach in this context. We report here new findings on the in silico potential of several antimalarial drugs for repurposing against COVID-19. We conducted analyses by docking the compounds against two SARS-CoV-2-specific targets: (1) the receptor binding domain spike protein and (2) the main protease of the virus (MPro) using the Schrödinger software. Importantly, the docking analysis revealed that doxycycline (DOX) showed the most effective binding to the spike protein of SARS-CoV-2, whereas halofantrine and mefloquine bound effectively with the main protease among the antimalarial drugs evaluated in the present study. The in silico approach reported here suggested that DOX could potentially be a good candidate for repurposing for COVID-19. In contrast, to decipher the actual potential of DOX and halofantrine against COVID-19, further in vitro and in vivo studies are called for. Drug repurposing warrants consideration as a viable research and innovation avenue as planetary health efforts to fight the COVID-19 continue.

Feasible regeneration and agro bacterium-mediated transformation of Brassica juncea with Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene.

In the present study an effort has been made to optimize the in vitro regeneration protocol for Agrobacterium-mediated transformation of Brassica juncea, because of its importance as oilseed crops. The highest callus induction frequency of 87% was observed on MS (Murashige and Skoog, 1962) medium supplemented with 4 µM 6-benzyladenine (BA) after four weeks of culture period. Subculturing of organogenic calli in MS media with a similar hormonal composition resulted in shoot organogenesis after six weeks of culture cultivation. The highest shoot induction frequency (92%) was recorded on MS medium containing 4 µM BA in combination with 1 µM of α-naphthalene acetic acid (NAA). Further, well-developed roots were formed in MS media augmented with 6 µM of Indole acetic acid (IAA) in combination with 1 µM Kinetin (Kn). Cotyledon explants were exploited in vitro for the successful transformation of B. juncea. A binary vector comprised of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene under the transcriptional control of a glycinin promoter and with a basta selection marker was introduced into A. tumefaciens strain GV3101 via electroporation. EaDAcT gene is responsible for unusual triacylglycerol's production where the sn-3 position is esterified with acetate instead of the long-chain fatty acid found in the triacylglycerol's. The highest regeneration frequency (100%) of transgenic shoots was observed on MS medium supplemented with 4 µM BA plus 1 µM NAA in the presence of 25 mg l-1 basta and 160 mg l-1 timintin. The efficiency of stable transformation was found to be approximately 7% in the transgenic plants. Moreover, the transformed regenerated shoots were confirmed by PCR analysis using EaDAcT gene-specific primers.

Structure, DNA/proteins binding, docking and cytotoxicity studies of copper(II) complexes with the first quinolone drug nalidixic acid and 2,2'­dipyridylamine.

This work presents the synthesis, structural characterization and biological affinity of the newly synthesized copper(II) complexes with the first antibacterial quinolone drug nalidixic acid (nal) or N-donor ligand 2,2'­dipyridylamine (bipyam). [Cu(II)(nal)(bipyam)Cl], (2) reveals a distorted square pyramidal based geometry in Cu(II) atom confirmed by X-ray crystallography technique. The theoretical stabilities and optimized structures of the complex were obtained from DFT calculations. The ability of the complexes to bind with calf thymus DNA (CT DNA) were investigated by electronic absorption, fluorescence, circular dichroism, and viscosity measurements techniques. The experimental results reveal that the complexes strongly interact with CT DNA via intercalative mode but complex 2 exhibits the highest affinity giving Kb=3.91±0.13×106, M-1. The fluorescence spectroscopy measurements show that both complexes have the superior ability to the replacement of EtBr from DNA-bound EtBr solution and bind to DNA through intercalative mode. Both complex also shows the superior affinity towards proteins with comparatively high binding constant values which have been further revealed by fluorescence spectroscopy measurements. Molecular docking analysis indicates that the interaction of the complexes and proteins are stabilized by hydrogen bonding and hydrophobic interaction. Furthermore, the results of in vitro cytotoxicity reveal that the complex 2 has excellent cytotoxicity than 1 against human breast cancer cell lines (MCF-7).

Synthesis and characterization of self-assembled inorganic-organic hybrid arsenotungstates.

