Cross Redox Coupling of Aryl-Aldehydes and p-Benzoquinone.

Herein, we report an unprecedented Cross Redox Coupling (CRC) reaction catalyzed by Cu(OAc)2·H2O. As a proof-of-concept, direct coupling of aromatic aldehydes (or alcohols) and p-benzoquinone led to an ester in the presence of the Cu(II)-TBHP combination. During the coupling process, the C-H bond of the aldehydes was converted directly to a C-O bond.

Decanuclear Ln10 Wheels and Vertex-Shared Spirocyclic Ln5 Cores: Synthesis, Structure, SMM Behavior, and MCE Properties.

The reaction of a Schiff base ligand (LH3) with lanthanide salts, pivalic acid and triethylamine in 1:1:1:3 and 4:5:8:20 stoichiometric ratios results in the formation of decanuclear Ln10 (Ln = Dy (1), Tb (2), and Gd (3)) and pentanuclear Ln5 complexes (Ln = Gd (4), Tb (5), and Dy (6)), respectively. The formation of Ln10 and Ln5 complexes are fully governed by the stoichiometry of the reagents used. Detailed magnetic studies on these complexes (1-6) have been carried out.

Critical Assessment of the Strength of Hydrogen Bonds between the Sulfur Atom of Methionine/Cysteine and Backbone Amides in Proteins.

Gas-phase vibrational spectroscopy, coupled cluster (CCSD(T)), and dispersion corrected density functional (B97-D3) methods are employed to characterize surprisingly strong sulfur center H-bonded (SCHB) complexes between cis and trans amide NH and S atom of methionine and cysteine side chain. The amide N-H···S H-bonds are compared with the representative classical σ- and π-type H-bonded complexes such as N-H···O, N-H···O═C and N-H···π H-bonds. With the spectroscopic, theoretical, and structural evidence, amide N-H···S H-bonds are found to be as strong as the classical σ-type H-bonds, despite the smaller electronegativity of sulfur in comparison to oxygen.

Instability of Amide Bond Comprising the 2-Aminotropone Moiety: Cleavable under Mild Acidic Conditions.

An unusual hydrolysis/solvolysis of the classical acyclic amide bond, derived from N-troponylaminoethylglycine (Traeg) and α-amino acids, is described under mild acidic conditions. The reactivity of this amide bond is possibly owed to the protonation of the troponyl carbonyl functional group. The results suggest that the Traeg amino acid is a potential candidate for protecting and caging of the amine functional group of bioactive molecules via a cleavable amide bond.

Structurally Flexible C₃-Symmetric Receptors for Molecular Recognition and Their Self-Assembly Properties.

The bioinspired design and synthesis of building blocks and their assemblies by the supramolecular approach has ever fascinated scientists to utilize such artificial systems for numerous purposes. Flexibility is a basic feature of natural systems. However, in artificial systems this is difficult to control, especially if there is no preorganization of the component(s) of a system.

Tradition in treating taboo: Folkloric medicinal wisdom of the aboriginals of Purulia district, West Bengal, India against sexual, gynaecological and related disorders.

Ethnopharmacological Relevance: In order to explore the traditional medicine practised by the ethnic communities residing in the topographically and climatically challenged Purulia, an underprivileged district of West Bengal, India, a quantitative ethnobiological approach was adopted to document the folkloric use of ethnomedicinals against different sexual, gynaecological and related ailments.

Materials And Methods: Ethnobiological surveys were conducted during 2012-2015 by interviewing 82 informants or traditional healers with the help of a semi-structured questionnaire. The survey included questions on botanical and non-botanical ingredients and additives mixed with monoherbal and polyherbal formulations, vernacular names of the plants and animals, methods of preparation and administration and restrictions during medications.

Sialic acids: biomarkers in endocrinal cancers.

Sialylations are post translational modification of proteins and lipids that play important role in recognition, signaling, immunological response and cell-cell interaction. Improper sialylations due to altered sialyl transferases, sialidases, gene structure and expression, sialic acid metabolism however lead to diseases and thus sialic acids form an important biomarker in disease. In the endocrinal biology such improper sialylations including altered expression of sialylated moieties have been shown to be associated with disorders.

Solvent-free ball-milling subcomponent synthesis of metallosupramolecular complexes.

