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An approach to the synthesis of novel sulphonamide-based siderophores using a serinetrimer, as a readily accessible scaffold, is disclosed in this paper. The methodological studies involved have also resulted in the identification of an uncommon example of desmotropy.

Disrupted iron homeostasis is associated with several neurodegenerative diseases, including Alzheimer’s disease (AD), and may be partially modulated by genetic risk factors. Here we evaluated whether subcortical iron deposition is associated with ApoE genotype, which substantially affects risk for late-onset AD. We evaluated differences in subcortical quantitative susceptibility mapping (QSM), a type of MRI sensitive to cerebral iron deposition, between either ApoE4 (E3E4+E4E4) or ApoE2 (E2E3+E2E2) carriers and E3 homozygotes (E3E3) in 27,535 participants from the UK Biobank (age: 45-82 years). We found that ApoE4 carriers had higher hippocampal (d=0.036; p=0.012) and amygdalar (d=0.035; p=0.013) magnetic susceptibility, particularly individuals aged 65 years or older, while those carrying ApoE2 (which protects against AD) had higher QSM only in the hippocampus (d=0.05; p=0.006), particularly those under age 65. Secondary diffusion MRI microstructural associations in these regions revealed greater diffusivity and less diffusion restriction in E4 carriers, however no differences were detected in E2 carriers. Disease risk conferred by ApoE4 may be linked with higher subcortical iron burden in conjunction with inflammation or neuronal loss in aging individuals, while ApoE2 associations may not necessarily reflect unhealthy iron deposits earlier in life.

The current demand for more sustainable catalytic processes has seen a clear shift from the classical noble-metal-based catalysts to cheaper and abundant metals. The focus on earth-abundant transition-metal-based catalysts has been marred by synthetic and characterization challenges but is ultimately achieving the desired catalytic results. To extract the catalytic potential of earth-abundant transition-metal-based complexes, great care concerning the design of the supporting ligands is required. Under certain conditions, monoanionic bidentate chelates present a good strategy to tackle those goals. The 2-iminopyrrolyl framework is a good example of that: Its huge electronic and steric tuning potential has paved the way for diverse coordination chemistries of first-row transition metals, from manganese to copper. With such metal complexes in hand, several catalytic applications have been studied, namely polymerization, hydrofunctionalization and click chemistry. This chapter features the main catalytic achievements of complexes of earth-abundant metals bearing 2-iminopyrrolyl ligands and their respective mechanistic insights and structure–reactivity relationships.

The catalytic functionalization of C–H, C–OH and C–C bonds belongs to the most important processes in nature and the industry. In nature, this process occurs via involvement of enzymes, effectively and selectively, usually with very high turnover numbers. The pivotal role in enzymatic activity is played by the metal center cofactors, which involve several bioavailable transition metals, such as, iron, copper, manganese and zinc. In the industry, bond functionalization requires the presence of metal catalysts; therefore, a bio-inspired design of metal catalysts is a challenging approach. The recent advances in the catalysis of industrially important reactions, namely the oxidation and hydrocarboxylation of alkanes, the oxidation of alcohols and C–C coupling are reported. Convenient, environmentally friendly methods are presented, and the role and efficacy of the various transition-metal (iron, copper, zinc, manganese, nickel, vanadium, palladium and cobalt) catalysts are explored.

Reduction behaviour of Fe³⁺/AI₂O₃ obtained by the decomposition of the oxalate precursor has been investigated by employing X-ray diffraction (XRD), Mössbauer spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. Calcination of Fe³⁺/AI₂O₃ at or below 1070 K yields mainly a poorly ordered, fine particulate form of η-Al_2−xFe_xO₃. Calcination at or above 1220 K yields α-AI_2−xFe_xO₃. Reduction of Fe³⁺/AI₂O₃ samples calcined at or below 1070 K gives the FeAI₂O₄ spinel on reduction at 870 K; samples calcined at or above 1220 K give AI_2−xFe_xO₃ with a very small proportion of metallic iron. Fe³⁺/AI₂O₃ samples calcined at 1220 K or above yield metallic iron and a very small proportion of the spinel on reduction below 1270 K. In the samples reduced at or above 1270 K, the main product is metallic iron in both ferromagnetic and superparamagnetic forms. The oxalate precursor route yields more metallic iron than the sol–gel route.

Oxidative damage and response are major features of Alzheimer's disease and other neurodegenerative diseases. Metal-catalyzed oxidative events are at the center of radical formation and abnormalities in iron and copper have been noted. In this review, we consider the evidence implicating the central role of metals.

Parkinson's disease is a common neurodegenerative disorder characterized clinically by motor dysfunction. The primary pathological changes in the Parkinsonian brain are the degeneration of pigmented dopaminergic neurons of the substantia nigra and the development of pathological inclusions called Lewy bodies. Progressive cell loss in Parkinson's disease is suggested to result from self-sustaining mechanisms related to oxidative mechanisms and mitochondrial dysfunction. A common factor linking oxidative damage, mitochondrial dysfunction, and the development of Lewy bodies in Parkinson's disease is the presence of a significant and pathological increase in the amount of iron in the degenerating substantia nigra. The role of iron in biochemical pathways proposed to mediate these mechanisms and their association with the etiology of Parkinson's disease is discussed.