A series of 12 inorganic-organic hybrid 4f-substituted arsenotungstates decorated with 3d-based complexes along with acetate bridging, viz. {[Cu2(H2O)(1,10-phen)2(µ-CH3COO)2]4[Ln2(H2O)2(µ-CH3COO)2(α-AsW11O39)2]}2- (LnIII = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), have been synthesized. These compounds were isolated using a one-pot synthetic strategy with copper, lanthanoid, trilacunary arsenotungstate and 1,10-phenanthroline as precursors. They were characterized using various analytical techniques, such as single-crystal X-ray diffraction (SC-XRD), powder XRD (PXRD), Fourier transform IR (FT-IR) spectroscopy, UV-Vis spectroscopy and thermogravimetric analysis (TGA). In all these compounds, a dinuclear Ln2(ac)2 moiety is sandwiched between two monolacunary [AsW11O39]7- polyoxometalates (POMs), where the Ln2(ac)2 moiety is comprised of two acetate ligands in a µ-κO,O':κO fashion. Moreover, the anion is decorated by a copper-phenanthroline-acetate complex through a terminal O atom of the polyanion.

Synthesis and characterization of carbonate-encapsulated ytterbium- and yttrium-containing polyoxotungstates.

A sandwiched-type carbonate-encapsulated yttrium-containing arsenotungstate(III) has been synthesized under mild reaction conditions. The polyanion [NaCH3COO{Y2(H2O)3(B-α-AsW9O33)2(W2O5)(CO3)}]12- (1) was isolated as a solid crystalline material by the reaction of a YIII salt with the sodium salt of trilacunary [AsW9O33]9- in sodium acetate solution. The sodium salt of the polyanion, i.e. Na12[Na(CH3COO){Y2(AsW9O33)2(W2O5)(CO3)(H3O)3}]·22H2O (1a), was characterized by various analytical techniques, such as FT-IR, single-crystal X-ray diffraction (SC-XRD), TGA (thermogravimetric analysis), 13C NMR and ESI-MS (electrospray ionization mass spectrometry). SC-XRD studies revealed that the polyanion crystallizes in the triclinic space group P-1. The structure showed that the polyanion is a carbonate-encapsulated sandwich-type species, consisting of two trilacunary B-α-[AsW9O33]9-, with a lone-pair-containing AsIII heteroatom, together with two extra tungsten centres and two yttrium cations at the sandwich position, where CH3COO- and Na+ ions act as linkers between the two polyanion units. In addition, we have also synthesized two carbonate-encapsulated germanotungstates(IV), without lone-pair-containing heteroatoms, with the formula [Ln3(A-ß-GeW9O34)2(CO3)(H2O)3]13- [Ln = YIII (2) and YbIII (3)], i.e. Y2K3Na4[Y3(A-ß-GeW9O34)2(CO3)(H2O)3]·19H2O (2a) and YbK8Na2[Yb(A-ß-GeW9O34)2(CO3)(H2O)3]·16H2O (3a), and characterized them by FT-IR, SC-XRD, TGA and ESI-MS. Here, the lanthanide ions act as linkers, extending the structures into higher dimensions. Sodium and potassium ions also play a key role as linkers, further extending the structure. The packing shows the presence of certain hydrophilic pores within the structure.

Copper based coordination polymers based on metalloligands: utilization as heterogeneous oxidation catalysts.

This work presents the synthesis and characterization of two Cu(ii)-based coordination polymers prepared by utilizing two different Co(iii)-based metalloligands offering appended arylcarboxylic acid groups. Both coordination polymers are three-dimensional in nature and present pores and channels filled with water molecules. Both coordination polymers function as heterogeneous catalysts for the epoxidation of various olefins using O2 while employing isobutyraldehyde as the coreductor and for peroxide-mediated oxidation of assorted benzyl alcohols. The catalytic results illustrate efficient oxidation reactions, whereas the hot-fltration test and leaching experiments indicate the true heterogeneous nature of the catalysis.

Intramolecular stabilization of a catalytic [FeFe]-hydrogenase mimic investigated by experiment and theory.

The mono-substituted complex [Fe2(CO)5(µ-naphthalene-2-thiolate)2(P(PhOMe-p)3)] was prepared taking after the structural principles from both [NiFe] and [FeFe]-hydrogenase enzymes. Crystal structures are reported for this complex and the all carbonyl analogue. The bridging naphthalene thiolates resemble µ-bridging cysteine amino acids. One of the naphthyl moieties forms π-π stacking interactions with the terminal bulky phosphine ligand in the crystal structure and in calculations. This interaction stabilizes the reduced and protonated forms during electrocatalytic proton reduction in the presence of acetic acid and hinders the rotation of the phosphine ligand. The intramolecular π-π stabilization, the electrochemistry and the mechanism of the hydrogen evolution reaction were investigated using computational approaches.

Carbon-sulphur cross coupling reactions catalyzed by nickel-based coordination polymers based on metalloligands.

