Highly Site-Selective Direct C-H Bond Functionalization of Unactivated Arenes with Propargyl α-Aryl-α-diazoacetates via Scandium Catalysis.

Highly chemo- and regio-selective C-H bond functionalization of unactivated arenes with propargyl α-aryl-α-diazoacetates has been developed using scandium catalysis. A variety of unactivated, mildly deactivated, and electronically activated arenes have been functionalized using this protocol. The synergistic combination of scandium triflate as a catalyst and propargyl α-aryl-α-diazoacetate as a reagent played a pivotal role in the effective C-H bond functionalization of arenes without the assistance of any directing group or ligand.

Characterization of heterologously expressed Fibril, a shape and motility determining cytoskeletal protein of the helical bacterium .

Fibril is a constitutive filament-forming cytoskeletal protein of unidentified fold, exclusive to members of genus . It is hypothesized to undergo conformational changes necessary to bring about motility through changes in cell helicity. However, the mechanism driving conformational changes in Fibril remains unknown.

Direct Access to Thiocyano-Thioesters from Cyclic Thioacetals via Photoredox Catalysis: An Introduction of Two Functional Groups in One Pot.

The cyanation of organic compounds is an important synthetic transformation and mainly relies on a toxic CN source. Undeniably, thiocyanate salt has emerged as a very mild and environmentally benign CN source, yet its synthetic utility for cyanation is highly limited to very few types of organic compounds. Herein, we report the direct cyanation of cyclic thioacetals for accessing compounds with two different functional groups (thiocyano-thioesters) in one pot using sodium thiocyanate via photoredox catalysis.

Site-Specific Fluorescent Labeling of the Cysteine-Rich Toxin, DkTx, for TRPV1 Ion Channel Imaging and Membrane Binding Studies.

Peptide toxins secreted by venomous animals bind to mammalian ion channel proteins and modulate their function. The high specificity of these toxins for their target ion channels enables them to serve as powerful tools for ion channel biology. Toxins labeled with fluorescent dyes are employed for the cellular imaging of channels and also for studying toxin-channel and toxin-membrane interactions.

Understanding the n → π* non-covalent interaction using different experimental and theoretical approaches.

Herein, a perspective on the recent understanding of weak n → π* interaction obtained using different experimental and theoretical approaches is presented. This interaction is purely an orbital interaction that involves the delocalization of the lone pair electrons (n) on nitrogen, oxygen, and sulfur to the π* orbitals of CO, CN, and aromatic rings. The n → π* interaction has been found to profoundly influence the stabilization of peptides, proteins, drugs, and various small molecules.

Metabolic Labeling-Based Chemoproteomics Establishes Choline Metabolites as Protein Function Modulators.

Choline is an essential nutrient for mammalian cells. Our understanding of the cellular functions of choline and its metabolites, independent of their roles as choline lipid metabolism intermediates, remains limited. In addition to fundamental cellular physiology, this knowledge has implications for cancer biology because elevated choline metabolite levels are a hallmark of cancer.

A multi-omics analysis reveals that the lysine deacetylase ABHD14B influences glucose metabolism in mammals.

The sirtuins and histone deacetylases are the best characterized members of the lysine deacetylase (KDAC) enzyme family. Recently, we annotated the "orphan" enzyme ABHD14B (α/β-hydrolase domain containing protein # 14B) as a novel KDAC and showed this enzyme's ability to transfer an acetyl-group from protein lysine residue(s) to coenzyme-A to yield acetyl-coenzyme-A, thereby, expanding the repertoire of this enzyme family. However, the role of ABHD14B in metabolic processes is not fully elucidated.

Tertiary-Butylbenzene Functionalization as a Strategy for β-Sheet Polypeptides.

β-Sheet forming polypeptides are one of the least explored synthetic systems due to their uncontrolled precipitation in the ring-opening polymerization (ROP) synthetic methodology. Here, a new -butylbenzene functionalization approach is introduced to overcome this limitation by sterically controlling the propagating polymer chains, and homogeneous polymerization with good control over chain growth was accomplished. New bulky -carboxyanhydride monomers were designed having -butylbenzene pendant by multistep organic synthesis, and N-heterocyclic carbene was explored as a catalyst to make high-molecular-weight and narrow polydisperse soluble polypeptides.

