Search results for "amide"
showing 10 items of 3119 documents
CCDC 1532008: Experimental Crystal Structure Determination
2017
Related Article: P. J. Llabres-Campaner, J. Pitarch-Jarque, R. Ballesteros-Garrido, B. Abarca, R. Ballesteros, E. García-España|2017|Dalton Trans.|46|7397|doi:10.1039/C7DT00855D
Profiling of lipid species by normal-phase liquid chromatography, nanoelectrospray ionization, and ion trap–orbitrap mass spectrometry
2013
Detailed analysis of lipid species can be challenging due to their structural diversity and wide concentration range in cells, tissues, and biofluids. To address these analytical challenges, we devised a reproducible, sensitive, and integrated lipidomics workflow based on normal-phase liquid chromatography-Fourier transform mass spectrometry (LC-FTMS) and LC-ITMS(2) (ion trap tandem mass spectrometry) for profiling and structural analysis of lipid species. The workflow uses a normal-phase LC system for efficient separation of apolar and polar lipid species combined with sensitive and specific analysis powered by a chip-based nanoelectrospray ion source and a hybrid ion trap-orbitrap mass sp…
Identification of Three-Way DNA Junction Ligands through Screening of Chemical Libraries and Validation by Complementary in Vitro Assays
2019
International audience; The human genome is replete with repetitive DNA sequences that can fold into thermodynamically stable secondary structures such as hairpins and quadruplexes. Cellular enzymes exist to cope with these structures whose stable accumulation would result in DNA damage through interference with DNA transactions such as transcription and replication. Therefore, the chemical stabilization of secondary DNA structures offers an attractive way to foster DNA transaction-associated damages to trigger cell death in proliferating cancer cells. While much emphasis has been recently given to DNA quadruplexes, we focused here on three-way DNA junctions (TWJ) and report on a strategy t…
Determination of acrylamide in foods by pressurized fluid extraction and liquid chromatography-tandem mass spectrometry used for a survey of Spanish …
2006
An automated and rapid method for the determination of acrylamide in different food products is presented. The method involves pressurized fluid extraction (PFE) of foods with acetonitrile and precipitation with Carrez reagents. The final extract is analysed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (ESI-MS-MS). The main parameters affecting the performance of ESI-MS-MS and PFE were optimized using a design of experiments approach. The limit of quantification of the method was 5 microg kg(-1), and recoveries from incurred samples ranged between 93 and 101%. The accuracy was evaluated using the reference test materials FAPAS T3002, T3005 and T3011. …
4,5,6,7-Tetrahydro-isoxazolo-[4,5-c]-pyridines as a new class of cytotoxic Hsp90 inhibitors.
2014
Hsp90 is considered an interesting therapeutic target for anticancer drug development. Here we describe a new class of 4,5,6,7-tetrahydro-isoxazolo-[4,5-c]-pyridine compounds. A small library of derivatives has been synthesized and investigated. Some reported compounds show interesting properties combining both notable binding to Hsp90 and potent cell growth inhibitory activity. N-5 substitution with a 2,4 resorcinol carboxamide appears crucial for activity. Moreover, a derivative bearing a hydroxamic acid residue bound to C-3 amide portion was found to inhibit both Hsp90 and HDAC6.
Metal complexes of the carbonic anhydrase inhibitor methazolamide (Hmacm). Crystal structure of the Zn(macm)2 (NH3)2. Anticonvulsant properties of th…
1995
Complexes of Co(II), Cu(II), and Zn(II) with deprotonated methazolamide and ammonia are synthesized and characterized. The complex Zn(macm)2(NH3)2 crystallizes in the monoclinic C2/c space group with a = 13.468(1), b = 6.759(1), c = 23.014(2) A, beta = 90.27(1), and Z = 4. The structure was refined to R = 0.049 (Rw = 0.053). The Zn(II) ion is coordinated to two deprotonated sulfonamido nitrogen atoms of the macm- ligand and two nitrogen atoms of the ammonia ligands in a distorted tetrahedron. The Zn(macm)2(NH3)2 complex is shown to be a simple model for the methazolamide inhibition of CA. EHMO calculations applied to fractional coordinates of the Zn(macm)2(NH3)2 complex indicate that the at…
Axial growth of hexactinellid spicules: Formation of cone-like structural units in the giant basal spicules of the hexactinellid Monorhaphis
2008
The glass sponge Monorhaphis chuni (Porifera: Hexactinellida) forms the largest bio-silica structures on Earth; their giant basal spicules reach sizes of up to 3 m and diameters of 8.5 mm. Previously, it had been shown that the thickness growth proceeds by appositional layering of individual lamellae; however, the mechanism for the longitudinal growth remained unstudied. Now we show, that the surface of the spicules have towards the tip serrated relief structures that are consistent in size and form with the protrusions on the surface of the spicules. These protrusions fit into the collagen net that surrounds the spicules. The widths of the individual lamellae do not show a pronounced size …
Density Functional Study of Spin State in CpM(NO)X2 (M = Mo, Cr; X = Cl, NH2, CH3): Spectrochemical and Nephelauxetic Effects in Organometallic Comp…
1998
International audience; The relationship between spin state and metal−ligand bonding interactions in CpM(NO)X2 species was investigated using density functional computational techniques. The geometries of CpM(NO)Cl2 (M = Cr, Mo), CpCr(NO)(NH2)X, and CpCr(NO)(CH3)X (X = Cl, CH3) were optimized at the DFT-B3LYP level for both the diamagnetic (S = 0) and paramagnetic (S = 1) electronic configurations. While the geometric parameters of the singlet compounds matched well with structures determined experimentally, the Cr−NO bond lengths in the triplet species exceeded the experimentally observed range by a significant margin, thereby indicating a propensity for nitrosyl-ligand dissociation from t…
Common and form-specific cell wall antigens of Candida albicans as released by chemical and enzymatic treatments.
1996
In order to investigate the antigenic properties of the proteins and mannoproteins present in the cell surface of Candida albicans, and to identify individual antigenic moieties and their distribution, a number of polyclonal antisera were obtained by immunizing rabbits with chemical and enzymatic cell wall extracts obtained from intact cells from both growth forms (yeast and mycelium) of the fungus. Prior to injection, wall moieties present in the extracts were subjected to different treatments and/or purification procedures such as adsorption onto polystyrenelatex microbeads or electrophoretic separation. When used as probes in indirect immunofluorescence assays, the different antisera gav…
Altered pore-forming properties of proteolytically nicked staphylococcal alpha-toxin
1993
Staphylococcal alpha-toxin is a single-chain polypeptide with a molecular weight of 34,000 that hexamerizes in lipid bilayers to form pores of 1-1.5 nm effective diameter in membranes. We demonstrate that limited proteolysis of purified alpha-toxin with proteinase K generates a hemolytically active product that yields one major protein band of 17-18 kDa in SDS-polyacrylamide gel electrophoresis. The 17-18-kDa protein band harbors two major fragments of similar size representing the N- and C-terminal halves, which remain associated with each other in non-denaturing buffers but dissociate in 6 M urea. Dissociation in urea leads to loss of hemolytic activity. In contrast, unnicked alpha-toxin …