Injections of iron salts into the sensorimotor cortex, hippocampus, and amygdala of experimental animals results in chronic recurrent focal paroxysmal electroencephalographic discharges, behavioral convulsions, and electrical seizures. The induction of epilepsy may be related to generation of free radicals, lipid peroxidation of neuronal membranes, increased intracellular calcium concentrations through reverse action of sodium-calcium exchanger/reduced activity of plasma membrane or endoplasmic reticulum calcium ATPases, increased release of excitatory neurotransmitters, including aspartate and glutamate, and increased influx of ions through glutamate receptors. Some of the above effects of iron can be abrogated by inhibitors of phospholipase A₂ (PLA₂) indicating that the damaging effects of iron may be due to perturbation of the lipid environment essential to normal functioning of membrane proteins. Iron in hemoglobin, or by itself, is also likely to be the cause of human epilepsy, in instances where there is increased iron load in the brain. These include subarachnoid hemorrhage, intraparenchymal hemorrhages due to head injury and stroke, malaria, human immunodeficiency virus encephalitis, and possibly, neuroleptic drug use. A reduced level of haptoglobin, a hemoglobin-binding protein, has also been observed in select kindred relatives affected with familial idiopathic epilepsy. An accumulation of iron has been observed in the motor cortex with age, and it is possible that this might contribute to the increased incidence of epilepsy among the elderly. Iron accumulates with time in rat hippocampus after kainate-induced epilepsy. The accumulation occurs in oligodendrocytes, and is likely to be a reflection of the high levels of iron in the extracellular space. The accumulation of iron is correlated with increased expression of the divalent metal transporter-1 in astrocytes in the glial scar and increased expression of heme oxygenase-1 in reactive astrocytes and microglia, as well as degenerating neurons at the edge of the scar. The increased divalent metal transporter-1 expression could lead to increased uptake of iron, followed by redistribution to the extracellular space. In this model, iron is the consequence of epilepsy, although it is possible that it can also be a cause of epilepsy. Further work is necessary to elucidate the effects of lipid peroxidation of the cellular membranes on function of membrane proteins and the role of phospholipases, including PLA₂, in perturbing the lipid environment. The possible presence of iron in the human brain after epilepsy also needs to be elucidated. The causes of dysregulation of iron in the glial scar after neuronal injury need to be studied. In addition, possible beneficial effects of iron chelators, antioxidants that cross the blood-brain barrier, or neuroprotective gene induction on epilepsy, need to be evaluated.

New inorganic-organic hybrid open-framework materials of the phosphate - oxalate family, [Fe₂(H₂O₂- (HPO₄)₂(C₂O₄)]·H₂O) (I), [Fe₂(H₂O₂- (HPO₄)₂(C₂O₄)]·2H₂O(II), [C₃N₂H₁₂]- [Fe₂(HPO₄)₂(C₂O₄)_1.5]₂(III), and [C₃N₂OH₁₂][Fe₂(HPO₄)₂(C₂O₄)_1.5]₂(IV) have been synthesized hydrothermally in the presence of structure-directing amines. The amine molecules are incorporated inIII and IV, whereas I and II are devoid of them. The oxalate units act as a bridge between the layers in all the compounds. The layers in I and II are entirely inorganic, being formed by FeO₆ and PO₄ units, whereas in III and IV oxalate units constitute the inorganic layers and act as the bridge between these layers. Such a dual role of the oxalate unit is unique and noteworthy. The formation of two types of inorganic layers in I and II consisting of four-, six-, and eight-membered rings, indicates the interconversions between the various rings in the phosphate - oxalates to be facile. All the phosphate - oxalates show antiferromagnetic ordering at low temperatures.

A study was conducted to investigate the efficiency of unvegetated subsurface flow constructed wetland in leachate treatment. Three reactors (I, II and III) filled with different media of granite, gravel and sand, respectively, were placed in descending order height in order to allow gravity flow of leachate to each reactor. Raw leachate was let to flow continuously from Reactor I to III at a predetermined rate. The leachate was analyzed for chemical oxygen demand (COD) and iron before and after the treatment. The results show that COD removal efficiency was 15.4, 22.6 and 29.2% for Reactor I, II and III, respectively. The removal efficiency for iron in Reactors I, II and III were 20.3, 35.2 and 38.5%, respectively. The overall average COD and iron removal at the end of process were 53.6 and 68.1%, respectively.

The effect of different concentrations of iron on the Azotobacter chroococcum growth and PHB accumulation as well as on the characteristics of the isolated native PHB granules and the purified polymer was investigated under conditions of fed-batch fermentations. A new hydrophobic fluorescent P8 was used to study an effect of iron concentration on the bacterial cell and the isolated native PHB granules. An increase of the iron concentration in growth medium accelerated A. chroococcum growth and total PHB yield. The observed changes in P8/bacterial cells system fluorescence intensity under experiment conditions reflects alterations of the of cells physicochemical state. The increase of iron concentration in growth media Azotobacter chroococcum led to higher impurity of the recovered PHB granules samples and resulted in a lowering of tensile strength and elasticity of the polymeric films.

Based on the real-time quantitative polymerase chain reaction technology and Fisher discriminant analysis method, a new approach is established to rapidly discern the bean curd with blood from duck blood, pig or cattle. Through the primer design and specificity validation of duck, pig and cattle, the real-time quantitative polymerase chain reaction technology is used to identify the components of 81 samples of blood curd. The discriminant analysis model of species identification of bean curd with blood of duck, pig or cattle is established on the basis of taking two indicators, the content of iron and that of protein, as discriminant factors and using SPSS 19.0 to calculate the discriminant coefficient. The result shows that, in the case of Fisher linear discriminant analysis model, the accuracy of identifying the authenticity of bean curd with duck blood, pig blood or cattle blood is respectively 83.0%, 82.7%, 75.3%. Through the combination of iron and protein content with Fisher discriminant analysis method, the bean curd with duck blood, pig blood, or cattle blood can be identified relatively easily. This is a new and simple way of distinguishing bean curd with blood.