Fluorescent Molecularly Imprinted Polymer Layers against Sialic Acid on Silica-Coated Polystyrene Cores-Assessment of the Binding Behavior to Cancer Cells.

Sialic acid (SA) is a monosaccharide usually linked to the terminus of glycan chains on the cell surface. It plays a crucial role in many biological processes, and hypersialylation is a common feature in cancer. Lectins are widely used to analyze the cell surface expression of SA.

Exploring divalent conjugates of 5--acetyl-neuraminic acid as inhibitors of coxsackievirus A24 variant (CVA24v) transduction.

Coxsackievirus A24 variant (CVA24v) is responsible for several outbreaks and two pandemics of the highly contagious eye infection acute hemorrhagic conjunctivitis (AHC). Currently, neither prevention (vaccines) nor treatments (antivirals) are available for combating this disease. CVA24v attaches to cells by binding Neu5Ac-containing glycans on the surface of cells which facilitates entry.

Exploring the Effect of Structure-Based Scaffold Hopping on the Inhibition of Coxsackievirus A24v Transduction by Pentavalent N-Acetylneuraminic Acid Conjugates.

Coxsackievirus A24 variant (CVA24v) is the primary causative agent of the highly contagious eye infection designated acute hemorrhagic conjunctivitis (AHC). It is solely responsible for two pandemics and several recurring outbreaks of the disease over the last decades, thus affecting millions of individuals throughout the world. To date, no antiviral agents or vaccines are available for combating this disease, and treatment is mainly supportive.

Synthesis of 4--Alkylated -Acetylneuraminic Acid Derivatives.

The synthesis of 4--alkyl analogues of -acetylneuraminic acid (Neu5Ac) and the scope of the reaction are described. Activated alkyl halides and sulfonates and primary alkyl iodides give products in useful yields. The utility of the methodology is exemplified using a thiophenyl Neu5Ac building block to synthesize a 4--alkyl DANA analogue.

Pentavalent Sialic Acid Conjugates Block Coxsackievirus A24 Variant and Human Adenovirus Type 37-Viruses That Cause Highly Contagious Eye Infections.

Coxsackievirus A24 variant (CVA24v) and human adenovirus 37 (HAdV-37) are leading causative agents of the severe and highly contagious ocular infections acute hemorrhagic conjunctivitis and epidemic keratoconjunctivitis, respectively. Currently, neither vaccines nor antiviral agents are available for treating these diseases, which affect millions of individuals worldwide. CVA24v and HAdV-37 utilize sialic acid as attachment receptors facilitating entry into host cells.

Sialic Acid-Containing Glycans as Cellular Receptors for Ocular Human Adenoviruses: Implications for Tropism and Treatment.

Human adenoviruses (HAdV) are the most common cause of ocular infections. Species B human adenovirus type 3 (HAdV-B3) causes pharyngoconjunctival fever (PCF), whereas HAdV-D8, -D37, and -D64 cause epidemic keratoconjunctivitis (EKC). Recently, HAdV-D53, -D54, and -D56 emerged as new EKC-causing agents.

14-3-3 proteins activate Pseudomonas exotoxins-S and -T by chaperoning a hydrophobic surface.

Pseudomonas are a common cause of hospital-acquired infections that may be lethal. ADP-ribosyltransferase activities of Pseudomonas exotoxin-S and -T depend on 14-3-3 proteins inside the host cell. By binding in the 14-3-3 phosphopeptide binding groove, an amphipathic C-terminal helix of ExoS and ExoT has been thought to be crucial for their activation.

Screening for Inhibitors of Acetaldehyde Dehydrogenase (AdhE) from Enterohemorrhagic Escherichia coli (EHEC).

Acetaldehyde dehydrogenase (AdhE) is a bifunctional acetaldehyde-coenzyme A (CoA) dehydrogenase and alcohol dehydrogenase involved in anaerobic metabolism in gram-negative bacteria. This enzyme was recently found to be a key regulator of the type three secretion (T3S) system in Escherichia coli. AdhE inhibitors can be used as tools to study bacterial virulence and a starting point for discovery of novel antibacterial agents.

Structure-activity relationships for lipoprotein lipase agonists that lower plasma triglycerides in vivo.

