Search results for "Azine"

ChemInform Abstract: Synthetic O-Glycopeptides as Model Substrates for Glycosyltransferases.

2010

Abstract A new approach to O-glycopeptides of the glucosamine type is described. N-Urethane protected, peracetylated glucosamine is converted into its 1-thio (1-bromo) derivative and used for glycosylation of a variety of protected serine or threonine derivatives as acceptors. The urethane group is easily exchanged for the natural N-acetyl moiety and O-deacetylation is achieved with hydrazine/methanol. The resulting O-GlcNAc derivatives are subjected to an enzymatic galactosylation procedure using β-1,4-galactosyltransferase (EC 2.4.1.22) to furnish O-glycopeptides of the neolactosamine type.

Photocatalytic Partial Oxidation of 5‐Hydroxymethylfurfural (HMF) to 2,5‐Diformylfuran (DFF) Over a Covalent Triazine Framework in Water

2020

Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography

2005

Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical …

Extrapyramidal Symptoms and their Relationship to Clinical Efficacy under Perphenazine Treatment*

1991

In order to verify the hypothesis of a strict relationship between clinical improvement and extrapyramidal side-effects, especially micrographia, twenty-two acutely ill schizophrenics were treated with perphenazine in a controlled prospective 28-day trial. During the study period, psychopathometric data, prolactin plasma levels, and handwriting samples were collected. According to the remission criteria fixed before the study began (both BPRS ≤ 25 and GAS ≥ 80 points), 45.5% (10/22) of the total patient sample were classified as treatment responders. Handwriting tests were quantified in 21 patients. "Positive" handwriting results, i. e., a reduction of at least 13% in the overall area of 50…

Modulation of N···I and +N−H···Cl−···I Halogen Bonding: Folding, Inclusion, and Self-Assembly of Tri- and Tetraamino Piperazine Cyclophanes

2010

The acidity of the crystallization conditions was successfully employed in modulating the balance between the robust intramolecular hydrogen bonding (HB) and intermolecular halogen bonding (XB) observed in large tri- (1) and tetraamino (2) piperazine cyclophanes. A careful crystallization of the title XB acceptor cyclophanes with a strong bidentate XB donor 1,4-diiodotetrafluorobenzene (F4DIB) from CHCl3:MeOH, dimethylformamide (DMF), or HCl:H2O:EtOH resulted in X-ray quality crystals of 1·F4DIB, 2@DMF, 2·2@F4DIB, [1H3]Cl3·(F4DIB)6, and [2H6]Cl6·(F4DIB)2. The intramolecular hydrogen bonding pattern in 1 and 2 was retained in neutral protic and aprotic solvents, and regular N−H···N hydrogen …

Fluorine Scan of Inhibitors of the Cysteine Protease Human Cathepsin L: Dipolar and Quadrupolar Effects in the π-Stacking of Fluorinated Phenyl Rings…

2016

The π-stacking of fluorinated benzene rings on protein backbone amide groups was investigated, using a dual approach comprising enzyme-ligand binding studies complemented by high-level quantum chemical calculations. In the experimental study, the phenyl substituent of triazine nitrile inhibitors of human cathepsin L (hCatL), which stacks onto the peptide amide bond Gly67-Gly68 at the entrance of the S3 pocket, was systematically fluorinated, and differences in inhibitory potency were measured in a fluorimetric assay. Binding affinity is influenced by lipophilicity (clog P), the dipole and quadrupole moments of the fluorinated rings, but also by additional interactions of the introduced fluo…

Effects of Terbuthylazine on Soil Fauna and Decomposition Processes

1996

Abstract Acute lethal and sublethal effects of terbuthylazine and the commercial herbicide preparation Gardoprim [terbuthylazine is the active ingredient (a.i.)] on soil organisms (microbes, oppioid mites, two gamasid mite species, enchytraeids, and nematodes) were studied. In the humus soil terbuthylazine had no toxic effects on soil animals tested. However, the herbicide preparation had acute toxic effects on enchytraeids [no-observed-effect level (NOEL) 1.0 g a.i./m 2 ] and both gamasid mites (NOEL 2.4 and 5.0 g a.i./m 2 ). According to filter paper test, the LC 50 value for oppioid mites was 14.5 g a.i./m 2 . In the humus soil the commercial preparation caused no dose-related mortality …

Detection of oxidative mutagenesis by isoniazid and other hydrazine derivatives in Escherichia coli WP2 tester strain IC203, deficient in OxyR: stron…

1998

Abstract Strain IC203, deficient in the OxyR function, was sensitive to both cytotoxic and mutagenic effects of isoniazid (INH) whereas its parent, WP2 uvrA /pKM101, was resistant to these effects. Four other hydrazine compounds, hydrazine hydrate (HZH), phenylhydrazine (PHZ), hydralazine (HLZ) and nialamide (NLD), were mutagenic in WP2 uvrA /pKM101. Increases in mutagenicity were observed in IC203 for HZH and PHZ but not for HLZ and NLD. Growth inhibition zones by HZH, PHZ and NLD were larger in IC203 than in WP2 uvrA /pKM101. The enhancements in the effects of INH, HZH and PHZ in IC203 with respect to its oxyR + parent are considered to be caused by the production of reactive oxygen speci…

Selective photocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxaldehyde by polymeric carbon nitride-hydrogen peroxide adduct

2018

Abstract Polymeric carbon nitride-hydrogen peroxide adduct (PCN-H2O2) has been prepared, thoroughly characterised and its application for selective photocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxaldehyde (FDC) in aqueous suspension has been studied. The PCN-H2O2 adduct is stable in aqueous suspension under UV and solar irradiation up to 100 °C. It is also stable up to 200 °C if heated in air, while at temperatures close to 300 °C its decomposition takes place. Based on the obtained characterisation data it has been proposed that H2O2 attaches to the non-polymerised carbon nitride species and to the heptazine nitrogen atoms, thus producing strong hydrogen bond…

Metal-Organic Nanocapsules with Functionalized s-Heptazine Ligands.

2020

A metalloorganic capsule was synthesized where the ligand is a derivative of heptazine with three carboxylic groups that are coordinated to CuII cations, forming paddle-wheel motifs. Each nanocapsule is neutral, with 12 CuII centers and 8 ligands adopting a rhombicuboctahedron shape. It has almost 3 nm diameter, and the main intermolecular interactions in the solid are π··· π stacking between the C6N7 heptazine moieties. The nanocapsules can form monolayers deposited on graphite as observed by atomic force microscopy, which confirms their stability in solution. peerReviewed