Cascade Synthesis in Water: Michael Addition/Hemiketalization/Retro-Claisen Fragmentation Catalyzed by CatAnionic Vesicular Nanoreactor from Dithiocarbamate.

N,N-didodecylammonium N,N-didodecyldithiocarbamate (AmDTC-CC) underwent self-assembly to form a CatAnionic vesicular nanoreactor in water. AmDTC-CC can be readily prepared by condensation between N,N-didodecylamine and carbon disulfide. Previously, the cascade Michael addition/hemiketalization/retro-Claisen fragmentation was reported, but it required petroleum-based organic solvents as reaction media.

Complement receptor 3-dependent engagement by β-glucan modulates dendritic cells to induce regulatory T-cell expansion.

is an important pathogen causing invasive infection associated with a high mortality rate. One mechanism that causes the failure of eradication is an increase in regulatory T cells (Treg), which play a major role in immune suppression and promoting pathogenicity. To date, how induces a Treg response remains unclear.

Glycosylation of -pentenyl glycosides using bromodiethylsulfonium salt as an activator: interception of the glycosyl intermediate by chloride ion transfer.

Utilization of -pentenyl glycosides (NPGs) in modern carbohydrate synthesis may be hindered by their sluggish activation, which results from reversible halogenation and cyclization processes. Bromodiethylsulfonium bromopentachloroantimonate (BDSB) has been previously shown to be a powerful brominating agent for the cation-π polyene cyclization of less reactive and electron-poor polyenes. This study demonstrates the activation of NPGs using BDSB as a powerful brominating agent.

Surfactant-Assisted Ozonolysis of Alkenes in Water: Mitigation of Frothing Using Coolade as a Low-Foaming Surfactant.

Aqueous-phase ozonolysis in the atmosphere is an important process during cloud and fog formation. Water in the atmosphere acts as both a reaction medium and a reductant during the ozonolysis. Inspired by the atmospheric aqueous-phase ozonolysis, we herein report the ozonolysis of alkenes in water assisted by surfactants.

Membrane-permeable trehalose improves the freezing ability and developmental competence of in-vitro matured feline oocytes.

Oocytes are highly sensitive to cryopreservation, which frequently results in an irreversible loss of developmental competence. We examined the effect of membrane-permeable trehalose on the freezing ability of feline oocytes matured in vitro. In Experiment 1, intracellular trehalose (trehalose hexaacetate; Tre-(OAc)) was synthesized from trehalose precursor and subjected to spectroscopic characterization.

Interaction Between Dendritic Cells and β-Glucan Partially Depends on Dectin-1 and It Promotes High IL-10 Production by T Cells.

Host- interaction has been broadly studied during infection, with a progressive shift in focus toward non- species. is an emerging multidrug resistant pathogen causing rising morbidity and mortality worldwide. Therefore, understanding the interplay between the host immune system and is critically important.

Surfactant-mediated thioglycosylation of 1-hydroxy sugars in water.

Thioglycosides are an important class of sugars, since they can be used as non-ionic biosurfactants, biomimetic glycosides, and building blocks for carbohydrate synthesis. Previously, Brønsted- or Lewis-acid-catalyzed dehydrative glycosylations between a 1-hydroxy sugar and a thiol have been reported to yield open-chain dithioacetal sugars as the major products instead of the desired thioglycosides. These dithioacetal sugars are by-products derived from the endocyclic bond cleavage of the thioglycosides.

Fusigen Reduces Intracellular Reactive Oxygen Species and Nitric Oxide Levels.

Background/aim: Oxidative stress caused by the production of excessive cellular reactive oxygen species (ROS) and high levels of nitric oxide contribute to several human pathologies. This study aimed to examine the anti-oxidant effects of fusigen, a compound produced from Aureobasidium melanogenum.

Materials And Methods: Extracts of A.

Enzymatic hydrolysis of tropical weed xylans using xylanase from PBUAP46 for xylooligosaccharide production.

The maximum yield of xylanase from PBUAP46 was 5.19 ± 0.08 U ml when cultured in a production medium containing 3.

Cell wall mannan of Candida krusei mediates dendritic cell apoptosis and orchestrates Th17 polarization via TLR-2/MyD88-dependent pathway.