This work illustrates two Ni2+ based coordination polymers (CPs, 1-Ni and 2-Ni) synthesized using two related Co3+ based metalloligands offering appended arylcarboxylate groups. The crystal structure of 1-Ni displays a porous 3D network having well-defined major and minor pores whereas 2-Ni exhibits a somewhat densely packed structure. Both CPs supported the exchange of coordinated water molecules and the inclusion of iodine within their porous structure whereas binding studies illustrated that the Ni(ii) ion in these CPs can bind thiophenol, a reagent used in the C-S cross coupling reactions. The two CPs functioned as the reusable heterogeneous catalysts for the C-S cross coupling reactions between substituted aromatic halides and thiophenol as well as cyclohexanethiol and ethanethiol.

Phenylobacterium deserti sp. nov., isolated from desert soil.

A novel bacterial strain, designated YIM 73061T, was isolated from the Cholistan desert in Punjab, Pakistan, and characterized by using a polyphasic taxonomic approach. 16S rRNA gene sequence analysis revealed the highest levels of sequence similarity with respect to Phenylobacterium conjunctum FWC21T (97.6 %), Phenylobacterium lituiforme FaiI3T (97.4 %), Phenylobacteriumcomposti 4T-6T (97.0 %) and Phenylobacterium aquaticum W2-3-4T (96.8 %). Cells were Gram-stain-negative, aerobic and motile rods that formed orange colonies. The strain was oxidase- and catalase-positive. Growth occurred at 20-40 °C (optimum, 30-37 °C) at pH 5.0-8.0 (optimum, pH 7.0) and with 0-1 % (w/v) NaCl (optimum, 0-0.5 %). The major cellular fatty acids (>10 %) were summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The polar lipid profile consisted of phosphatidylglycerol and four unidentified glycolipids. The major isoprenoid quinone was ubiquinone-10 (Q-10). The G+C content of the genomic DNA was 66.8 mol%. Strain YIM 73061T showed low levels of DNA-DNA relatedness to P. conjunctum FWC21T (27.2±2.6 %), P. lituiforme FaiI3T (24.6±1.1 %) and P.composti 4T-6T (18.4±3.1 %). On the basis of phylogenetic inference, chemotaxonomic characteristics and phenotypic data, strain YIM 73061T should be classified as representing a novel species, for which the name Phenylobacterium deserti sp. nov. is proposed. The type strain is YIM 73061T (=DSM 103871T=CCTCC AB 2016297T).

Caldovatus sediminis gen. nov., sp. nov., a moderately thermophilic bacterium isolated from a hot spring.

A Gram-stain-negative, ovoid-shaped, aerobic, non-motile, catalase- and oxidase-positive, and moderately thermophilic bacterial strain, designated strain YIM 72346T, was isolated from a sediment sample collected from a hot spring in Tengchong county, Yunnan province, south-west China. Growth occurred at 37-50 °C (optimum, 45 °C), at pH 6.0-9.0 (optimum, pH 6.5-7.0) and in the presence of 0.5-1.0 % (w/v) NaCl (optimum, 0.5 %). The major cellular fatty acids were C18 : 1ω7c, C16 : 0, C19 : 0cyclo ω8c,and C18 : 1 2-OH. The genomic DNA G+C content was determined to be 69.8 mol%. The predominant ubiquinone was Q-10. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and two unidentified phospholipids. Bacteriochlorophyll α and carotenoic acids were not detected. Strain YIM 72346T was not observed for the accumulation of poly-ß-hydroxybutyrate. The strain shared highest 16S rRNA gene sequence identities with Crenalkalicoccus roseus YIM 78023T (93.3 %) and Craurococcus roseus NS130T (92.7 %), but formed a distinct lineage within the family Acetobacteraceae in the phylogenetic trees. On the basis of genotypic, phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM 72346T is considered to represent a novel genus and species of the family Acetobacteraceae, for which the name Caldovatus sediminis gen. nov., sp. nov. is proposed. The type strain of Caldovatus sediminis is YIM 72346T (=KCTC 52714T=CGMCC 1.16330T).

Thermus caldifontis sp. nov., a thermophilic bacterium isolated from a hot spring.

