Porous metal-organic frameworks (MOFs) have been studied in the context of a wide variety of applications, particularly in relation to molecular storage and separation sciences. Recently, we reported a green, renewable framework material composed of γ-cyclodextrin (γ-CD) and alkali metal salts--namely, CD-MOF. This porous material has been shown to facilitate the separation of mixtures of alkylaromatic compounds, including the BTEX mixture (benzene, toluene, ethylbenzene, and the regioisomers of xylene), into their pure components, in both the liquid and gas phases, in an energy-efficient manner which could have implications for the petrochemical industry. Here, we report the ability of CD-MOF to separate a wide variety of mixtures, including ethylbenzene from styrene, haloaromatics, terpinenes, pinenes and other chiral compounds. CD-MOF retains saturated compounds to a greater extent than their unsaturated analogues. Also, the location of a double bond within a molecule influences its retention within the extended framework, as revealed in the case of the structural isomers of pinene and terpinine, where the isomers with exocyclic double bonds are more highly retained than those with endocyclic double bonds. The ability of CD-MOF to separate various mono- and disubstituted haloaromatic compounds appears to be controlled by both the size of the halogen substituents and the strength of the noncovalent bonding interactions between the analyte and the framework, an observation which has been confirmed by molecular simulations. Since CD-MOF is a homochiral framework, it is also able to resolve the enantiomers of chiral analytes, including those of limonene and 1-phenylethanol. These findings could lead to cheaper and easier-to-prepare stationary phases for HPLC separations when compared with other chiral stationary phases, such as CD-bonded silica particles.

Although ibuprofen is one of the most widely used nonsteroidal anti-inflammatory drugs (NSAIDs), it exhibits poor solubility in aqueous and physiological environments as a free acid. In order to improve its oral bioavailability and rate of uptake, extensive research into the development of new formulations of ibuprofen has been undertaken, including the use of excipients as well as ibuprofen salts, such as ibuprofen lysinate and ibuprofen, sodium salt. The ultimate goals of these studies are to reduce the time required for maximum uptake of ibuprofen, as this period of time is directly proportional to the rate of onset of analgesic/anti-inflammatory effects, and to increase the half-life of the drug within the body; that is, the duration of action of the effects of the drug. Herein, we present a pharmaceutical cocrystal of ibuprofen and the biocompatible metal-organic framework called CD-MOF. This metal-organic framework (MOF) is based upon γ-cyclodextrin (γ-CD) tori that are coordinated to alkali metal cations (e.g., K ions) on both their primary and secondary faces in an alternating manner to form a porous framework built up from (γ-CD) cubes. We show that ibuprofen can be incorporated within CD-MOF-1 either by (i) a crystallization process using the potassium salt of ibuprofen as the alkali cation source for production of the MOF or by (ii) absorption and deprotonation of the free-acid, leading to an uptake of 23-26 wt % of ibuprofen within the CD-MOF. In vitro viability studies revealed that the CD-MOF is inherently not affecting the viability of the cells with no IC value determined up to a concentration of 100 μM. Bioavailability investigations were conducted on mice, and the ibuprofen/CD-MOF pharmaceutical cocrystal was compared to control samples of the potassium salt of ibuprofen in the presence and absence of γ-CD. From these animal studies, we observed that the ibuprofen/CD-MOF-1 cocrystal exhibits the same rapid uptake of ibuprofen as the ibuprofen potassium salt control sample with a peak plasma concentration observed within 20 min, and the cocrystal has the added benefit of a 100% longer half-life in blood plasma samples and is intrinsically less hygroscopic than the pure salt form.

materials for lithium-ion batteries. [19][20][21] Despite the ease of their synthesis and the ability to tune their electronic properties, the neutral states of organic small molecules are often quite soluble in common battery electrolyte solvents, such as carbonates and ethers, resulting in fast capacity decay during cycling tests. [22][23][24][25][26][27][28] Polymerization of redox-active units minimizes their solubility, but usually requires the use of large amounts of electron-conducting additive-e.g., carbon black, graphene, or carbon nanotubes-to provide a continuous electronic pathway between the redox-active sites and the electrodes. [29][30][31] Most importantly, the measured rate capabilities of organic electrodes tend to be much lower than those of traditional inorganic ones, perhaps because they lack a rigid 3D nanoporous framework-a feature inherent to crystalline inorganic materials-to aid and abet the effi cient diffusion of Li + ions throughout the active layer to sustain the effectiveness of electrochemical reactions in the battery. [32][33][34] Recently, we reported [ 35 ] the preparation of the molecular triangular prism (−)-NDI-᭝ ( Figure 1 A) and its enantiomer (+)-NDI-᭝ from a single-step condensation of commercially available naphthalene dianhydride with ( RR )-and ( SS ) -trans -1,2-diaminocyclohexane, respectively. These thermally stable compounds ( Figure S1, Supporting Information) contain three redox-active naphthalenediimide (NDI) units in a rigid, cyclic constitution. Solution-state studies, together with DFT calculations, reveal through-space electron delocalization across the overlapping π-orbitals of the three NDI units as a consequence of their triangular constitution. As a result of this stable electronic coupling, a single molecule of (−)-or (+)-NDI-᭝ can store and release up to six electrons reversibly, yielding a theoretical capacity of 154.8 mAh g −1 . Furthermore, the (−)-and (+)-NDI-᭝ molecular triangles are only sparingly soluble in nonaqueous electrolyte solvents, leading us to believe that they would be highly attractive candidates to act as active materials for use in organic rechargeable lithium-ion batteries. In order to understand the structure-performance relationship of these triangles, we also prepared a monomeric NDI derivative NDI-Ref (Figure 1 B) as a control compound.We began our investigation by evaluating the performance of (−)-NDI -᭝ versus NDI-Ref as the active component within organic electrodes. Electrode slurries of each were prepared by mixing the desired active material with conductive carbon black and 10 wt% of polyvinylidene fl uoride (PVDF) binder in anhydrous N -methyl-2-pyrrolidone (NMP). From screening various organic electrode compositions (see the Supporting Information), we found that 50 wt% of (−)-NDI -᭝ active material was the highest content loading we could achieve that still Batteries, one of the most effi cient and convenient energy storage technologies, have powered a revolution in our daily lives for over a century now. The explorat...