The risk of cardiovascular events increases in individuals with elevated plasma triglyceride (TG) levels, therefore advocating the need for efficient TG-lowering drugs. In the blood circulation, TG levels are regulated by lipoprotein lipase (LPL), an unstable enzyme that is only active as a non-covalently associated homodimer. We recently reported on a N-phenylphthalimide derivative (1) that stabilizes LPL in vitro, and moderately lowers triglycerides in vivo (Biochem.

Triazole linker-based trivalent sialic acid inhibitors of adenovirus type 37 infection of human corneal epithelial cells.

Adenovirus type 37 (Ad37) is one of the principal agents responsible for epidemic keratoconjunctivitis (EKC), a severe ocular infection that remains without any available treatment. Recently, a trivalent sialic acid derivative (ME0322, Angew. Chem.

Towards small molecule inhibitors of mono-ADP-ribosyltransferases.

Protein ADP-ribosylation is a post-translational modification involved in DNA repair, protein degradation, transcription regulation, and epigenetic events. Intracellular ADP-ribosylation is catalyzed predominantly by ADP-ribosyltransferases with diphtheria toxin homology (ARTDs). The most prominent member of the ARTD family, poly(ADP-ribose) polymerase-1 (ARTD1/PARP1) has been a target for cancer drug development for decades.

Identification of a small molecule that stabilizes lipoprotein lipase in vitro and lowers triglycerides in vivo.

Patients at increased cardiovascular risk commonly display high levels of plasma triglycerides (TGs), elevated LDL cholesterol, small dense LDL particles and low levels of HDL-cholesterol. Many remain at high risk even after successful statin therapy, presumably because TG levels remain high. Lipoprotein lipase (LPL) maintains TG homeostasis in blood by hydrolysis of TG-rich lipoproteins.

Symmetric dithiodigalactoside: strategic combination of binding studies and detection of selectivity between a plant toxin and human lectins.

Thioglycosides offer the advantage over O-glycosides to be resistant to hydrolysis. Based on initial evidence of this recognition ability for glycosyldisulfides by screening dynamic combinatorial libraries, we have now systematically studied dithiodigalactoside on a plant toxin (Viscum album agglutinin) and five human lectins (adhesion/growth-regulatory galectins with medical relevance e.g.

Phosphine-mediated disulfide metathesis in aqueous media.

Dynamic carbohydrate systems have been efficiently generated through phosphine-mediated disulfide metathesis in aqueous media. The protein compatibility and binding features of the dynamic systems were demonstrated in situ using (1)H STD NMR.

pH-dependent mutarotation of 1-thioaldoses in water. Unexpected behavior of (2s)-D-aldopyranoses.

The pH-dependent mutarotation of 1-thioaldopyranoses in aqueous media has been investigated. Anomerization readily occurred at lower and neutral pH for all aldopyranoses studied, whereas mainly for (2S)-D-aldopyranoses at higher pH. 1-Thio-D-mannopyranose and 1-thio-D-altropyranose showed very strong pH dependence where the anomeric equilibrium ratios changed dramatically from a preference for the β-anomer at lower pH to the α-anomer at higher pH.

Towards dynamic drug design: identification and optimization of beta-galactosidase inhibitors from a dynamic hemithioacetal system.

A discovery strategy relying on the identification of fragments through resolution of a constitutional dynamic system, coupled to subsequent static ligand design and optimization, is demonstrated. The strategic design and synthesis of the best molecular fragments identified from a dynamic hemithioacetal system into static ligand structures yielded a range of beta-galactosidase inhibitors. Two series of structures mimicking the hemithioacetal motif were envisaged: thioglycosides and C-glycosides.

Phosphine-catalyzed disulfide metathesis.

The reaction between disulfides and phosphines generates a reversible disulfide metathesis process.

Ion-conduction pathways in self-organised ureidoarene-heteropolysiloxane hybrid membranes.

This paper reports on hybrid organic-inorganic dense membrane materials in which protons and ions are envisioned to diffuse along the hydrophilic pathways. The hierarchical generation of functional hybrid materials was realised in two steps. First, the self-assembling properties of 3-(ureidoarene)propyltriethoxysilane compounds 1-5 in aprotic solvents were determined, revealing the formation of supramolecular oligomers.