A thermophilic bacterial strain, designated YIM 73026T was isolated from a sediment sample collected from a hot spring in Tibet, PR China. The taxonomic position of the novel isolate was investigated by a polyphasic approach. The novel isolate was Gram-stain-negative, aerobic and rod-shaped. Colonies were circular, convex, opaque and yellow. The strain grew at 50-70 °C (optimum, 60 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of up to 1.0 % NaCl (w/v). Comparison of the 16S rRNA gene sequences of YIM 73026T and those of other members of the genus Thermus showed sequence similarities ranging from 91.2 to 97.5 %, with YIM 73026T showing closest sequence similarity to Thermus scotoductus SE-1T (97.5 %). DNA-DNA hybridization results, however, revealed that DNA-DNA reassociation values between YIM 73026T and T. scotoductus DSM 8553T (37.6 %), Thermusamyloliquefaciens YIM 77409T (34.5 %), Thermusantranikianii DSM 12462T (30.3 %), Thermuscaliditerrae YIM 77925T (28.6 %) and Thermustengchongensis YIM 77924T (27.3 %) were well below the 70 % limit for species identification. YIM 73026T contained MK-8 as the respiratory quinone, and iso-C15 : 0, iso-C16 : 0, iso-C17 : 0 and anteiso-C15 : 0 as the major cellular fatty acids (>10 %). The polar lipids consisted of one aminophospholipid, one phospholipid and two glycolipids. The genomic DNA G+C content of YIM 73026T was 65.4 mol%. On the basis of morphological, chemotaxonomic and genotypic characteristics, it is proposed that the isolate represents a novel species of the genus Thermus, for which the name Thermus caldifontis sp. nov. is proposed. The type strain is YIM 73026T (=NBRC 112415T=CCTCC AB 2016305T).

Nocardioides thalensis sp. nov., isolated from a desert.

A novel actinobacterial strain, designated NCCP-696T, was isolated from the Thal desert in Punjab, Pakistan, and characterized by using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain NCCP-696T belongs to the genus Nocardioides and showed the highest level of sequence similarity with respect to Nocardioides panacisoliGsoil 346T (98.2 %) and less than 96.4 % to the strains of other species of the genus Nocardioides. Cells of strain NCCP-696T were Gram-positive, aerobic, non-motile rods and formed cream-coloured colonies. The strain was positive for oxidase and catalase. Growth occurred at 20-42 °C (optimum 30-37 °C) at pH 5.5-9.0 (optimum pH 7.0) and with 0-4 % NaCl (optimum 0-2 %, w/v). Strain NCCP-696T contained Iso-C16 : 0, C18 : 1ω9c, C17 : 1ω8c and C17 : 0 as the predominant fatty acids and was found to have LL-2,6-diaminopimelic acid in the cell-wall peptidoglycan. The polar lipid profile consisted of phosphatidylinositol, phosphatidylglycerol and one unknown phospholipid. The major menaquinone was MK-8(H4) (98.7 %) while a minor amount (1.3 %) of MK-9(H2) was also detected. The DNA G+C content of the genomic DNA was 71.6 mol%. The DNA-DNA hybridization value of the isolate against the closely related type strain Nocardioides panacisoliGsoil 346T was 56.3±1.4. On the basis of the phylogenetic inference, chemotaxonomic characteristics and phenotypic data, strain NCCP-696T should be classified as a novel species, for which the name Nocardioides thalensis sp. nov. is proposed. The type strain is NCCP-696T (=DSM 103833T=CCTCC AB 2016296T).

Meiothermus luteus sp. nov., a slightly thermophilic bacterium isolated from a hot spring.

A slightly thermophilic, aerobic bacterium, designated YIM 72257T, was isolated from a sediment sample taken from a hot spring in Tengchong county, Yunnan province, south-west China. The isolate was Gram-stain-negative, non-sporulating and forms non-motile rods, appearing in chains. The isolate grew at 50-65 °C, pH 6.0-9.0 and with 0.5-1 % NaCl (w/v). 16S rRNA gene sequence analysis showed that strain YIM 72257T was most closely related to Meiothermus cateniformans LY1T (95.6 %), Meiothermus ruber DSM 1279T (95.1 %) and Meiothermus taiwanensis WR-30T (94.6 %). The genomic DNA G+C content of strain YIM 72257T was 62.6 mol%. The main cellular fatty acids (>5 %) were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0, iso-C17 : 0, iso-C15 : 0 and C16 : 0. The polar lipids consisted of an uncharacterized phospholipid and two glycolipids. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, strain YIM 72257T is proposed to be a representative of a novel species of the genus Meiothermus, for which the name Meiothermus luteus sp. nov. is proposed. The type strain is YIM 72257T (=KCTC 52599T=CCTCC AB 2017100T).

Two New Sandwich-Type Manganese {Mn5}-Substituted Polyoxotungstates: Syntheses, Crystal Structures, Electrochemistry, and Magnetic Properties.

