We report the synthesis of the conformationally mobile S-shaped glycoluril pentamer building block and two new acyclic CB[n]-type receptors and . (9 mM) and (11 mM) have moderate aqueous solubility but their host•guest complexes are poorly soluble. Host does not undergo intermolecular self-association whereas does (K = 189±27 M).
View Article and Find Full Text PDFWe report the measurement of the binding constants (K) for cucurbit[n]uril (n = 7, 8) toward four series of guests based on 2,6-disubstituted adamantanes, 4,9-disubstituted diamantanes, 1,6-disubstituted diamantanes, and 1-substituted adamantane ammonium ions by direct and competitive H NMR spectroscopy. Compared to the affinity of CB[7]·Diam(NMe), the adamantane diammonium ion complexes (e.g.
View Article and Find Full Text PDFWe report the synthesis of which is a tetracationic analogue of our prototypical acyclic CB[n]-type molecular container . Both and possess excellent solubility in DO and do not undergo intermolecular self-association processes that would impinge on their molecular recognition properties. Compounds and do, however, undergo an intramolecular self-complexation process driven by ion-dipole interactions between the ureidyl C=O portals and the OCHCHNH arms along with inclusion of one aromatic wall in its own hydrophobic cavity.
View Article and Find Full Text PDFA training set of eleven X-ray structures determined for biomimetic complexes between cucurbit[n]uril (CB[7 or 8]) hosts and adamantane-/diamantane ammonium/aminium guests were studied with DFT-D3 quantum mechanical computational methods to afford ΔG binding energies. A novel feature of this work is that the fidelity of the BLYP-D3/def2-TZVPP choice of DFT functional was proven by comparison with more accurate methods. For the first time, the CB[n]⋅guest complex binding energy subcomponents [for example, ΔE , ΔE , ΔG , binding entropy (-TΔS), and induced fit E , E ] were calculated.
View Article and Find Full Text PDFThe use of multivalent carbohydrate compounds to block cell-surface lectin receptors is a promising strategy to inhibit the entry of pathogens into cells and could lead to the discovery of novel antiviral agents. One of the main problems with this approach, however, is that it is difficult to make compounds of an adequate size and multivalency to mimic natural systems such as viruses. Hexakis adducts of [60]fullerene are useful building blocks in this regard because they maintain a globular shape at the same time as allowing control over the size and multivalency.
View Article and Find Full Text PDFTwo acyclic cucurbit[n]uril (CB[n])-type molecular containers that differ in the length of the (CH2 )n linker (M2C2: n=2, M2C4: n=4) between their aromatic sidewalls and sulfonate solubilizing groups were prepared and studied. The inherent solubilities of M2C2 (68 mm) and M2C4 (196 mm) are higher than the analogue with a (CH2 )3 linker (M2, 14 mm) studied previously. (1) H NMR dilution experiments show that M2C2 and M2C4 do not self-associate in water, which enables their use as solubilizing excipients.
View Article and Find Full Text PDFThe synthesis of acyclic cucurbit[n]uril dendrimers G1-G3 that bear four dendrons on their aromatic sidewalls via thiolate S(N)2 chemistry is reported. G1-G3 are polycationic and can bind to pEGFP plasmid DNA as shown by dynamic light scattering (DLS), gel electrophoresis, and scanning electron microscopy (SEM). The gene delivery ability of G1-G3 is presented.
View Article and Find Full Text PDFInhibition of excessive Toll-like receptor 4 (TLR4) signaling is a therapeutic approach pursued for many inflammatory diseases. We report that Mannoside Glycolipid Conjugates (MGCs) selectively blocked TLR4-mediated activation of human monocytes and monocyte-derived dendritic cells (DCs) by lipopolysaccharide (LPS). They potently suppressed pro-inflammatory cytokine secretion and maturation of DCs exposed to LPS, leading to impaired T cell stimulation.
View Article and Find Full Text PDFWe report the synthesis of mono- and difunctionalized acyclic cucurbit[n]uril-type containers (1HA, 1HDA, 2HDA) which bear hexylammonium and hexanediammonium arms. The intra- and intermolecular assembly processes of 1HA, 1HDA, 2HDA as well as the ability of CB[n] to trigger allosteric host–guest binding toward guests 9–11 are presented.
View Article and Find Full Text PDFMannoside glycolipid conjugates are able to inhibit human immunodeficiency virus type 1 (HIV-1) trans-infection mediated by human dendritic cells (DCs). The conjugates are formed by three building blocks: a linear or branched mannose head, a hydrophilic linker, and a 24-carbon lipid chain. We have shown that, even as single molecules, these compounds efficiently target mannose-binding lectins, such as DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) important for HIV-1 transmission.
View Article and Find Full Text PDFThe reaction of readily available optically active Si-tethered tris(malonates) with C60 gave easily separable diastereoisomers differing by the absolute configuration of the inherently chiral addition pattern on the fullerene core. The absolute configuration of the e,e,e addition pattern has been unambiguously determined using X-ray crystal structure analysis.
View Article and Find Full Text PDFPolyplexes prepared from DNA and globular compact polycationic derivatives constructed around a fullerene hexakis-adduct core have shown remarkable gene delivery capabilities.
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