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Considering the current importance of unsymmetrical mono‐ and di‐N‐functionalized ethylene side‐bridged (sb) cyclams and the need to have their C‐appended derivatives bearing an additional function dedicated to a conjugation to an external moiety as a targeting biomolecule, we have developed a general procedure to obtain orthogonally N‐protected sb‐cyclams with a benzyl or a Boc group. Despite the lack of symmetry of the compounds, this methodology allows the specific protection of one or the other remaining secondary amine function. [ABSTRACT FROM AUTHOR]

The acid–base and copper(ii) coordination properties of three previously described cyclam derivatives are reported. Potentiometry, mass spectrometry, UV-vis absorption spectroscopy, electrochemistry and theoretical calculations were combined to investigate the protonation and binding properties of Bn-cyclam-EtOH (L1), oxo-cyclam-EtOH (L2) and oxo-Bn-cyclam-EtOH (L3). These three cyclams are C-functionalized by a hydroxyethyl pendant arm and display either one N-benzyl group and/or an amide replacing one macrocyclic secondary amine. The N-benzylic substitution has a significant effect of lowering the basicity of the corresponding protonation sites, while the presence of the amide function lowers the first protonation constants of the ligands. Regardless of the system considered, ESI mass spectrometry showed that only monocupric chelates are formed. Compared to the literature data, the stability constants measured by potentiometry (pCu L1 = 14.67; pCu L2 = 16.95; pCu L3 = 15.28) showed that: (i) the C-appended group has a negligible influence on Cu2+ complexation, (ii) N-benzylation decreases the cupric complex stability, and (iii) the “oxo” function significantly increases the stability of the Cu2+ complex. Furthermore, UV-vis absorption versus pH measurements are in excellent agreement with the potentiometric titrations and show an equal involvement of the four nitrogen atoms in L1 and the strong binding properties of L2 and L3 related to the deprotonation of the carboxamide. The electrochemistry parameters determined by cyclic voltammetry showed the predominance of the [CuL1]2+, [CuL2-H]+ and [CuL3-H]+ species but also the irreversibility of the three Cu2+/Cu+ systems. Finally, density functional theory (DFT) and multiconfigurational CASSCF/NEVPT2 calculations confirmed that the protonation of the cupric complexes occurs at the oxygen atom of the amide group of the “oxo” ligands, which is in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • An important literature on the Pd(II) coordination with small polyazacycloalkanes (three and four nitrogen atoms) is given. • Examples of the use of aza-ligands with 103Pd and 109Pd radioisotopes for therapeutic purposes are also presented. • The coordination of Pd(II) ion is mainly square planar, often slightly distorted depending on the nature of the ligand. • This review leads us to expect ligands based on cyclam should be suitable for Pd(II) coordination. In view of the growing interest of palladium(II) for medical applications and the important role of polyamines in exploiting its properties, this review combines the published literature on the coordination of Pd(II) with small polyazacycloalkanes (three and four nitrogen atoms), such as 1,4,7-triazacyclononane, 1,5,9-triazacyclododecane, cyclen, cyclam, as well as their derivatives or close scaffolds such as pyclen. Finally, the rare examples of the use of aza-ligands with 103Pd and 109Pd radioisotopes for therapeutic purposes are also presented. The coordination of the Pd(II) ion is mainly square planar, often slightly distorted depending on the nature of the ligand. A few rare five-coordinated complexes with square pyramidal or trigonal bipyramidal geometries have been described in cases where the steric or topological requirements of the ligand outweigh the loss of stabilization due to geometric distortion. Considering the marked structural preference of Pd(II) for square planar coordination, this review allows us to propose hypotheses on the nature of new Pd(II) complexes whose properties could be exploited, especially in nuclear medicine. [ABSTRACT FROM AUTHOR]

