Search results for "Ceta"

Catechol Acetonide Glycidyl Ether (CAGE): A Functional Epoxide Monomer for Linear and Hyperbranched Multi-Catechol Functional Polyether Architectures

2016

A protected catechol-containing epoxide monomer, catechol acetonide glycidyl ether (CAGE), is introduced. CAGE is conveniently obtained in three steps and enables the incorporation of surface-active catechol moieties into a broad variety of hydrophilic and biocompatible polyether architectures by copolymerization. Via acidic cleavage of the acetal protecting groups, the polymer-attached catechol functionalities are liberated and available for surface attachment or metal complexation. CAGE has been copolymerized with ethylene oxide and glycidol to obtain both linear poly(ethylene glycol) and hyperbranched polyglycerol copolymers, respectively, with multiple surface-adhesive catechol moieties…

The “Needle in the Haystack” Makes the Difference: Linear and Hyperbranched Polyglycerols with a Single Catechol Moiety for Metal Oxide Nanoparticle …

2014

Multifunctional linear (CA-linPG) and hyperbranched polyglycerols (CA-hbPG) bearing a single catechol unit were synthesized by use of an acetonide-protected catechol initiator for the anionic polymerization of ethoxyethyl glycidyl ether (EEGE) and glycidol, respectively. A key feature for the synthesis of the hyperbranched structures was a selective, partial acetal deprotection step. The single catechol unit among a large number of aliphatic 1,2- and 1,3-diol moieties (i.e., the “needle in the haystack”) in both linear and hyperbranched polyglycerols permits dispersion of transition metal oxide nanoparticles in brine, as demonstrated for manganese oxide (MnO) nanoparticles. Molecular weight…

Superoxide generation by human neutrophils induced by low doses of Escherichia coli hemolysin.

1991

Escherichia coli hemolysin (Hly) was isolated from bacterial culture supernatants by polyethylene glycol precipitation and centrifugation in glycerol density gradients. The toxin preparations contained less than 1 mol of lipopolysaccharide per 10 mol of protein, and they had no fatty acids. The capacity of purified hemolysin to stimulate superoxide anion production in polymorphonuclear leukocytes was monitored kinetically in a lumimeter by using the lucigenin assay and was correlated with the kinetics of transmembrane pore formation. When applied to leukocytes suspended in protein-free buffer, very low concentrations (0.02 to 0.1 HU/ml) of the toxin strongly stimulated the production of sup…

Rôle of the nucleus in the maintenance of the protein level in the algaAcetabularia mediterranea

1954

Sono state studiate le variazioni del rapporto tra l'N proteico e non proteico in segmenti rigeneranti, nucleati ed anucleati, diAcetabul. medit. I risultati ottenuti hanno dimostrato che il predetto rapporto aumenta in entrambi i segmenti il primo giorno dopo l'operazione. Nei giorni seguenti esso diminuisce in entrambi i segmenti, ma piu sensibilmente in quelli anucleati, nei quali va al di sotto del valore medio delle alghe normali gia dopo il 3°–4° giorno.

Multiple signal transduction pathways regulate clusterin (gp 80) gene expression in MDCK cells

1996

ABSTRACT Clusterin (gp 80, apolipoprotein J, TRPM-2) is a widely expressed multifunctional glycoprotein. Its demonstrated and proposed functions include the transport of lipids and membrane fragments, the inhibition of the cytolytic action of the terminal complement complex and the modulation of cell—cell interactions. The expression of the gene is enhanced during tissue injury and remodelling and by hormone-withdrawal-induced apoptosis of prostate and mammary cells. We show here that, in the kidney-derived epithelial cell line MDCK, clusterin mRNA is repressed by glucocorticoids and by progesterone. Treatment with epidermal growth factor also represses clusterin gene expression in MDCK cel…

Infantile Central Sleep Apnea - Improvement With Acetazolamide

1999

Retention of aroma compounds in starch matrices: competitions between aroma compounds toward amylose and amylopectin

2002

International audience; The retention of three aroma compounds-isoamyl acetate, ethyl hexanoate, and linalool--from starch-containing model food matrices was measured by headspace analysis, under equilibrium conditions. We studied systems containing standard or waxy corn starch with one or two aroma compounds. The three studied aroma compounds interact differently: ethyl hexanoate and linalool form complexes with amylose, and isoamyl acetate cannot. However, in systems containing one aroma compound, we observed with both starches a significant retention of the three molecules. These results indicate that amylopectin could play a role in the retention of aroma. In systems containing two arom…

Cytotoxicity and antileishmanial activity of Annona muricata pericarp

2000

Abstract Hexane, ethyl acetate and methanol extracts of Annona muricata pericarp were tested in vitro against Leishmania braziliensis and L. panamensis promastigotes, and against cell line U-937. The ethyl acetate extract was more active than the other extracts and even of Glucantime® used as reference substance. Its fractionation led to the isolation of three acetogenins — annonacin, annonacin A and annomuricin A.

In vitro prediction of in vivo absorption of ibuprofen from suspensions through rational choice of dissolution conditions

2020

Two ibuprofen suspension formulations were investigated for their dissolution in various bicarbonate, phosphate and acetate buffers. Phosphate and acetate gave faster release than bicarbonate at comparable molarities. Nevertheless, mass transport modelling using the reversible non-equilibrium (RNE) approach enabled the calculation of phosphate molarities that gave good matches to physiological bicarbonate in terms of ibuprofen dissolution. This shows that developing surrogate buffers for bicarbonate that are devoid of the technical difficulties associated with the bicarbonate-CO2 systems is possible. In addition, the intestinal dissolution kinetics of the tested suspensions were determined …

‘One-Pot’ Synthesis of Raumacline from Ajmaline

1993

For the alkaloid raumacline (2), which is a biotransformation product of ajmaline (1) in Rauwolfia serpentina cell cultures, an efficient ‘one-pot’ synthesis was developed using a NaBH4/riboflavin/light-mediated transformation of 1 into 2 with a total yield of 86%.