Dendritic cells (DCs) abundantly express diverse receptors to recognize mannans in the outer surface of Candida cell wall, and these interactions dictate the host immune responses that determine disease outcomes. C. krusei prevalence in candidiasis worldwide has increased since this pathogen has developed multidrug resistance.

An α-1,6-and α-1,3-linked glucan produced by Leuconostoc citreum ABK-1 alternansucrase with nanoparticle and film-forming properties.

Alternansucrase catalyses the sequential transfer of glucose residues from sucrose onto another sucrose molecule to form a long chain polymer, known as "alternan". The alternansucrase-encoding gene from Leuconostoc citreum ABK-1 (Lcalt) was successfully cloned and expressed in Escherichia coli. Lcalt encoded LcALT of 2,057 amino acid residues; the enzyme possessed an optimum temperature and pH of 40 °C and 5.

Synthesis and DNA/RNA Binding Properties of Conformationally Constrained Pyrrolidinyl PNA with a Tetrahydrofuran Backbone Deriving from Deoxyribose.

Sugar-derived cyclic β-amino acids are important building blocks for designing of foldamers and other biomimetic structures. We report herein the first synthesis of a C-activated N-Fmoc-protected trans-(2S,3S)-3-aminotetrahydrofuran-2-carboxylic acid as a building block for Fmoc solid phase peptide synthesis. Starting from 2-deoxy-d-ribose, the product is obtained in a 6.

Synthesis and reactivity of 4'-deoxypentenosyl disaccharides.

4-Deoxypentenosides (4-DPs) are versatile synthons for rare or higher-order pyranosides, and they provide an entry for structural diversification at the C5 position. Previous studies have shown that 4-DPs undergo stereocontrolled DMDO oxidation; subsequent epoxide ring-openings with various nucleophiles can proceed with both anti or syn selectivity. Here, we report the synthesis of α- and β-linked 4'-deoxypentenosyl (4'-DP) disaccharides, and we investigate their post-glycosylational C5' additions using the DMDO oxidation/ring-opening sequence.

Enhanced water-solubility and mucoadhesion of N,N,N-trimethyl-N-gluconate-N-homocysteine thiolactone chitosan.

A water-soluble chitosan with improved mucoadhesion was prepared by modifying 19.4% of the amine groups of chitosan to trimethylammonium and conjugation of gluconolactone (GLU) and homocysteine thiolactone (HT) onto the remaining amine groups of the chitosan backbone. The derived trimethyl-gluconate-HT-chitosan (TM-GN-HT-chitosan) was confirmed by Fourier Transform Infrared spectroscopy, NMR and thermogravimetric analysis.

Glycosyl dithiocarbamates: β-selective couplings without auxiliary groups.

In this article, we evaluate glycosyl dithiocarbamates (DTCs) with unprotected C2 hydroxyls as donors in β-linked oligosaccharide synthesis. We report a mild, one-pot conversion of glycals into β-glycosyl DTCs via DMDO oxidation with subsequent ring opening by DTC salts, which can be generated in situ from secondary amines and CS2. Glycosyl DTCs are readily activated with Cu(I) or Cu(II) triflate at low temperatures and are amenable to reiterative synthesis strategies, as demonstrated by the efficient construction of a tri-β-1,6-linked tetrasaccharide.

PRACTICAL SYNTHESIS OF AROMATIC DITHIOCARBAMATES.

Oxidation-sensitive N,N-diaryl dithiocarbamates (DTCs) are synthesized in good yields by the generation of metal amide salts from N-benzoyl precursors, followed by addition of CS. para-Substituted diphenylamines are prepared by electrophilic aromatic substitution of diphenylbenzamide and saponification. Deacylation of electron-rich species such as bis(p-dimethylaminophenyl)benzamide is challenging because of the oxidative sensitivity of the anionic intermediate but could be achieved in good yield by using n-BuLi to generate a hemiaminal adduct, prior to acidification.

Glycal assembly by the in situ generation of glycosyl dithiocarbamates.

Glycal assembly offers an expedient entry into β-linked oligosaccharides, but epoxyglycal donors can be capricious in their reactivities. Treatment with Et(2)NH and CS(2) enables their in situ conversion into glycosyl dithiocarbamates, which can be activated by copper triflate for coupling with complex or sterically congested acceptors. The coupling efficiency can be further enhanced by in situ benzoylation, as illustrated in an 11-step synthesis of a branched hexasaccharide from glucals in 28% isolated yield and just four chromatographic purifications.