Distinct structures of coordination polymers incorporating flexible triazole-based ligand: topological diversities, crystal structures and property studies

Maternal Pyrroloquinoline Quinone Supplementation Improves Offspring Liver Bioactive Lipid Profiles throughout the Lifespan and Protects against the Development of Adult NAFLD

Maternal obesity and consumption of a high-fat diet significantly elevate risk for pediatric nonalcoholic fatty liver disease (NAFLD), affecting 10% of children in the US. Almost half of these children are diagnosed with nonalcoholic steatohepatitis (NASH), a leading etiology for liver transplant. Animal models show that signs of liver injury and perturbed lipid metabolism associated with NAFLD begin in utero; however, safe dietary therapeutics to blunt developmental programming of NAFLD are unavailable. Using a mouse model of maternal Western-style diet (WD), we previously showed that pyrroloquinoline quinone (PQQ), a potent dietary antioxidant, protected offspring of WD-fed dams from development of NAFLD and NASH. Here, we used untargeted mass spectrometry-based lipidomics to delineate lipotoxic effects of WD on offspring liver and identify lipid targets of PQQ. PQQ exposure during pregnancy altered hepatic lipid profiles of WD-exposed offspring, upregulating peroxisome proliferator-activated receptor (PPAR) α signaling and mitochondrial fatty acid oxidation to markedly attenuate triglyceride accumulation beginning in utero. Surprisingly, the abundance of very long-chain ceramides, important in promoting gut barrier and hepatic function, was significantly elevated in PQQ-treated offspring. PQQ exposure reduced the hepatic phosphatidylcholine/phosphatidylethanolamine (PC/PE) ratio in WD-fed offspring and improved glucose tolerance. Notably, levels of protective n - 3 polyunsaturated fatty acids (PUFAs) were elevated in offspring exposed to PQQ, beginning in utero, and the increase in n - 3 PUFAs persisted into adulthood. Our findings suggest that PQQ supplementation during gestation and lactation augments pathways involved in the biosynthesis of long-chain fatty acids and plays a unique role in modifying specific bioactive lipid species critical for protection against NAFLD risk in later life.

Crystal Structure and Magnetic Properties of Trinuclear Transition Metal Complexes (MnII, CoII, NiII and CuII) with Bridging Sulfonate-Functionalized 1,2,4-Triazole Derivatives

Here we present the synthesis, structure and magnetic properties of complexes of general formula (Mn)(Me₂NH₂)₄][Mn₃(μ-L)₆(H₂O)₆] and (Me₂NH₂)₆[M₃(μ-L)₆(H₂O)₆] (M = Co^II, Ni^II and Cu^II); L⁻² = 4-(1,2,4-triazol-4-yl) ethanedisulfonate). The trinuclear polyanions were isolated as dimethylammonium salts, and their crystal structures determined by single crystal and powder X-ray diffraction data. The polyanionic part of these salts have the same molecular structure, which consists of a linear array of metal(II) ions linked by triple N1-N2-triazole bridges. In turn, the composition and crystal packing of the Mn^II salt differs from the rest of the complexes (with six dimethyl ammonia as countercations) in containing one Mn⁺² and four dimethyl ammonia as countercations. Magnetic data indicate dominant intramolecular antiferromagnetic interactions stabilizing a paramagnetic ground state. Susceptibility data have been successfully modeled with a simple isotropic Hamiltonian for a centrosymmetric linear trimer, H = −2J (S₁S₂ + S₂S₃) with super-exchange parameters J = −0.4 K for Mn^II, −7.5 K for Ni^II and −45 K for Cu^II complex. The magnetic properties of these complexes and their easy processing opens unique possibilities for their incorporation as magnetic molecular probes into such hybrid materials as magnetic/conducting multifunctional materials or as dopant for organic conducting polymers.

Bent-bis(triazolyl)-based coordination polymers tuned by dicarboxylate ligands: syntheses, structures and properties

Seven new coordination polymers based on the bent 1,1'-(oxybis(1,4-phenylene))-bis(1H-1,2,4-triazole) ligand, with diverse structures and novel topologies, that are directed by the dicarboxylate ligands.

