Designer Gelators for the Crystallization of a Salt Active Pharmaceutical Ingredient-Mexiletine Hydrochloride.

We report an approach to obtain drug-mimetic supramolecular gelators, which are capable of stabilizing metastable polymorphs of the pharmaceutical salt mexiletine hydrochloride, a highly polymorphic antiarrhythmic drug. Solution-phase screening led to the discovery of two new solvated solid forms of mexiletine, a type C 1,2,4-trichlorobenzene tetarto-solvate and a type D nitrobenzene solvate. Various metastable forms were crystallized within the gels under conditions which would not have been possible in solution.

Novel keto-enol tautomerism in 1,3,5-trihydroxybenzene systems.

We report a new synthesis of the water-soluble compound 1,3,5-trihydroxy-2,4,6-trimethylsulfonic acid (1), which exists in two tautomeric forms (60 : 40::enol%:keto%) and can be used as a proton conductor. Quantum chemical calculations show the importance of intramolecular hydrogen bonding and the presence of implicit MeOH solvent on the relative stabilities of the tautomers. 1 complexes with lanthanides through its sulfonato groups and forms a layered cage-like structure with one intramolecular and two intermolecular hydrogen bonds.

Indication of Quantitative Multiple Disease Resistance to Foliar Pathogens in in New Zealand.

Increasing resistance against foliar diseases is an important goal in the D.Don breeding program in New Zealand, and screening for resistance has been in place for some time, since the late 1960s. The current study presents results of four progeny trials within the breeding program to investigate whether multiple disease resistance could be detected against three different needle diseases in : needle blight (DNB) caused by , needle cast (CNC) caused by , and red needle cast (RNC) caused by Four progeny trials in the North Island of New Zealand were available to estimate heritabilities and between-trait genetic correlations.

Ball-free mechanochemistry: in situ real-time monitoring of pharmaceutical co-crystal formation by resonant acoustic mixing.

Resonant acoustic mixing (RAM) is a new technology designed for intensive mixing of powders that offers the capability to process powders with minimal damage to particles. This feature is particularly important for mixing impact-sensitive materials such as explosives and propellants. While the RAM technique has been extensively employed for the mixing of powders and viscous polymers, comparatively little is known about its use for mechanosynthesis.

Trimeric cyclamers: solution aggregation and high Z' crystals based on guest structure and basicity.

Ureidosalicylic acid forms remarkable trimeric cyclamer-like crystal structures with either three or six independent molecules in the asymmetric unit as a result of the excess of hydrogen bond donors and guest inclusion within the centre of the cyclamer. The structures persist in solution in hydrogen bond acceptor solvents suggesting a role for solution pre-association in forming high Z' structures.

Cavity-containing supramolecular gels as a crystallization tool for hydrophobic pharmaceuticals.

We present two approaches to low-molecular-weight supramolecular gels bearing hydrophobic cavities based on calixarene-containing building blocks. Gels are formed by a calixarene based tetrahydrazide gelator or a co-gel of a calixarene diammonium salt and a bis-crown ether. The calixarene hydrophobic cavity enables the complexation of hydrophobic drug molecules in a generic fashion thus providing an anchor site on the surface of the gel fibre to initiate drug crystal nucleation and growth.

Pharmaceutical crystallization with nanocellulose organogels.

Carboxylated nanocellulose forms organogels at 0.3 wt% in the presence of a cationic surfactant. The resulting gels can be used as novel crystallization media for pharmaceutical solid form control, resulting in isolation a new sulfapyridine solvate, morphology modification and crystallization of an octadecylammonium salt of sulfamethoxazole.

Manipulating three-dimensional gel network entanglement by thin film shearing.

Vortex fluidic mediated shearing of supramolecular gels in thin films leads to complete disruption of fluorous bis-urea derived gels. Hydrocarbon analogues however, are only partially disrupted, which emphasizes the resistance of non-fluorous bis-urea gelators towards shear. The gel structures have been studied by combining the thin film shearing with small angle neutron scattering.

Gelation by supramolecular dimerization of mono(urea)s.

Mono-ureido salicylic acid derivatives form hydrogen bonded dimers that mimic the gelation behaviour of covalently linked bis(urea)s. The 5-ureido salicylic acid isomers are much more effective gelators because of the lowered conjugation and less planar geometry, resulting in stronger urea···urea α-tape hydrogen bonding interactions.

Fluorescent carbon dot-molecular salt hydrogels.

The incorporation of functionalised carbon nanodots within a novel low molecular weight salt hydrogel derived from 5-aminosalicylic acid is reported. The carbon dots result in markedly enhanced gelation properties, while inclusion within the hydrophobic gel results in a dramatic fluorescence enhancement for the carbon nanomaterials. The resulting hybrid CD gels exhibit a useful sensor response for heavy metal ions, particularly Pb.

