An official website of the United States government
Abstract We report the synthesis and characterization of sulfated pillar[5]arene hosts (P5S2‐P5S10) that differ in the number of sulfate substituents. All fiveP5Snhosts display high solubility in water (73–131 mM) and do not undergo significant self‐association according to1H NMR dilution experiments. The x‐ray crystal structures ofP5S6,P5S6 ⋅ Me6HDA,P5S8 ⋅ Me6HDA, andP5S10 ⋅ Me6HDAreveal one intracavity molecule ofMe6HDAand several external molecules ofMe6HDAwhich form a network of close methonium ⋅ ⋅ ⋅ sulfate interactions. The thermodynamic parameters of complexation betweenP5Snand the panel of guests was measured by direct or competitive isothermal titration calorimetry. We find that the binding free energy toward a guest becomes more negative as the number of sulfate substituents increase. Conversely, the binding free energy of a specific sulfated pillar[5]arene toward a homologous series of guests becomes more negative as the number of NMe groups increases. The ability to tune the host ⋅ guest affinity by changing the number of sulfate substituents will be valuable in supramolecular polymers, separation materials, and latching applications.
more »
« less
Pillar[ n ]MaxQ: A New High Affinity Host Family for Sequestration in Water
Abstract We report the synthesis, X‐ray crystal structure, and molecular recognition properties of pillar[n]arene derivativeP[6]AS, which we refer to as Pillar[6]MaxQ along with analoguesP[5]ASandP[7]AStoward guests1–18. The ultratight binding affinity ofP[5]ASandP[6]AStoward quaternary (di)ammonium ions renders them prime candidates for in vitro and in vivo non‐covalent bioconjugation, for imaging and delivery applications, and as in vivo sequestration agents.
more »
« less
- Award ID(s):
- 1404911
- PAR ID:
- 10161858
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 32
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 13313-13319
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract We report that the direct macrocyclization of naphthalene monomers bearing ethyl ester functional groups delivers prism[5]arene derivatives, which can be deprotected to yield water‐soluble prism[5]arenes (H1andH3).1H NMR spectroscopy showed that dicationic guests bind with the hydrophobic cores buried inside the anisotropic magnetically shielding cavity. Isothermal titration calorimetry measurements showed thatH1andH3are high‐affinity hosts in PBS‐buffered water with Kavalues exceeding 109 M−1for a select guest. The complexation events are driven by the non‐classical hydrophobic effect, CH⋅⋅⋅π interactions, and electrostatic interactions. HostH1displays somewhat higher affinity toward a common guest than pillar[6]arene bearing carboxylic acid functional groups but is significantly less potent than pillar[6]arene bearing sulfate groups.H1andH3should be considered alongside other high affinity hosts for a variety of chemical and biological applications.more » « less
-
Abstract Orsay virus infection in the nematodeCaenorhabditis eleganspresents an opportunity to study host‐virus interactions in an easily culturable, whole‐animal host. Previously, a major limitation ofC. elegansas a model for studying antiviral immunity was the lack of viruses known to naturally infect the worm. With the 2011 discovery of the Orsay virus, a naturally occurring viral pathogen,C. eleganshas emerged as a compelling model for research on antiviral defense. From the perspective of the host, the genetic tractability ofC. elegansenables mechanistic studies of antiviral immunity while the transparency of this animal allows for the observation of subcellular processes in vivo. Preparing infective virus filtrate and performing infections can be achieved with relative ease in a laboratory setting. Moreover, several tools are available to measure the outcome of infection. Here, we describe workflows for generating infective virus filtrate, achieving reproducible infection ofC. elegans, and assessing the outcome of viral infection using molecular biology approaches and immunofluorescence. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of Orsay virus filtrate Support Protocol: SynchronizeC. elegansdevelopment by bleaching Basic Protocol 2: Orsay virus infection Basic Protocol 3: Quantification of Orsay virus RNA1/RNA2 transcript levels by qRT‐PCR Basic Protocol 4: Quantification of infection rate and fluorescence in situ hybridization (FISH) fluorescence intensity Basic Protocol 5: Immunofluorescent labeling of dsRNA in virus‐infected intestinal tissuemore » « less
-
In the centrosymmetric title complexes, di-μ-acetato-bis({N,N-dimethyl-2-[phenyl(pyridin-2-yl)methylidene]hydrazine-1-carbothioamidato}zinc(II)), [Zn2(C15H15N4S)2(C2H3O2)2] (I), and di-μ-acetato-bis({N-ethyl-2-[phenyl(pyridin-2-yl)methylidene]hydrazine-1-carbothioamidato}zinc(II)), [Zn2(C16H17N4S)2(C2H3O2)2] (II), the zinc ions are chelated by theN,N,S-tridentate ligands and bridged by pairs of acetate ions. The acetate ion in (I) is disordered over two orientations in a 0.756 (6):0.244 (6) ratio, leading to different zinc coordination modes for the major (5-coordinate) and minor (6-coordinate) disorder components. Geometrical indices [τ5= 0.32 and 0.30 for (I) (major component) and (II), respectively] suggest the zinc coordination in these phases to be distorted square pyramidal. This study forms part of our aim to discern the mechanism of metal binding in these chelators, their specificity and selectivity, and to gain insight into the role of cellular zinc in physiological processes such as infection, immunity and cancer.more » « less
-
Abstract Reactions of (O=)PH(OCH2CH3)2and BrMg(CH2)mCH=CH2(4.9–3.2 equiv;m=4 (a), 5 (b), 6 (c)) give the dialkylphosphine oxides (O=)PH[(CH2)mCH=CH2]2(2 a–c; 77–81 % after workup), which are treated with NaH and then α,ω‐dibromides Br(CH2)nBr (0.49–0.32 equiv;n=8 (a′), 10 (b′), 12 (c′), 14 (d′)) to yield the bis(trialkylphosphine oxides) [H2C=CH(CH2)m]2P(=O)(CH2)n(O=)P[(CH2)mCH=CH2]2(3 ab′,3 bc′,3 cd′,3 ca′; 79–84 %). Reactions of3 bc′and3 ca′with Grubbs’ first‐generation catalyst and then H2/PtO2afford the dibridgehead diphosphine dioxides(4 bc′,4 ca′; 14–19 %,n′=2m+2);31P NMR spectra show two stereoisomeric species (ca. 70:30). Crystal structures of two isomers of the latter are obtained,out,out‐4 ca′and a conformer ofin,out‐4 ca′that features crossed chains, such that the (O=)P vectors appearout,out. Whereas4 bc′resists crystallization, a byproduct derived from an alternative metathesis mode, (CH2)12P(=O)(CH2)12(O=)P(CH2)12, as well as3 ab′and3 bc′, are structurally characterized. The efficiencies of other routes to dibridgehead diphosphorus compounds are compared.more » « less
