An Amino Acid-Appended Naphthalene Bisimide-Based Bolaamphiphile- Selective Sensing of Chaotropic Anions by Thixotropic Hydrogelations.

An amino acid-based fluorophore probe, L-tryptophan appended naphthalene di-imide (NDI-W) forms stable hydrogels selectively in the presence of chaotropic anions (SCN, ClO , I, and NO ), borderline anion (Br) and F in 50 mM phosphate buffer of pH 8. NDI-W did not form stable hydrogels in 50 mM phosphate buffer of pH 8 in the presence of kosmotropic anions (SO , SO , CHCOO, and citrate) at the same conditions. However, gel-like assemblies for NDI-W in presence of SO , SO , CHCOO, IO , HSO , HCO , and NO anions and precipitate formation in the presence of HPO , HSO , and citric acid in 50 mM phosphate buffer of pH 8 have been observed.

1-Naphthylacetic acid appended amino acids-based hydrogels: probing of the supramolecular catalysis of ester hydrolysis reaction.

A 1-naphthaleneacetic acid-appended phenylalanine-derivative (Nap-F) forms a stable hydrogel with a minimum gelation concentration (MGC) of 0.7% w/v (21 mM) in phosphate buffer of pH 7.4.

A promising antifungal lipopeptide from Bacillus subtilis: its characterization and insight into the mode of action.

Emerging resistance of fungal pathogens and challenges faced in drug development have prompted renewed investigations into novel antifungal lipopeptides. The antifungal lipopeptide AF reported here is a natural lipopeptide isolated and purified from Bacillus subtilis. The AF lipopeptide's secondary structure, functional groups, and the presence of amino acid residues typical of lipopeptides were determined by circular dichroism, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy.

Myco-synthesis of multi-twinned silver nanoparticles as potential antibacterial and antimalarial agents.

In recent days, biogenic and green approaches for synthesizing nanostructures have gained much attention in biological and biomedical applications. Endophytic fungi have been recognized to produce several important biomolecules for use in various fields. The present work describes the use of endophytic fungi isolated from for the synthesis of multi-twinned silver nanoparticles (MT-AgNPs) and their successful applications in antimicrobial and antimalarial studies.

Simple high-precision diode laser system with digital control.

A simple wavelength tunable diode laser system has been designed and fabricated for laboratory use. Both the current and temperature controllers are based on an AVR microcontroller, and the experimental controls have been implemented with the help of daemon programs running in a message passing interface environment, which allows the users to run the control server and client programs on separate computers. The stability of the controllers has been tested using a distributed feedback (DFB) diode laser with a central wavelength of 852.

Expedient Ni-catalyzed C-H/C-H cross-dehydrogenative coupling of aryl amides with azoles.

A nickel-catalyzed C-H heteroarylation of arenes has been described using a removable oxazoline-aniline derived directing group. Utilization of an inexpensive nickel(II)-catalyst, substrate scope, functional group diversity and late-stage functionalization of xanthine-derived commercial drugs are the important practical features.

Pd-catalyzed bidentate auxiliary assisted remote C(sp)-H functionalization.

Pd-catalyzed C-H functionalisation affords effective synthetic tools to construct C-C and C-X bonds. Despite the challenges, the distal functionalization of C(sp)-H bonds has witnessed significant developments and the use of bidentate auxiliaries has garnished this area by providing an opportunity to control reactivity as well as selectivity beyond proximal sites. This article covers the recent developments on the Pd-catalyzed bidentate auxiliary-assisted distal C(sp)-H functionalization and is categorized based on the nature of functionalizations.

Mechanism of Side Chain-Controlled Proton Conductivity in Bioinspired Peptidic Nanostructures.

Bioinspired peptide assemblies are promising candidates for use as proton-conducting materials in electrochemical devices and other advanced technologies. Progress toward applications requires establishing foundational structure-function relationships for transport in these materials. This experimental-theoretical study sheds light on how the molecular structure and proton conduction are linked in three synthetic cyclic peptide nanotube assemblies that comprise the three canonical basic amino acids (lysine, arginine, and histidine).

Optimization of the performance of a voltage measuring station using genetic algorithm.

This article describes the use of the genetic algorithm (GA) for the optimization of the performance of a voltage measuring station. This procedure can be used for the instruments for which regular and systematic calibration is required for better performance. Here, a GA-based correction module has been used to internally store a few previous measured-value and measured-time pairs and to use these values to correct the current readings.

Evaluation of nested PCR and loop mediated isothermal amplification assay (LAMP) targeting 47 ​kDa gene of Orientia tsutsugamushi for diagnosis of scrub typhus.

Purpose: Diagnostic testing, in particular early detection, is critical for scrub typhus, as most infected individuals have nonspecific symptoms that are easily confused with dengue and malaria. PCR and LAMP offer an alternative DNA amplification method for detection of Orientia tsutsugamushi. Detection of Orientia tsutsugamushi DNA by targeting the 47-kDa gene using nested PCR and LAMP for diagnosis of scrub typhus.

Supramolecular Antiparallel β-Sheet Formation by Tetrapeptides Based on Amyloid Sequence.

Self-assembly of short peptides has emerged as an interesting research field for a wide range of applications. Recently, several truncated fragments of long-chain peptides or proteins responsible for different neurodegenerative diseases were studied to understand whether they can mimic the property and function of native peptides or not. It was reported that such a kind of peptide adopts a β-sheet structure in the disease state.

Pd-Catalyzed sp C-H alkoxycarbonylation of 8-methylquinolines using Mo(CO) as a CO surrogate.

A Pd(ii)-catalyzed three-component sp C-H alkoxycarbonylation of 8-methylquinonlines (8-MQs) with alcohols is accomplished using the colorless crystalline Mo(CO) as a CO source. The protocol is compatible with a wide range of 8-MQs and alcohols, furnishing the carbonylated adducts in moderate to good yields. The substrate scope, functional group tolerance and natural product mutation are the important practical features.

