Reaction contest: hydrolysis intramolecular cyclisation reaction in alkyl squaramate esters.

The stability and hydrolytic behavior of squaramate esters in aqueous solutions have been investigated. The structure of squaramates and the nature of adjacent groups significantly influence their aqueous stability and reactivity towards nucleophiles. Squaramate esters, lacking or containing weakly basic neighboring group participation (NGP) substitutions, remain stable up to pH 9.

Sulfate-induced large amplitude conformational change in a Solomon link.

A doubly-interlocked [2]catenane - or Solomon link - undergoes a complex conformational change upon addition of sulfate in methanol. This transformation generates a single pocket where two SO anions bind through multiple hydrogen bonds and electrostatic interactions. Despite the close proximity of the two anions, binding is highly cooperative.

Stacking Interactions: A Supramolecular Approach to Upgrade Weak Halogen Bond Donors.

The co-crystallization of tetracyanobenzene (TCB) with haloarenes ArX provided six new co-crystals TCB ⋅ ArX (ArX=PhCl, PhBr, 4-MeC H Cl, 4-MeC H Br, 4-MeOC H Cl, 1,2-Br C H ) which were studied by X-ray diffraction. In these systems, the strong collective effect of π⋅⋅⋅π stacking interactions and lone pair-(X)⋅⋅⋅π-hole-(C) bondings between TCB and ArX promote the strength of X⋅⋅⋅N halogen bonding (HaB). Theoretical studies showed that the stacking interactions affect the σ-hole depth of the haloarenes, thus significantly boosting their ability to function as HaB donors.

Clinical Efficacy and Safety of Fanhdi, a Plasma-Derived VWF/Factor VIII Concentrate, in von Willebrand Disease in Spain: A Retrospective Study.

Objective: To evaluate the efficacy and safety of a plasma-derived factor VIII concentrate containing von Willebrand Factor (pdVWF/FVIII) in standard clinical practice in von Willebrand Disease (VWD) patients.

Methods: A retrospective, multicentric, observational study of VWD patients treated with Fanhdi, a pdVWF/FVIII concentrate, from January 2011 to December 2017 was conducted at 14 centers in Spain. Efficacy and safety were evaluated for acute bleeding episodes, for prevention of bleeding in surgeries, and for secondary long-term prophylaxis.

Anion-π Catalysis Enabled by the Mechanical Bond.

We report a series of rotaxane-based anion-π catalysts in which the mechanical bond between a bipyridine macrocycle and an axle containing an NDI unit is intrinsic to the activity observed, including a [3]rotaxane that catalyses an otherwise disfavoured Michael addition in >60 fold selectivity over a competing decarboxylation pathway that dominates under Brønsted base conditions. The results are rationalized by detailed experimental investigations, electrochemical and computational analysis.

Host-guest complexes supramolecular polymers in chalcogen bonding receptors: an experimental and theoretical study.

We describe here a comparative study between two tripodal anion receptors based on selenophene as the binding motif. The receptors use benzene or perfluorobenzene as a spacer. The presence of the electron-withdrawing ring activates the selenium atom for anion recognition inducing the formation of self-assembled supramolecular structures in the presence of chloride or bromide anions, which are bonded by the cooperative action of hydrogen and chalcogen bonding interactions.

Se⋅⋅⋅O/S and S⋅⋅⋅O Chalcogen Bonds in Small Molecules and Proteins: A Combined CSD and PDB Study.

The importance of selenium-centered noncovalent chalcogen bonds represented as Se⋅⋅⋅A (A=O/S) has been explored for short directional contacts in small molecules and proteins. In addition, S⋅⋅⋅O centered contacts have been analyzed. Computational analyses involving the quantitative assessment of the associated energetics, the molecular electrostatic potentials (MEP), and electron density derived topological parameters, namely, quantum theory of atom in molecules (QTAIM) analyses, and NBO (natural bond orbital) based calculations, have been performed to unequivocally establish the strength, stability, and attractive role of chalcogen bonds in the solid-state.

Diastereoselective Amplification of a Mechanically Chiral [2]Catenane.

Achiral [2]catenanes composed of rings with inequivalent sides may adopt chiral co-conformations. Their stereochemistry depends on the relative orientation of the interlocked rings and can be controlled by sterics or an external stimulus (e.g.

Pnictogen-bonding catalysis: brevetoxin-type polyether cyclizations.

Pnictogen-bond donors are attractive for use in catalysis because of deep σ holes, high multivalency, rich hypervalency, and chiral binding pockets. We here report natural product inspired epoxide-opening polyether cyclizations catalyzed by fluoroarylated Sb(v) > Sb(iii) > Bi > Sn > Ge. The distinctive characteristic found for pnictogen-bonding catalysis is the breaking of the Baldwin rules, that is selective cyclization into the -fused ladder oligomers known from the brevetoxins.

Unravelling the electronic nature of C-FO-C non-covalent interaction in proteins and small molecules in the solid state.

The participation of organic fluorine as a halogen bond donor is rare and is sensitive to the electronic environment in the vicinity of the fluorine atom. The enhancement in the electropositive character (the σ-hole formalism) in fluorine is established by the presence of electron withdrawing groups and this has been examined in the solid-state structures in small molecules and proteins. Short, directional FO contacts have been observed and physical insights obtained, from quantum mechanical calculations, via the molecular electrostatic potential, an analysis of their topological features from atoms-in-molecules, and donor-acceptor characteristics from natural bond orbital analyses.

Adherence to prophylaxis in adult patients with severe haemophilia A.

Introduction: Adherence is a cornerstone of factor VIII prophylactic treatment. Information regarding the factors with potential influence on adherence is limited, particularly in adult patients.

Aim: To assess adherence in adult patients with severe haemophilia A receiving prophylactic treatment in a real-life setting, and investigate the factors influencing adherence.