Abstract: The host–guest binding interaction between two symmetrical octaazaligands containing a para-xylenyl spacer and triphosphate anion is reported. The ligands studied here are the para-xylenylbiscyclam (AMD3100) and its linear analogue the para-xylenylbis-1,4,8,11-tetraazaundecane, obtained by linking the two corresponding cyclic or open-chain tetraamines. The purpose of this study is to evaluate the effect of these two different architectures on the factors governing the recognition of the triphosphate anion. The results clearly indicate that compared to its biscyclam analogue, the linear octaamine presents a better triphosphate recognition in the whole p[H] range. On the one hand, the capacity of the octaamine to form easily polyprotonated species constitutes the driving force favouring the formation of ternary species, and, on the other hand, the adaptability of this receptor in organizing hydrogen bonds represents also a benefit for the binding of triphosphate substrate. The polyprotonated ligand is sufficiently flexible to wrap itself round the anion in a way to achieve an optimal fit for the best host–guest recognition. [Copyright &y& Elsevier]

Plant litter decomposition is an essential ecosystem function in temperate streams. Both riparian vegetation and decomposer communities are major determinants of the decomposition efficiency and the interactions occurring within litter mixtures. However, the extent to which such litter mixture interactions are affected by combined shifts in litter traits and decomposer community is not well understood. We used leaf litter from 10 European tree species in order to study litter decomposition and litter mixture effects occurring in two-species litter mixtures in a temperate forested stream of northwestern France. The study distinguished between (1) decomposition involving microorganisms alone or together with invertebrates, and (2) decomposition involving litter mixtures of similar or dissimilar nutrient content. Increasing mean litter nutrient concentration favored both microbial activity and litter decomposition rate. Surprisingly, the highest litter mixture effects occurred in mixtures containing two nutrient-rich litters and occurred mainly in macroinvertebrate presence. Both the "mass ratio hypothesis," expressed as the community-weighted mean traits (TraitCWM), and the "niche complementarity hypothesis," expressed as the functional dissimilarity of litter traits (TraitFD), contributed to explain litter mixture effects. However, TraitCWM was found to be a better predictor than TraitFD. Finally, when evaluating the individual contributions of litter nutrients, calcium and magnesium appeared as important drivers of litter mixture effects. Our findings suggest that the mass ratio hypothesis overrules the niche complementarity hypothesis as a driver of litter diversity effects. Our study highlights the key importance of macroinvertebrates and of leaf nutrients, such as Ca and Mg, which are often neglected in decomposition studies in streams. [ABSTRACT FROM AUTHOR]

Although the concept of theranostics is neither new nor exclusive to nuclear medicine, it is a particularly promising approach for the future of nuclear oncology. This approach is based on the use of molecules targeting specific biomarkers in the tumour or its microenvironment, associated with optimal radionuclides which, depending on their emission properties, allow the combination of diagnosis by molecular imaging and targeted radionuclide therapy (TRT). Copper-64 has suitable decay properties (both β+ and β- decays) for PET imaging and potentially for TRT, making it both an imaging and therapy agent. We developed and evaluated a theranostic approach using a copper-64 radiolabelled anti-CD138 antibody, [64Cu]Cu-TE1PA-9E7.4 in a MOPC315.BM mouse model of multiple myeloma. PET imaging using [64Cu]Cu-TE1PA-9E7.4 allows for high-resolution PET images. Dosimetric estimation from ex vivo biodistribution data revealed acceptable delivered doses to healthy organs and tissues, and a very encouraging tumour absorbed dose for TRT applications. Therapeutic efficacy resulting in delayed tumour growth and increased survival without inducing major or irreversible toxicity has been observed with 2 doses of 35 MBq administered at a 2-week interval. Repeated injections of [64Cu]Cu-TE1PA-9E7.4 are safe and can be effective for TRT application in this syngeneic preclinical model of MM. [ABSTRACT FROM AUTHOR]

Cyclam-picolinate chelators were functionalized via click chemistry with an additional carboxyl group for subsequent bioconjugation to antibodies or for the modification of the overall charge of the corresponding 64Cu-radiocomplexes. The C-aryl functionalization strategy developed here preserves the chemical properties of the radiocomplexes whilst deeply enhancing their applications within nuclear medicine. [ABSTRACT FROM AUTHOR]