How Reproducible are Surface Areas Calculated from the BET Equation?

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials.

Unveiling the Impact of Diverse Morphology of Ionic Porous Organic Polymers with Mechanistic Insight on the Ultrafast and Selective Removal of Toxic Pollutants from Water.

In recent years, detoxification of contaminated water by different types of materials has received a great deal of attention. However, lack of methodical in-depth understanding of the role of various physical properties of such materials toward improved sorption performance limits their applicable efficiencies. In perspective, decontamination of oxoanion-polluted water by porous materials with different morphologies are unexplored due to a shortfall of proper synthetic strategies.

Correction: A hybrid blue perovskite@metal-organic gel (MOG) nanocomposite: simultaneous improvement of luminescence and stability.

[This corrects the article DOI: 10.1039/C9SC03829A.].

AUXIN RESPONSE FACTOR 16 (StARF16) regulates defense gene StNPR1 upon infection with necrotrophic pathogen in potato.

We demonstrate a new regulatory mechanism in the jasmonic acid (JA) and salicylic acid (SA) mediated crosstalk in potato defense response, wherein, miR160 target StARF16 (a gene involved in growth and development) binds to the promoter of StNPR1 (a defense gene) and negatively regulates its expression to suppress the SA pathway. Overall, our study establishes the importance of StARF16 in regulation of StNPR1 during JA mediated defense response upon necrotrophic pathogen interaction. Plants employ antagonistic crosstalk between salicylic acid (SA) and jasmonic acid (JA) to effectively defend them from pathogens.

Silver soldering of PNA:DNA duplexes: assembly of a triple duplex from bimodal PNAs with all-C on one face.

DNA:bm-PNA duplexes endowed with all-C on either the t-amide or triazole face and mixed base sequence on the other face can be welded with silver ions through C:Ag:C connects to give triple duplexes in one complex. The interplay of WC and Ag-mediated duplexes leads to synergistic stability effects on both duplexes and the complex.

Visible Light-Driven Highly Selective CO Reduction to CH Using Potassium-Doped g-CN.

Establishment of an efficient and robust artificial photocatalytic system to convert solar energy into chemical fuels through CO conversion is a cherished goal in the fields of clean energy and environmental protection. In this work, we have explored an emergent low- nitrogen-rich carbon nitride material g-CN (analogue of g-CN) for CO conversion under visible light illumination. A significant enhancement of the CH production rate was detected for g-CN in comparison to that of g-CN.

Unfolding the Role of Building Units of MOFs with Mechanistic Insight Towards Selective Metal Ions Detection in Water.

The potential emergence of fluorescence-based techniques has propelled research towards developing probes that can sense trace metal ions specifically. Although luminescent metal-organic frameworks (MOFs) are well suited for this application, the role of building blocks towards detection is not fully understood. In this work, a systematic screening by varying number of Lewis basic (pyridyl-N atoms) sites is carried out in a series of isostructural, robust UiO-67 MOFs, and targeting a model metal ion-Fe .

Bis(cholyl)-based chloride channels with oxalamide and hydrazide selectivity filters.

We report the development of supramolecular bis(cholyl) ion channels using oxalamide and hydrazide as selectivity filters. The hydrazide system showed superior chloride transport activity to oxalamide the formation of a barrel stave channel. The better chloride recognition within the hydrazide channel over the oxalalmide channel was confirmed from the theoretical calculations.

Quantitative Elasticity of Flexible Polymer Chains Using Interferometer-Based AFM.

We estimate the elasticity of single polymer chains using atomic force microscope (AFM)-based oscillatory experiments. An accurate estimate of elasticity using AFM is limited by assumptions in describing the dynamics of an oscillating cantilever. Here, we use a home-built fiber-interferometry-based detection system that allows a simple and universal point-mass description of cantilever oscillations.

Direct synthesis of 1,3-dithiolanes from terminal alkynes visible light photoredox catalysis.