Radicalradical chalcogen bonds: CSD analysis and DFT calculations.

This manuscript reports a combination of crystallographic analysis (Cambridge Structural Database) and theoretical DFT calculations in chalcogen bonding interactions involving radicals in both the Ch bond (ChB) donor and acceptor. As a radical ChB acceptor (nucleophile) we have used benzodithiazolyl radical (BDTA) and as Ch bond donors (electrophile) we have used dithiadiazolyl and diselenadiazolyl radicals of the general formula p-X-C6F4-CNChChN (Ch = S, and Se). We have evaluated how the para substituent (X) affects the interaction energy, spin density and charge/spin transfer from the electron rich BDTA radical to the electron poor dichalcogenadiazolyl ring.

Anion Recognition by Neutral Chalcogen Bonding Receptors: Experimental and Theoretical Investigation.

Invited for the cover of this issue are the groups of Antonio Frontera at the Universitat de les Illes Balears and Antonio Caballero at the Universidad de Murcia. The image depicts one of the tellurophene based receptors described in this work. Read the full text of the article at 10.

Anion Recognition by Neutral Chalcogen Bonding Receptors: Experimental and Theoretical Investigations.

The utilization of neutral receptors for the molecular recognition of anions based on chalcogen bonding (ChB) is an undeveloped area of host-guest chemistry. In this manuscript, the synthesis of two new families of sulfur, selenium, and tellurium-based ChB binding motifs are reported. The stability of the thiophene, selenophene, and tellurophene binding motifs has enabled the determination of the association constants for ChB halide anion binding in the polar aprotic solvent THF by H, Se, and Te NMR experiments.

Charge-Assisted Chalcogen Bonds: CSD and DFT Analyses and Biological Implication in Glucosidase Inhibitors.

This study reports a combined Cambridge Structural Database and theoretical DFT study of charge assisted chalcogen bonds involving sulfonium, selenonium, and telluronium cations. The chalcogen bond has been recently defined by IUPAC as the net attractive interaction between an electrophilic region associated with a chalcogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. Divalent chalcogen atoms typically have up to two σ-holes and forms up to two ChBs; the same holds for tetravalent chalcogens which adopt a seesaw arrangement.

Surface Modification of Pseudoboehmite-Coated Aluminum Plates with Squaramic Acid Amphiphiles.

The functionalization of interfaces has become very important for the protection or modification of metal (metal oxides) surfaces. The functionalization of aluminum is particularly interesting because of its relevance in fabricating components for electronic devices. In this work, the utilization of squaramic acids for the functionalization of aluminum substrates is reported for the first time.

Nitropyridine-1-Oxides as Excellent π-Hole Donors: Interplay between σ-Hole (Halogen, Hydrogen, Triel, and Coordination Bonds) and π-Hole Interactions.

In this manuscript, we use the primary source of geometrical information, i.e., Cambridge Structural Database (CSD), combined with density functional theory (DFT) calculations (PBE0-D3/def2-TZVP level of theory) to demonstrate the relevance of π-hole interactions in para-nitro substituted pyridine-1-oxides.

Theoretical ab Initio Study on Cooperativity Effects between Nitro π-hole and Halogen Bonding Interactions.

This article analyzes the interplay between nitro's π-hole and halogen-bonding (XB) interactions in nitroarenes. Remarkable cooperativity effects are observed when π-hole and XB interactions coexist in the same complex. The nitroarene presents two π-holes, one approximately over the N atom of the nitro group and the other over the aromatic ring, being the former more positive.

Adherence to prophylaxis and quality of life in children and adolescents with severe haemophilia A.

Treatment adherence in adolescents with chronic diseases is around 50%, and failure is more common in preventive therapy. In haemophilia, contradictory results are reported by the published studies. The objective of this study was to evaluate adherence with factor VIII (FVIII) prophylaxis in Spanish patients with severe haemophilia A between age 6 and 20 years.

Rapid triplex asymmetric real-time PCR hybridization probe assay for the joint genotyping of F2, F5 and F12.

Introduction: The Factor 5 Leiden mutation and the G20210A variant of Factor 2 are two important risk factors for hereditary thromboembolism. Several reports have demonstrated that homozygous carriers for C46T mutation of the Factor 12 gene is associated with a significant increased risk for the development of coronary disease as well as cerebral and peripheral venous thrombosis.

Design And Methods: We develop a rapid and feasible asymmetric multiplex real-time PCR-based method using fluorescence resonance emission transfer (FRET) probes followed by a melting temperature (T(m)) curve assay for the simultaneous clinical diagnosis of F2, F5 and F12 mutations in a 10 microl closed tube.

Pathogenic study of anti-CD20 infusion-related severe refractory shock in diffuse large B-cell lymphoma.

Although rituximab is an effective and safe therapy for B-cell lymphoid malignancies, a few cases of severe infusion-related reactions have been reported. Severe refractory distributive shock is an infrequent side-effect of treatment with rituximab and, to our knowledge, there are no reports describing its pathogenesis in a case of fatal outcome in detail. We present for the first time a case of fatal rituximab infusion-related refractory distributive shock in a patient with CD5+ diffuse large B-cell lymphoma (DLBCL) and analyse the pathogenic mechanisms involved.

Gemcitabine and oxaliplatinum: an effective regimen in a patient with progressive refractory mantle cell lymphoma.

We report here a 68-year-old man with progressive refractory Mantle cell Lymphoma stage IV-A, treated with different chemotherapeutic drugs. With no therapeutic options we decided to treat him with oxaliplatinum-gemcitabine regimen, based on the proven efficacy and synergy of these drugs in other tumors and lymphomas. Treatment was well tolerated and patient achieved a maintained complete remission with 6 months of follow up.