Correction: Fluorescent carbon dot-molecular salt hydrogels.

[This corrects the article DOI: 10.1039/C5SC01859E.].

Fluorous 'ponytails' lead to strong gelators showing thermally induced structure evolution.

Appending perfluoroalkyl substituents to bis(urea) gelators results in significantly decreased inter-chain interactions with markedly thinner fibres and hence more cross-linked and more transparent gels with potential applications in the crystallisation of fluorinated pharmaceuticals. Gel structure has been probed by detailed SANS measurements which indicate a surprising structure evolution on thermal cycling, not seen for hydrocarbon analogues. The SANS data are complemented by the single crystal X-ray structure of one fluorinated gelator.

A guide to prescribing anti-dementia medication.

This article outlines a good practice guide to prescribing anti-dementia medication developed jointly by a lead nurse for memory services and a clinical pharmacist. The guide brings together current evidence to produce a concise prescribing guideline for practitioners.

Structural alteration of the metal-organic pyrogallol[4]arene nano-capsule motif by incorporation of large metal centres.

Addition of cadmium(II) nitrate to gallium-coordinated metal-organic C-alkylpyrogallol[4]arene nano-capsules affords a variation of the near spherical hexamer motif, structural changes in which are induced by the markedly different nature of the secondary incorporated metal.

Introducing defects into metal-seamed nanocapsules using mixed macrocycles.

The synthesis and single-crystal X-ray diffraction structure of a dimeric zinc-seamed nanocapsule using a mixed pyrogallol/resorcinol[4]arene are presented. The use of "mixed" macrocycles results in an incomplete seam of coordination bonds around the nanocapsule's typically octa-metalated belt. The self-assembly of the nanocapsule occurs such that the single resorcinol moiety of each macrocycle aligns transversely.

A family of calix[4]arene-supported [Mn(III)2Mn(II)2] clusters.

In the cone conformation calix[4]arenes possess lower-rim polyphenolic pockets that are ideal for the complexation of various transition-metal centres. Reaction of these molecules with manganese salts in the presence of an appropriate base (and in some cases co-ligand) results in the formation of a family of calixarene-supported [Mn(III)(2)Mn(II)(2)] clusters that behave as single-molecule magnets (SMMs). Variation in the alkyl groups present at the upper-rim of the cone allows for the expression of a degree of control over the self-assembly of these SMM building blocks, whilst retaining the general magnetic properties.

Synovial chondromatosis of the elbow in a child.

Synovial chondromatosis is cartilaginous metaplasia of mesenchymal remnants of synovial tissue of the joints. Its main characteristic is the formation of cartilaginous nodules in the synovium and inside the articular space (loose bodies). It usually presents between the third and fifth decades and is rare in children.

[Mn(III)4Ln(III)4] calix[4]arene clusters as enhanced magnetic coolers and molecular magnets.

The use of methylene-bridged calix[4]arenes in 3d/4f chemistry produces a family of clusters of general formula [Mn(III)(4)Ln(III)(4)(OH)(4)(C4)(4)(NO(3))(2)(DMF)(6)(H(2)O)(6)](OH)(2) (where C4 = calix[4]arene; Ln = Gd (1), Tb (2), Dy (3)). The molecular structure describes a square of Ln(III) ions housed within a square of Mn(III) ions. Magnetic studies reveal that 1 has a large number of molecular spin states that are populated even at the lowest investigated temperatures, while the ferromagnetic limit S = 22 is being approached only at the highest applied fields.

Calixarene supported enneanuclear Cu(II) clusters.

New pseudo-trigonal planar supramolecular building blocks housing tri-capped trigonal prismatic [Cu(9)] clusters have been isolated from the facile reaction of Cu(II) salts with p-(t)But-calix[4]arene.

Versatile assembly of p-carboxylatocalix[4]arene-O-alkyl ethers.

Crystallisation of lower-rim tetra-O-alkylated p-carboxylatocalix[4]arenes from pyridine results in the formation of both bi-layer and pillar type supramolecular motifs. Full alkylation at the calixarene lower rim has significant influence over the supramolecular self-assembly motif, including preclusion of pyridine guest molecules from the calixarene cavity in the solid state.

Modulation of nanotube packing through the controlled self-assembly of tris-p-carboxylatocalix[4]arenes.

Crystallisation of tris-carboxylatocalix[4]arenes from pyridine affords self-assembled layered and triply helical nanotubular arrays; the latter of these represents a modulation of nanotubule spacing in a persistent self-assembly motif.