The limited use of palladium‐103 and ‐109 radionuclides for molecular radiotherapy is surely due to the lack of appropriate ligands capable of fulfilling all criteria required for application in nuclear medicine. Furthermore, the thermodynamic properties of these complexes in solution remain difficult to establish. The challenge is compounded when considering that radiolabeling of compounds for translation to clinical trials requires fast complexation. Thus, the coordination of Pd(II) and 103/109Pd‐nuclides is a huge challenge in terms of molecular design and physicochemical characterization. Herein, we report a comprehensive study highlighting TE1PA, a monopicolinate cyclam – already established in nuclear imaging with 64Cu‐PET (positron emission tomography) imaging tracers – as a highly relevant chelator for natural Pd and subsequently 109Pd‐nuclide. The structural, thermodynamic, kinetic and radiolabeling studies of Pd(II) with TE1PA, as well as the comparison of this complex with three structurally related derivatives, support palladium‐TE1PA radiopharmaceuticals as leading candidates for targeted nuclear medicine. [ABSTRACT FROM AUTHOR]

We describe an easy synthesis of original C-functionalized cyclam derivatives based on the efficient bisaminal template method. In the perspective of developing bifunctional chelating agents (BCAs), this new synthetic strategy offers the possibility of introducing various coupling functions on one carbon atom in the β-N position of the macrocycle, leaving the four nitrogen atoms available for the introduction of pendant coordinating arms. The methodology is based on a keystone C-functionalized oxo-cyclam bisaminal intermediate that is obtained by cyclization of a preorganized tetraamine using various methyl acrylate analogues. These compounds constitute valuable precursors for selective preparation of mono- and di-N-protected C-functionalized cyclams and C-functionalized cyclams, cross-bridged cyclams, and oxo-cyclam derivatives. This approach was successfully adapted to the synthesis of three BCAs with great interest especially for biomedical applications: TETA, TE2A, and CB-TE2A. The structures of different intermediates and Cu(II) complexes of C-functionalized cyclam derivatives were confirmed using single-crystal X-ray diffraction, while reactivity of the key intermediates was rationalized by the analysis of the electrostatic potentials calculated at the TPSSh/6-311G(d,p) level. [ABSTRACT FROM AUTHOR]

Abstract: The host–guest binding interaction involving two bis-linear tetraamines, namely 1,3-xylenylbis-1,4,8,11-tetraazaundecane (L1 ) and 2,6-dimethylpyridinylbis-1,4,8,11-tetraazaundecane (L2 ), with triphosphate and ATP anions is reported. These polyamines, obtained by linking two linear tetraamines with an aromatic spacer, are able to form in aqueous solution and around neutral p[H], very stable complexes with the targeted anionic substrates by means of electrostatic interactions such as hydrogen bonds. This study, investigated by potentiometric and NMR measurements in solution, clearly highlights the different coordination schemes exhibited by these anions according to their inorganic or organic nature; particularly, concerning ATP, the role of the aromatic linker in the complexation, through π-stacking interactions with the adenine part, is evidenced. [Copyright &y& Elsevier]

An easy-to-run route to a new ditopic ligand possessing linear and cyclic tetraaza subunits is described. In the first step, the reaction consists in the preparation of a triprotected cyclam bearing a 3-bromopropyl pendant side chain. A subsequent reaction with a bisaminal protected linear tetraamine gives, after deprotection, the desired ditopic ligand. [ABSTRACT FROM AUTHOR]