Pseudomonas aeruginosa is a significant human pathogen, it possesses almost all of the known antimicrobial resistance mechanisms. Quorum sensing (QS) is an intercellular communication system that orchestrates bacterial virulence and its targeting is an effective approach to diminish its pathogenesis. Repurposing of drugs is an advantageous strategy, in this study we aimed to repurpose the anti-diabetic drugs sitagliptin, metformin and vildagliptin as anti-QS in P. aeruginosa. The effects of sub-inhibitory concentrations of the tested drugs on the expression of QS-encoding genes and QS-regulated virulence factors were assessed. The protective activity of tested drugs on P. aeruginosa pathogenesis was evaluated in vivo on mice. In silico analysis was performed to evaluate the interference capabilities of the tested drugs on QS-receptors. Although the three drugs reduced the expression of QS-encoding genes, only sitagliptin inhibited the P. aeruginosa virulence in vitro and protected mice from it. In contrast, metformin showed significant in vitro anti-QS activities but failed to protect mice from P. aeruginosa. Vildagliptin did not show any in vitro or in vivo efficacy. Sitagliptin is a promising anti-QS agent because of its chemical nature that hindered QS-receptors. Moreover, it gives an insight to consider their similar chemical structures as anti-QS agents or even design new chemically similar anti-QS pharmacophores.

Metal−organic frameworks (MOFs) are known to facilitate energy-efficient separations of important industrial chemical feedstocks. Here, we report how a class of green MOFsnamely CD-MOFsexhibits high shape selectivity toward aromatic hydrocarbons. CD-MOFs, which consist of an extended porous network of γ-cyclodextrins (γ-CDs) and alkali metal cations, can separate a wide range of benzenoid compounds as a result of their relative orientation and packing within the transverse channels formed from linking (γ-CD) 6 body-centered cuboids in three dimensions. Adsorption isotherms and liquid-phase chromatographic measurements indicate a retention order of ortho-> meta-> para-xylene. The persistence of this regioselectivity is also observed during the liquid-phase chromatography of the ethyltoluene and cymene regioisomers. In addition, molecular shape-sorting within CDMOFs facilitates the separation of the industrially relevant BTEX (benzene, toluene, ethylbenzene, and xylene isomers) mixture. The high resolution and large separation factors exhibited by CD-MOFs for benzene and these alkylaromatics provide an efficient, reliable, and green alternative to current isolation protocols. Furthermore, the isolation of the regioisomers of (i) ethyltoluene and (ii) cymene, together with the purification of (iii) cumene from its major impurities (benzene, n-propylbenzene, and diisopropylbenzene) highlight the specificity of the shape selectivity exhibited by CD-MOFs. Grand canonical Monte Carlo simulations and single component static vapor adsorption isotherms and kinetics reveal the origin of the shape selectivity and provide insight into the capability of CD-MOFs to serve as versatile separation platforms derived from renewable sources. ■ INTRODUCTIONWith the expanding global demand for petrochemical feedstocks, the development of novel, low-cost materials that reduce the impact of chemical processing on the environment is critically important. Improving the efficiency of the refinement and separation of aromatic hydrocarbons is of particular importance, given the large volumes on which these compounds are produced. The sustained interest in metal− organic frameworks 1 (MOFs) as adsorbents and sequestering agents for industrially important gases, 2−4 e.g., H 2 , CH 4 , CO 2 and N 2 , as well as for the liquid-phase separation of larger molecular compounds, which include (1) constitutional isomers, 5 (2) chiral compounds, 6 (3) aliphatic hydrocarbons, 3b,5b,7 and (4) pharmaceuticals, 8 is leading to MOFs being investigated as alternatives to zeolites 9 and activated carbon 10 as separation media. The improvements 5−7 in separation efficiencies using MOFs over traditional size-and shape-selective materials can be attributed primarily to (i) the physiochemical properties imbedded in their diverse building blocks, (ii) their higher surface areas, and (iii) their larger adsorption capacities, which reduce the amount of adsorbent required for industrial processes. 7a,11 Consequently, MOFs represent emergent materials f...