Oxidative C-H/N-H Annulation of Aromatic Amides with Dialkyl Malonates: Access to Isoindolinones and Dihydrobenzoindoles.

A copper-mediated oxidative C-H/N-H annulation of aromatic amides with dialkyl malonates has been presented to afford synthetically valuable dihydrobenzoindoles and isoindolinones. The reaction proceeds through direct oxidative C(sp)-H/C(sp)-H coupling followed by an intramolecular N-H/C(sp)-H dehydrogenative coupling to deliver the target motifs with broad scope and functional group tolerance.

Direct cyanidation of silver sulfide by heterolytic C-CN bond cleavage of acetonitrile.

Extraction of silver as silver cyanide from silver sulfide was made possible using acetonitrile as the source of cyanide. The process of cyanidation took place through the oxidation of sulfide to sulfur oxides and cleavage of the C-CN bond of acetonitrile. The reaction was found to be catalyzed by vanadium pentoxide and hydrogen peroxide.

Expedient iron-catalyzed stereospecific synthesis of triazines via cycloaddition of aziridines with diaziridines.

Iron-catalyzed stereospecific [3+3]-annulation of aziridines with diaziridines is described to furnish [1,2,4]-triazines in high yield at room temperature. The use of an inexpensive iron salt catalyst, substrate scope and enantiomeric purity are the important practical features.

Supramolecular Hydrogel from an Oxidized Byproduct of Tyrosine.

Herein we report for the first time the supramolecular hydrogelation of a derivative of 3-nitrotyrosine (), which is an oxidized byproduct of tyrosine, produced in the presence of reactive nitrogen species in the cell. The 9-fluorenylmethyloxycarbonyl (Fmoc) derivative of , , can form self-supported hydrogels at a wide range of pH values (4.5-8.

Self-Assembled Peptide Nanotube Films with High Proton Conductivity.

Design flexibility and modularity have emerged as powerful tools in the development of functional self-assembled peptide nanostructures. In particular, the tendency of peptides to form fibrils and nanotubes has motivated the investigation of electron and, more recently, proton transport in their fibrous films. In this study, we present a detailed characterization by impedance spectroscopy of films of self-assembled cyclic octa-d,l-α-peptide self-assembled nanotubes with amine side chains that promote proton transport.

Iron-Catalyzed Regioselective Remote C(sp)-H Carboxylation of Naphthyl and Quinoline Amides.

Iron(III)-catalyzed regioselective direct remote C-H carboxylation of naphthyl and quinoline amides was developed using CBr and alcohol. The reaction involves a radical pathway using a coordination activation strategy and single electron transfer process. The use of sustainable iron catalysis, selectivity, and the substrate scope are the important practical features.

Rh-Catalyzed tandem C-C/C-N bond formation of quinoxalines with alkynes leading to heterocyclic ammonium salts.

An efficient Rh-catalyzed oxidative C-H activation/annulation of 2-arylquinoxalines with internal alkynes is described using Cu(OAc)2·H2O and AgBF4 to afford a diverse variety of substituted quarternary ammonium salts at room temperature. The mechanism of the protocol is established on the basis of isolation of the 5-membered rhodacycle intermediate and kinetic isotope studies. The mild reaction conditions, substrate scope and functional group diversity are the salient practical features.

Correction: Copper-mediated regioselective C-H etherification of naphthylamides with arylboronic acids using water as an oxygen source.

Correction for 'Copper-mediated regioselective C-H etherification of naphthylamides with arylboronic acids using water as an oxygen source' by Subhasish Roy et al., Chem. Commun.

Copper-mediated regioselective C-H etherification of naphthylamides with arylboronic acids using water as an oxygen source.

The copper-mediated regioselective C-H activation and C-O bond formation of naphthylamides with arylboronic acids has been developed using water as an oxygen source. The kinetic isotope study suggests that C-H bond activation is the rate-determining step. The H2O18 labelling experiment reveals the incorporation of oxygen from water.

Measuring Proton Currents of Bioinspired Materials with Metallic Contacts.

Charge transfer at the interface between the active layer and the contact is essential in any device. Transfer of electronic charges across the contact/active layer interface with metal contacts is well-understood. To this end, noble metals, such as gold or platinum, are widely used.

Size specific emission in peptide capped gold quantum clusters with tunable photoswitching behavior.

Three different types of fluorescent gold clusters (namely blue, green and red emitting) have been prepared from a gold precursor (chloroauric acid) under moderate conditions in aqueous medium. A cysteine containing dipeptide has been used for the formation of these quantum clusters as this peptide molecule contains a thiol group in the side chain to cap these nascently formed clusters and the free amino and carboxylic moieties assist in water solubility. Thus, the clusters are also environmentally friendly as the capped peptide is made up of only naturally occurring protein amino acids.

A dipeptide-based superhydrogel: Removal of toxic dyes and heavy metal ions from waste water.

A short peptide-based molecule has been found to form a strong hydrogel at phosphate buffer solution of pH 7.46. The hydrogel has been characterized thoroughly using various techniques including field emission scanning electron microscopy (FE-SEM), wide angle powder X-ray diffraction (PXRD), and rheological analysis.

A Metal-Free Protocol for Aminofunctionalization of Olefins Using TsNBr2.

N,N-Dibromo-p-toluene sulfonamide (TsNBr2) has been found to be an effective reagent for various aminofunctionalization reactions. This reagent behaves both as an electrophilic bromine source as well as amine to react with olefins under different conditions to yield aminoether, imidazoline, diamine and amino bromine. The reaction proceeds rapidly under mild conditions with high regioselectivity.