Temperature inducible phenotypic plasticity is a major player in plant responses to climate warming. Functional responses and their role in determining thermal plasticity of plants remain poorly understood. Our objective was to compare trait responses of six populations of Ludwigia peploides resulting from seed from Oceanic climate and from Mediterranean climate after an exposure at three temperatures (16, 24, and 30°C). A comparative analysis showed that at 30°C, the six populations of L. peploides shared different morphological responses, whereas a common pattern of morphological responses was found for the six populations at 16°C. At 16°C, the growth was very low suggesting a stress. At 30°C, the three Mediterranean populations of L. peploides accumulated ≈ sevenfold more total biomass than the populations from Oceanic region. Despite drawing similar response pattern to temperature, the populations showed several different metabolic responses. The thermal plastic responses to the highest temperature differed according to the origin of the populations. The Mediterranean populations of L. peploides could be better adapted to rising temperature. These abilities could allow them to take advantage from climate warming if the temperature is not warming up to temperature above a critical threshold. [ABSTRACT FROM AUTHOR]

Agriculture is changing to rely on agroecological practices that take into account biodiversity, and the ecological processes occurring in soils. The use of agricultural biostimulants has emerged as a valid alternative to chemicals to indirectly sustain plant growth and productivity. Certain BS have been shown to select and stimulate plant beneficial soil microorganisms. However, there is a lack of knowledge on the effects and way of action of the biostimulants operating on soil functioning as well as on the extent and dynamic of these effects. In this study we aimed to decipher the way of action of a seaweed and amino-acids based biostimulant intended to be applied on soil crop residues to increase their microbial mineralization and the further release of nutrients. By setting-up a two-phase experiment (soil plant-growing and soil incubation), our objectives were to (1) determine the effects of the soil biostimulant over time on the active soil bacteria and fungi and the consequences on the organic carbon mineralization in bare soils, and (2) assess the biostimulant effects on soil microorganisms relatively to plant legacy effects in planted soils. We demonstrated that the soil biostimulant had a delayed effect on the active soil microorganisms and activated both plant growth promoting bacteria and saprophytes microorganisms at the medium-term of 49 days. However, the changes in the abundances of active microbial decomposers were not associated to a higher mineralization rate of organic carbon derived from soil and/or litter. The present study assessed the biostimulant beneficial effect on active soil microbial communities as similar as or even higher than the legacy effects of either A. thaliana or T. aestivum plants. We specifically showed that the biostimulant increased the active fungal richness to a higher extent than observed in soils that previously grew the two plants tested. [ABSTRACT FROM AUTHOR]

We investigated whether perennial soil organic amendments of pig slurry (PS) and methanized pig slurry (MPS) affect active bacterial communities and change the diversity and the C-flux of Volatile Organic Compounds (VOCs) emitted by soils compared to control plots without any fertilization (C). The long term effects of the fertilization history of the amendments and the short term impact of the organic inputs were both investigated by measuring VOCs emissions using a Proton Transfer Reaction-Mass Spectrometer (PTR-MS) and by analyzing active bacterial diversity by MiSeq Illumina sequencing just before and up to 64 days following the inputs. Soil VOCs emissions (diversity and fluxes) naturally varied with temperature and rainfall variations, irrespective of manure inputs. No effect of the 5-yr fertilization history was observed on bacterial communities’ composition and on soil VOCs emissions. However, both manure inputs (PS and MPS) were associated with an inoculation of γ- Proteobacteria ( Pseudomonas sp. and/or Marinospirillum sp.) to the soil on top of which PS inputs activated native soil Bacillus sp. (Firmicutes). VOCs spectra was mainly dominated by methanol and acetonitrile, the acetonitrile emissions not depending on the organic practices. C-VOCs fluxes from the soil to the atmosphere varied from 12 to 76 μg of C-VOCs h −1 m −2 in the control plots. Pig slurry and methanized pig slurry differentially impacted soil VOCs emissions: PS inputs doubled the C-VOC fluxes due to high emission of methanol while MPS inputs reduced VOCs fluxes even less than the control unamended plots, which is of great interest in the context of mitigating greenhouse gases in agriculture. Our results suggest that soil fluxes could, under certain conditions, not be marginal compared to plant fluxes and be potentially driven by new land-uses in agriculture. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue are the group of Raphaël Tripier and Nathalie Le Bris at the University of Brest (UMR CNRS 6521 CEMCA; France), Cathryn H. S. Driver from the South African Nuclear Energy Corporation in Pretoria (South Africa), and their collaborators. The image depicts the beginning of a new area of research into palladium and complexation of its radioisotopes for applications in nuclear medicine. Read the full text of the article at 10.1002/chem.202200942. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue are the group of Raphaël Tripier and Nathalie Le Bris at the University of Brest (UMR CNRS 6521 CEMCA; France), Cathryn H. S. Driver from the South African Nuclear Energy Corporation in Pretoria (South Africa), and their collaborators. The image depicts the beginning of a new area of research into palladium and complexation of its radioisotopes for applications in nuclear medicine. Read the full text of the article at10.1002/chem.202200942. [ABSTRACT FROM AUTHOR]