Herein we report two pentanuclear MnII-substituted sandwich-type polyoxotungstate complexes, [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}(AsW9O33)2]9- and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2(SbW9O33)2]8- (bpy = 2,2'-bipyridine), whose structures have been obtained by single-crystal X-ray diffraction (SCXRD), complemented by results obtained from elemental analysis, electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. They consist of two [B-α-XW9O33]9- subunits sandwiching a cyclic assembly of the hexagonal [{Mn(bpy)}2Na(H2O)2(MnCl)2{Mn(H2O)}]9+ and [{Mn(bpy)}2Na(H2O)2(MnCl){Mn(H2O)}2]10+ moieties, respectively, and represent the first pentanuclear MnII-substituted sandwich-type polyoxometalates (POMs). Both compounds have been synthesized by reacting MnCl2·4H2O with trilacunary Na9[XW9O33]·27H2O (X = AsIII and SbIII) POM precursors in the presence of bpy in a 1 M aqueous sodium chloride solution under mild reaction conditions. SCXRD showed that the alternate arrangement of three five-coordinated MnII ions and two six-coordinated MnII ions with an internal Na cation formed a coplanar six-membered ring that was sandwiched between two [B-α-XW9O33]9- (X = AsIII and SbIII) subunits. The results of temperature-dependent direct-current (dc) magnetic susceptibility data indicated ferromagnetic interactions between Mn ions in the cluster. Moreover, alternating-current magnetic susceptibility measurements with a dc-biased magnetic field showed the existence of a ferromagnetic order for both samples. Electrochemistry studies revealed the presence of redox processes assigned to the Mn centers. They are associated with the deposition of material on the working electrode surface, possibly MnxOy, as demonstrated by electrochemical quartz crystal microbalance experiments.

Sphingobacteriumsoli sp. nov., isolated from soil.

A Gram-stain-negative, strictly aerobic, rod-shaped, non-motile, non-spore-forming bacterial strain, designated YIM X0211T, was isolated from a soil sample of Shiling County, Yunnan Province, south-west China. The new isolate was characterized taxonomically by using a polyphasic approach. The strain grew optimally at 30 °C, at pH 7.0 and with 0-3 % (w/v) NaCl. It was positive for catalase and oxidase but negative for H2S production. Comparative 16S rRNA gene sequence analysis showed that strain YIM X0211T fell within the cluster comprising Sphingobacterium species and clustered with Sphingobacterium mizutaii DSM 11724T (97.93 % similarity). The G+C content of the genomic DNA was 41.2 mol%. The predominant respiratory quinone was menaquinone MK-7. The major fatty acids were iso-C15 : 0 2-OH, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). The polar lipids consisted of phosphatidylethanolamine, sphingolipid, and several unknown phospholipids or lipids. The DNA-DNA hybridization value between strain YIM X0211T and S. mizutaii DSM 11724T was 42.3±0.4 %, which is below the 70 % limit for species delineation. These chemotaxonomic data supported the affiliation of strain YIM X0211T to the genus Sphingobacterium. Based on the recorded phenotypic and genotypic characteristics, it is determined that the isolate represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium soli sp. nov. is proposed. The type strain is YIM X0211T (=KCTC 42696T=CGMCC 1.15966T).

Tibeticola sediminis gen. nov., sp. nov., a thermophilic bacterium isolated from a hot spring.

Two closely related thermophilic bacterial strains, designated YIM 73013T and YIM 73008, were isolated from a sediment sample collected from a hot spring in Tibet, western Tibet province, China. The taxonomic positions of the two isolates were investigated using a polyphasic approach. The novel isolates were Gram-stain-negative, aerobic, short-rod-shaped and motile by means of a polar flagellum. They were oxidase- and catalase-positive and were able to grow at 30-55 °C (optimum, 37-45 °C), at pH 6.0-8.0 (optimum, pH 7.0) and with NaCl tolerance up to 1 % (w/v). Phylogenetic analyses based on 16S rRNA gene sequences showed that strains YIM 73013T and YIM 73008 formed a distinct lineage with respect to closely related genera in the family Comamonadaceae and shared highest 16S rRNA gene sequences similarities with Acidovorax caeni R-24608T (96.3 and 96.4 %, respectively). The respiratory quinone was ubiquinone-8 (Q-8) and the major cellular fatty acids observed were C17 : 1ω6c, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The genomic DNA G+C contents of strains YIM 73013T and YIM 73008 were 68.7 and 68.3 mol%, respectively. Based on the morphological, phylogenetic and chemotaxonomic results, the two isolates represent a novel species in a new genus, for which the name Tibeticola sediminis gen. nov., sp. nov. is proposed. The type strain of Tibeticola sediminis is YIM 73013T (=DSM 101684T=KCTC 42873T).