A visible light-mediated, metal-free, regioselective dihydrothionation of terminal aromatic as well as heteroaromatic alkynes has been achieved using Eosin Y as a photoredox catalyst at room temperature. The protocol gives direct access to different 1,3-dithiolanes under neutral and mild reaction conditions without the use of any base or additives. The electron-donating, electron-withdrawing and electron-deactivating groups tolerated the photocatalytic reaction conditions.

Nanoparticle-Mediated Routing of Antibiotics into Mitochondria in Cancer Cells.

In recent years, antibiotics have emerged as alternative medicines in cancer therapy due to their capability of mitochondrial dysfunction in cancer cells. However, antibiotics render collateral damage in noncancerous cells by targeting mitochondrial transcription and translational machinery. To address this, herein, we have engineered three different mitochondria-targeted cationic antibiotic (tigecycline)-loaded nanoparticles from cholesterol conjugates.

Fluorescent ABC-Triblock Polymer Nanocarrier for Cisplatin Delivery to Cancer Cells.

Monitoring intracellular administration of non-luminescent anticancer drugs like cisplatin is a very challenging task in cancer research. Perylenebisimide (PBI) chromophore tagged fluorescent ABC-triblock polycaprolactone (PCL) nanoscaffold was engineered having carboxylic acid blocks for the chemical conjugation of cisplatin at the core and hydrophilic PEG blocks at the periphery. The amphiphilic ABC triblock Pt-prodrug was self-assembled into <200 nm nanoparticles and exhibited excellent shielding against drug detoxification by the glutathione (GSH) species in the cytosol.

Self-Reporting Polysaccharide Polymersome for Doxorubicin and Cisplatin Delivery to Live Cancer Cells.

We report self-reporting fluorescent polysaccharide polymersome nanoassemblies for enzyme-responsive intracellular delivery of two clinical anticancer drugs doxorubicin (DOX) and cisplatin to study the real-time drug-releasing aspects by fluorescent resonance energy transfer (FRET) bioimaging in live cancer cells. Fluorescent polymersomes were tailor-made by tagging an aggregation-induced emission (AIE) optical chromophore, tetraphenylethylene (TPE), and a plant-based vesicular directing hydrophobic unit through enzyme-biodegradable aliphatic ester chemical linkages in the polysaccharide dextran. The blue-luminescent polymersome self-assembled in water and exhibited excellent encapsulation capability for the red-luminescent anticancer drug DOX.

Selective and Sensitive Fluorescence Turn-On Detection of Cyanide Ions in Water by Post Metallization of a MOF.

Owing to detrimental impact of cyanide ion (CN ) towards the entire living system as well as its availability in drinking water, it has become very important developing potential sensory materials for the selective and sensitive recognition of CN ions in water. In the domain of sensory materials, luminescent metal-organic frameworks (LMOFs) have been considered as a promising candidate owing to their unique host-guest interaction, where MOFs can serve as an ideal scaffold for encapsulating relevant guest molecules rendering specific functionality. In this study, a post-synthetically modified MOF (viz.

Functional diversity of Himalayan bat communities declines at high elevation without the loss of phylogenetic diversity.

Species richness exhibits well-known patterns across elevational gradients in various taxa, but represents only one aspect of quantifying biodiversity patterns. Functional and phylogenetic diversity have received much less attention, particularly for vertebrate taxa. There is still a limited understanding of how functional, phylogenetic and taxonomic diversity change in concert across large gradients of elevation.

Post-synthetically modified metal-organic frameworks for sensing and capture of water pollutants.

Thanks to a bottom-up design of metals and organic ligands, the library of metal-organic frameworks (MOFs) has seen a conspicuous growth. Post-synthetically modified MOFs comprise a relatively smaller subset of this library. Whereas the approach of post-synthetic modification was seminally introduced for MOFs in the early 1990s, the earliest examples of post-synthetically modified MOFs are only congruous with adsorption and catalysis.

Development of aerial and belowground tubers in potato is governed by photoperiod and epigenetic mechanism.

Plants exhibit diverse developmental plasticity and modulate growth responses under various environmental conditions. Potato (Solanum tuberosum), a modified stem and an important food crop, serves as a substantial portion of the world's subsistence food supply. In the past two decades, crucial molecular signals have been identified that govern the tuberization (potato development) mechanism.