Subcomponent self-assembly from components A, B, C, D, and Fe(2+) under solvent-free conditions by self-sorting leads to the construction of three structurally different metallosupramolecular iron(II) complexes. Under carefully selected ball-milling conditions, tetranuclear [Fe4 (AD2 )6 ](4-) 22-component cage 1, dinuclear [Fe2 (BD2 )3 ](2-) 11-component helicate 2, and 5-component mononuclear [Fe(CD3 )](2+) complex 3 were prepared simultaneously in a one-pot reaction from 38 components. Through subcomponent substitution reaction by adding subcomponent B, the [Fe4 (AD2 )6 ](4-) cage converts quantitatively to the [Fe2 (BD2 )3 ](2-) helicate, which, in turn, upon addition of subcomponent C, transforms to [Fe(CD3 )](2+) , following the hierarchical preference based on the thermodynamic stability of the complexes.

Radical-Induced Metal and Solvent-Free Cross-Coupling Using TBAI-TBHP: Oxidative Amidation of Aldehydes and Alcohols with N-Chloramines via C-H Activation.

A solvent-free cross-coupling method for oxidative amidation of aldehydes and alcohols via a metal-free radial pathway has been demonstrated. The proposed methodology uses the TBAI-TBHP combination which efficiently induces metal-free C-H activation of aldehydes under neat conditions at 50 °C or ball-milling conditions at room temperature.

Fused core-modified planar antiaromatic 32π heptaphyrins: unusual synthesis and structural diversity.

The condensation reaction of fused dithienothiophene (DTT) diol with a core-modified tripyrrane led to the formation of acid and its concentration dependent products, sapphyrin and heptaphyrin. The single crystal X-ray analysis of sulphur and selenium heptaphyrin exhibits planar conformation owing to fusion. The experimental and theoretical calculations revealed the antiaromatic electronic structure of Hückel 4nπ.

meso-Aryl core-modified fused sapphyrins: syntheses and structural diversity.

Two new, fused core-modified expanded porphyrins, sapphyrins 3 and 4, were synthesized by a simple acid-catalyzed condensation of electron-rich and rigid precursor, dithienothiophene (DTT) diol, and core-modified tripyrrane. These sapphyrins exhibit structural diversity depending upon the heteroatom present in the macrocyclic framework, where the thiophene ring is inverted in 3, while the selenophene ring in 4 exists in normal and inverted form in the free base and addition of two protons shifts the equilibrium to inverted form.

Inflammation-inducible type 2 deiodinase expression in the leptomeninges, choroid plexus, and at brain blood vessels in male rodents.

Thyroid hormone regulates immune functions and has antiinflammatory effects. In promoter assays, the thyroid hormone-activating enzyme, type 2 deiodinase (D2), is highly inducible by the inflammatory transcription factor nuclear factor-κ B (NF-κB), but it is unknown whether D2 is induced in a similar fashion in vivo during inflammation. We first reexamined the effect of bacterial lipopolysaccharide (LPS) on D2 expression and NF-κB activation in the rat and mouse brain using in situ hybridization.

Molecular-level understanding of ground- and excited-state O-H...O hydrogen bonding involving the tyrosine side chain: a combined high-resolution laser spectroscopy and quantum chemistry study.

The present study combines both laser spectroscopy and ab initio calculations to investigate the intermolecular OH⋅⋅⋅O hydrogen bonding of complexes of the tyrosine side chain model chromophore compounds phenol (PH) and para-cresol (pCR) with H2 O, MeOH, PH and pCR in the ground (S0 ) state as well as in the electronic excited (S1 ) state. All the experimental and computational findings suggest that the H-bond strength increases in the S1 state and irrespective of the hydrogen bond acceptor used, the dispersion energy contribution to the total interaction energy is about 10-15 % higher in the S1 state compared to that in the S0 state. The alkyl-substituted (methyl; +I effect) H-bond acceptor forms a significantly stronger H bond both in the S0 and the S1 state compared to H2 O, whereas the aryl-substituted (phenyl; -R effect) H-bond donor shows a minute change in energy compared to H2 O.

Nanoformulations for delivery of biomolecules: focus on liposomal variants for siRNA delivery.

The potency of biomolecules assures therapy for as well as prevention of many disorders. However, their stability and delivery to the site of action remain a major challenge for successful therapeutic application. With advantages of nanoformulations, such as systemic environmental protection, controlled and site specific release, many of these bio-molecules have found their place in preventive, curative, or immunization-based therapies.

Calix[2]thia[4]phyrin: an expanded calixphyrin with aggregation-induced enhanced emission and anion receptor properties.

The synthesis of calix[2]thia[4]phyrin 3, a core-modified expanded calixphyrin, by an efficient synthetic route is reported. 3 exhibits an aggregation-induced enhanced emission (AIEE) phenomenon upon addition of increasing amounts of water. This is attributed to the restricted intramolecular rotation of the meso-aryl rings present on the sp(3) bridging carbons.