Synthesis, Structures, and Water Adsorption of Two Coordination Polymers Constructed by M(II) (M = Ni (1) and Zn (2)) with 1,3-Bis(4-Pyridyl)Propane (bpp) and 1,2,4,5-Benzenetetracarboxylate (BT4-) Ligands

Two coordination polymers (CPs), with chemical formulas {[Ni₂(bpp)₂(BT)(H₂O)₆] 1.5(EtOH) 1.5H₂O}_n (1) and [Zn(bpp)(BT)_0.5]·5H₂O (2) (bpp = 1,3-bis(4-pyridyl)propane, and BT⁴⁻ = tetraanion of 1,2,4,5-Benzenetetracarboxylic acid), have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. In compound 1, the coordination environments of two crystallographically independent Ni(II) ions are both distorted octahedral bonded to two nitrogen donors from two bpp ligands and four oxygen donors from one BT^4- ligand and three water molecules. Both bpp and BT⁴⁻ act as bridging ligands with bis-monodentate and 1,4-bis-monodentate coordination modes, respectively, connecting the Ni(II) ions to form a 2D layered metal-organic framework (MOF). Adjacent 2D layers are then arranged orderly in an ABAB manner to complete their 3D supramolecular architecture. In 2, the coordination environment of Zn(II) ion is distorted tetrahedral bonded to two nitrogen donors from two bpp ligands and two oxygen donors from two BT⁴⁻ ligands. Both bpp and BT^4- act as bridging ligands with bis-monodentate and 1,2,4,5-tetrakis-monodentate coordination modes, respectively, connecting the Zn(II) ions to form a 3D MOF. The reversible water de-/adsorption behavior of 1 between dehydrated and rehydrated forms has been verified by cyclic Thermogravimetric (TG) analyses through de-/rehydration processes. Compound 1 also exhibits significant water vapor hysteresis isotherms.

Ph-Directed Assembly of Two 2D Copper(II) Coordination Polymers Based on Mixed Benzenetetracarboxylate and 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-Tetrafluorobenzene Ligands: Syntheses, Structures and Properties

Two new Cu(II) coordination polymers [Cu(Fbtx)(H2btec)(H2O)2]n and {[Cu(Fbtx)(btec)0.5(H2O)2]·H2O}n have been synthesised by hydrothermal reactions of Cu(II) nitrate with 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under different pH conditions. The first complex has a two-dimensional four-connected layer structure with a 44-sql topology, whereas the second has a two-dimensional three-connected brick-wall network. The luminescence properties of the complexes in the solid state and their thermal stabilities have also been studied.

Rigid versus semi-rigid bis(imidazole) ligands in the assembly of two Co(ii) coordination polymers: structural variability, electrochemical properties and photocatalytic behavior

Two Co(ii) complexes with 1,2,4,5-cyclohexanetetracarboxylate, rigid or semi-rigid bis(imidazole) ligands were hydrothermally synthesized. Both compounds showed high photocatalytic activity for MB degradation.

A series of transition metal coordination polymers based on a rigid bi-functional carboxylate–triazolate tecton

By utilizing a pre-designed bi-functional ligand, five new transition-metal-based coordination polymers have been constructed and structurally characterized, along with their luminescence or magnetic properties.

Role of bioactive fatty acids in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is characterized by fat deposition in hepatocytes, and a strong association with nutritional factors. Dietary fatty acids are classified according to their biochemical properties, which confer their bioactive roles. Monounsaturated fatty acids have a dual role in various human and murine models. In contrast, polyunsaturated fatty acids exhibit antiobesity, anti steatosic and anti-inflammatory effects. The combination of these forms of fatty acids—according to dietary type, daily intake and the proportion of n-6 to n-3 fats—can compromise hepatic lipid metabolism. A chemosensory rather than a nutritional role makes bioactive fatty acids possible biomarkers for NAFLD. Bioactive fatty acids provide health benefits through modification of fatty acid composition and modulating the activity of liver cells during liver fibrosis. More and better evidence is necessary to elucidate the role of bioactive fatty acids in nutritional and clinical treatment strategies for patients with NAFLD.

A series of pyridyl-amide-based ZnII/CdII coordination polymers and their polypyrrole-functionalized composite materials for tuning their photocatalytic properties

Six pyridyl-amide-based Zn^II/Cd^II coordination polymers have been solvothermally synthesized and decorated by polypyrrole for tuning their photocatalytic properties under visible irradiation.

An enhanced extended hook method to realize tetranuclear metal clusters embedded in energetic metal–organic framework channels

Rare tetranuclear Zn clusters were successfully embedded into energetic 3D metal–organic framework channels by an extended bifunctional tetrazolate–carboxylate hook ligand.

Polycarboxylate-directed various Co(ii) complexes based on a “V”-like bis-pyridyl-bis-amide derivative: construction, electrochemical and photocatalytic properties

Six Co(ii) complexes have been hydrothermally synthesized with mixed ligands. The effects of the polycarboxylates on the structures of the title complexes have been discussed.