Triazolophanes that incorporate pyridyl subunits in place of phenylenes show a heightened propensity to form 2:1 sandwich complexes with halides. Persistent iodide-based sandwiches are observed. Binding constants confirm the inward-facing electron pairs on pyridyls destabilize 1:1 The (1)H NMR spectra verify have two pi-stacked triazolophanes rotated allow registration between opposite dipoles (directed inward) and triazoles outward). These dipolar interactions cooperate lower pyridyl-based...

Abstract Contrary to the simple expectations from Coulomb's law, Weinhold proposed that anions can stabilize each other as metastable dimers, yet experimental evidence for these species and their mutual stabilization is missing. We show two bisulfate form such which with self‐complementary hydrogen bonds, by encapsulation inside a pair of cyanostar macrocycles. The resulting 2:2 complex homodimer persists across all states matter, including in solution. dimer's OH⋅⋅⋅O bonding seen 1 H NMR...

The assembly of individual molecules into hierarchical structures is a promising strategy for developing three-dimensional materials with properties arising from interaction between the building blocks. Virus capsids are elegant examples biomolecular nanostructures, which themselves hierarchically assembled limited number protein subunits. Here, we demonstrate bio-inspired modular construction two levels hierarchy: formation catalytically active virus-like particles (VLPs) through directed...

We have probed the time evolution of a growing bacteria culture by extracting samples periodically and performing matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) on whole cells. The spectra generated this method contain tens peaks in 3−11-kDa range. Cultures E. coli strain K-12 were grown two types containers at nutrient concentrations sampled from 6 to 84 h after inoculation. relative intensities several stronger vary quite dramatically as function time. These...

Abstract Triazolophanes are used as the venue to compete an aliphatic propylene CH hydrogen‐bond donor against aromatic phenylene one. Longer CH ⋅⋅⋅ Cl − hydrogen bonds were calculated from location of chloride within propylene‐based triazolophane. The gas‐phase energetics binding (Δ G bind , Δ H S ) and configurational entropy config computed by taking all low‐energy conformations into account. Comparison between phenylene‐ triazolophanes shows free energy decreased =−194 −182 kJ mol −1...

In this paper, we report the influence of reaction conditions and chain length on nanoparticle (NP) size morphology for thermal decomposition long-chain iron carboxylates such as Fe(III) oleate, palmitate, myristate. majority cases, spherical NPs are obtained; however, nonspherical morphologies were observed in some "extreme" conditions. For example, oxide nanostars formed eicosane at Fe oleate/oleic acid ratio 0.49 g/mL: highest oleic content when still form. The cubic with flat facets...

Phosphate–phosphate oligomerization is shown to drive its recognition properties as revealed in co-assemblies with stackable macrocyclic hosts.

Significance Oncometabolites are small molecules that promote tumor formation and growth. L-2-hydroxyglutarate (L-2HG) is a putative oncometabolite associated with gliomas renal cell carcinomas, as well severe neurometabolic disorder known L-2-hydroxyglutaric aciduria. However, despite L-2HG commonly considered metabolic waste product, this compound was recently discovered to control immune fate, thereby demonstrating it has endogenous functions in healthy animal cells. Here, we find the...

Abstract The SeSe bond in an organo‐diselenide (RSeSeR, R is organic group) can break a 2e − reduction reaction, but it has limited capacity as cathode material for rechargeable lithium‐ion batteries. To increase its capacity, redox active species (e.g., sulfur) be added the middle of selenium atoms. Herein, phenyl diselenide (PDSe, PhSeSePh) mixed with sulfur to form two hybrid compounds 1:1 and 1:2 molar ratios, which almost double triple PDSe, respectively. Theoretical calculations...

The marine cyanobacterium Synechococcus is the second most abundant phytoplanktonic organism in world's oceans. ubiquity of this genus large part due to its use a diverse set photosynthetic light-harvesting pigments called phycobiliproteins, which allow it efficiently exploit wide range light colors. Here we uncover pivotal molecular mechanism underpinning widespread response among cells known as “type IV chromatic acclimation” (CA4). During process, pigmentation two main phycobiliproteins...

Sulfur-based cathodes are promising to enable high-energy-density lithium-sulfur batteries; however, elemental sulfur as active material faces several challenges, including undesirable volume change (∼80%) when completely reduced and high dependence on liquid electrolyte wherein an electrolyte/sulfur ratio >10 μL mg-1 is required for utilization. These limit the attainable energy densities of these batteries. Herein, we introduce a new class phenyl polysulfides C6H5S xC6H5 (4 ≤ x 6) cathode...

Tryptic digests of three proteins are reacted with O-methylisourea in order to convert lysine residues homoarginines. The resulting homoarginine-terminated peptides exhibit more intense MALDI mass spectral peaks than their lysine-terminated predecessors. This simple chemical reaction should therefore facilitate protein sequencing and mapping. Copyright © 2000 John Wiley & Sons, Ltd.

Natural products exhibit a broad range of biological properties and have been crucial source therapeutic agents novel scaffolds. Although bacterial secondary metabolomes are widely explored, they remain incompletely cataloged by current isolation characterization strategies. To identify metabolites residing in unexplored chemical space, we developed an integrated discovery approach that combines growth perturbation, accurate mass spectrometry, comparative spectra data analysis, fragmentation...

Structural rigidity is verified as a pre-organizational factor that acts together with the macrocyclic effect such synthesis helps in paying cost of bringing electropositive CH donors ready for H-bonding chloride.

Hydroxyanions pair up inside CH H-bonding cyanostar macrocycles against Coulombic repulsions and solvation forces acting to separate them. The driving responsible for assembly of bisulfate (HSO4- ) dimers are unclear. We investigated them using solvent quality tune the contributing we take advantage characteristic NMR signatures follow species distributions. show that apolar solvents enhance ion pairing stabilize formation a 2:2:2 complex composed π-stacked cyanostars encapsulating [HSO4...

Theory predicts that developmental plasticity, the capacity to change phenotypic trajectory during development, should evolve when environment varies sufficiently among generations, owing temporal (e.g., seasonal) variation or migration environments. We characterized levels of cellular plasticity development in populations Drosophila melanogaster experimentally evolved for over three years either constant temporally variable thermal used two measures lipid composition cell membranes as...

The tetrapyrroles haem, bacteriochlorophyll and cobalamin (B12 ) exhibit a complex interrelationship regarding their synthesis. In this study, we demonstrate that AerR functions as an antirepressor of the tetrapyrrole regulator CrtJ. We show purified contains B12 is bound to conserved histidine (His145) in AerR. interaction CrtJ was further demonstrated vitro by pull down experiments using bait quantified microscale thermophoresis. DNase I DNA footprint assays containing inhibits binding...

Nanopipettes are demonstrated as probes for local mass spectrometric analysis with potential small-scale extraction of analytes from single cells, tissue and organisms.

Significance Understanding how microbes adapt to novel environments is essential understanding acute bacterial infection and long-term disease, as genetic architecture underlying the production maintenance of variation influences a population’s potential for adaptation. In this in-depth analysis highly replicated Escherichia coli evolution experiment, we observe rapid diversification into stable subpopulations in response several environmental variables. This niche separation creates...

Significance The regulation of photosynthesis in marine phytoplankton, which account for approximately half the Earth’s primary productivity, is fundamentally important but not well understood. Picocyanobacteria such as Synechococcus , are responsible 10–20% global live environments where light availability often limits photosynthesis. CA4 a process commonly used by to optimize photon capture under conditions. We characterize demonstrating that two proteins, FciA and FciB (for type four...