Polymeric modification and its implication in drug delivery: poly-ε-caprolactone (PCL) as a model polymer.

Biodegradable polymers provided the opportunity to explore beyond conventional drug delivery and turned out to be the focus of current drug delivery. In spite of availability of diverse class of polymers, several of these polymers lack important physicochemical and biological properties, limiting their widespread application in pharmaceutical drug delivery. However, most polymers in the form of blends, copolymers and functionally modified polymers have exhibited their applicability to overcome specific limitations and to produce novel and/or functionalized formulations for drug delivery as well as tissue engineering.

Poly-є-caprolactone based formulations for drug delivery and tissue engineering: A review.

Biodegradable polymer based novel drug delivery systems have provided many avenues to improve therapeutic efficacy and pharmacokinetic parameters of medicinal entities. Among synthetic biodegradable polymer, poly-є-caprolactone (PCL) is a polymer with very low glass transition temperature and melting point. Owing to its amicable nature and tailorable properties it has been trialed in almost all novel drug delivery systems and tissue engineering application in use/investigated so far.

Tetra-kis-(μ-3-meth-oxy-benzoato-κO:O)bis[acetonitrilecopper(II)].

The centrosymmetric binuclear Cu(II) title complex, [Cu(2)(C(8)H(7)O(3))(4)(CH(3)CN)(2)], has a paddle-wheel-type structure [Cu-Cu distance = 2.6433 (3) Å]. Each Cu(II) ion is coordin-ated by four O atoms from two 3-meth-oxy-benzoate ligands and one acetonitrile N atom in a square-pyramidal geometry.

Fluorescence enhancement effect for the determination of adenosine 5'-monophosphate with 9-anthracene carboxylic acid-cetyl trimethyl ammonium bromide system.

A fluorimetric method based on fluorescence enhancement effect was developed for the determination of adenosine 5'-monophosphate (AMP) with 9-anthracene carboxylic acid (9-ANCA)-cetyl trimethyl ammonium bromide (CTAB) system. Fluorescence intensity of 9-ANCA was decreased by the addition of CTAB but addition of AMP again rose the intensity of 9-ANCA gradually. The observed fluorescence enhancement is attributed to the competitive binding reaction of 9-ANCA and adenosine to CTAB.

Enhanced stability of G-quadruplexes from conformationally constrained aep-PNA backbone.

Nucleic (DNA) acids having contiguous stretch of G sequence form quadruplex structure, which is very critical to control cell division. Recently the existence of G-quadruplex in RNA is also reported in presence of monovalent metal ion. PNA is a promising DNA analogue which binds strongly to DNA to form PNA:DNA duplex or PNA(2):DNA triplex.

Spectrofluorimetric determination of 5-fluorouracil by fluorescence quenching of 9-anthracenecarboxylic acid.

Photo-induced intermolecular electron transfer (PET) interaction between excited singlet (S(1)) state of 9-anthracene carboxylic acid (9-ANCA) and DNA bases of pyrimidines as uracil and 5-fluorouracil (5-FU) has been studied in water and ethanol solutions using steady-state fluorescence spectroscopy. The intensity of all emission bands of 9-ANCA was quenched in presence of uracil and 5-FU by electron transfer reaction without formation of an exciplex. It was found that uracil and 5-fluorouracil acts as effective electron donors and simultaneously quench the fluorescence of electron-accepting sensitizer 9-ANCA.

Probiotic-Induced Priming of Innate Immunity to Protect Against Rotaviral Infection.

Understanding of probiotic-induced regulatory gene expression and networking is critical to further explore their roles in controlling infection. Transcriptional profile of selected innate immune genes in primary bovine intestinal epithelial cells was assessed over a time course of incubation with the probiotic Lactobacillus plantarum 299v. Based on gene expression results, a time point was chosen to prime epithelial cells with the probiotic prior to infection with rotavirus.

Wannier orbital overlap population (WOOP), Wannier orbital position population (WOPP) and the origin of anomalous dynamical charges.

Most d(0) transition metal (TM) oxides exhibit anomalously large Born dynamical charges associated with off-centering or motion of atoms along the TM-O chains. To understand their chemical origin, we introduce "Wannier orbital overlap population" (WOOP) and "Wannier orbital position population" (WOPP) in terms of the Wannier function based description of electronic structure obtained within first-principles density functional theory. We apply these concepts in a precise analysis of anomalous dynamical charges in PbTiO(3), BaTiO(3) and BaZrO(3) in the cubic perovskite structure.