By showing that the monopicolinate cyclam B TE1PA b is a highly relevant chelator for natural and radioactive Pd, we have opened avenues to enrich the area of palladium-based targeted radiotherapies. Keywords: cyclam; cyclam monopicolinate; complexation; palladium(II); palladium-109; radiolabeling EN cyclam cyclam monopicolinate complexation palladium(II) palladium-109 radiolabeling 1 1 1 07/25/22 20220720 NES 220720 B The coordination chemistry of palladium b is poorly developed in nuclear medicine due to the lack of appropriate ligands capable of fulfilling all the criteria required for an in vivo application. [Extracted from the article]

Abstract: The ‘triazine’ methodology for the synthesis of functionalized bipyridine ligands proved to be a convenient method for the preparation of luminescent Eu(III) complexes. The approach allows flexible construction of chromophore and coordination sphere with control of photophysical properties. Europium(III) complexes [Eu1]–[Eu5] prepared in this way exhibit intense long-life metal-centered luminescence in aqueous media. The aromatic substituent in the position 5 of bipyridine has a significant influence on luminescence parameters and is used to introduce functionality for bioconjugation. The complexes [Eu4] and [Eu5] bearing primary amine groups are ready-to-go luminescent ‘tags’ for peptide labeling. [Copyright &y& Elsevier]

• The digested and the raw pig slurries had similar active microbial communities. • Biochemical composition of soil organic matter was less changed by digestate input. • Soil fungi were affected by the addition of slurries and especially raw pig slurry. • Specific emissions of soil volatile organic compounds according to the slurry input. • VOCs measurement is a promising approach in soil ecology. Production of biogas through anaerobic digestion of organic wastes should play an important role in sustainable development of energy supply, and the environmental effects of digestates have to be assessed. We investigated the effect of anaerobic digestion of pig slurry (PS) on the molecular quality of the digestate produced. The consequences of digested (DPS) and undigested PS use as organic soil fertilizer on soil microbial and biochemical properties and C-gas emissions (CO 2 and volatile organic compounds) were studied during a two-month incubation. PS and DPS differed in the amount of volatile organic compounds (VOCs) emitted, in their organic C and lignin contents but not in their active microbial composition. Application of both types of slurry to the soil immediately increased the content of soil dissolved organic carbon (DOC) compared to the control soil. The application of DPS induced few changes in the biochemical composition of soil organic matter compared to its raw material (PS) that increased the amount of phenolic compounds. After 60 days, both amended and control soils contained similar amounts of DOC, amended soils presenting a more diverse biochemical composition of their soil organic matter. Application of both slurries to soil triggered a succession of different active microbial communities, which could be attributed to the introduction of new microorganisms and the input of new labile organic carbon. Changes in fungal communities were stronger than those of bacteria and archaea; however, only slight differences were observed between the slurries. Different fluxes and emission dynamics of five VOCs (methanol, acetone, DMS, 2-pentanone and phenol) were observed during the incubation time following application of PS or DPS to soil while no differences in CO 2 emissions were observed. The present study calls for long-term field studies with VOC analyses as a promising tool to differentiate organic fertilization practices. [ABSTRACT FROM AUTHOR]