Search results for "Cyclohexylamine"
showing 9 items of 9 documents
Tuning the selectivity of molecularly imprinted polymer extraction of arylcyclohexylamines: From class-selective to specific
2020
Abstract A molecularly imprinted polymer (MIP) has been prepared in presence of 3-hydroxy phencyclidine (3-OH PCP) as template by bulk polymerization using N,N-dimethylformamide, as porogenic solvent, for the selective solid-phase extraction (SPE) of arylcyclohexylamines from oral fluids. Experimental variables of the extraction procedure have been studied in order to increase both, extraction recovery of 3-OH PCP, used as model analyte, and imprinting factor. By modifying the composition of the washing solvent, the selectivity of the MIP extraction procedure can be tuned, moving from an arylcyclohexylamine selective method to a 3-OH PCP specific method. The applicability of the synthesized…
VCD studies on cyclic peptides assembled from L-α-amino acids and a trans-2-aminocyclopentane- or trans-2-aminocyclohexane carboxylic acid.
2010
The increasing interest in peptidomimetics of biological relevance prompted us to synthesize a series of cyclic peptides comprising trans-2-aminocyclohexane carboxylic acid (Achc) or trans-2-aminocyclopentane carboxylic acid (Acpc). NMR experiments in combination with MD calculations were performed to investigate the three-dimensional structure of the cyclic peptides. These data were compared to the conformational information obtained by electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) spectroscopy. Experimental VCD spectra were compared to theoretical VCD spectra computed quantum chemically at B3LYP/6-31G(d) density functional theory (DFT) level. The good agreem…
Artemisinin derivatives induce iron-dependent cell death (ferroptosis) in tumor cells
2015
Abstract Background Apoptosis and other forms of cell death have been intensively investigated in the past years to explain the mode of action of synthetic anticancer drugs and natural products. Recently, a new form of cell death emerged, which was termed ferroptosis, because it depends on intracellular iron. Here, the role of genes involved in iron metabolism and homeostasis for the cytotoxicity of ten artemisinin derivatives have been systematically investigated. Material and methods Log10IC50 values of 10 artemisinin derivatives (artesunate, artemether, arteether, artenimol, artemisitene, arteanuin B, another monomeric artemisinin derivative and three artemisinin dimer molecules) were co…
Bishistidyl heme hexacoordination, a key structural property in Drosophila melanogaster hemoglobin
2005
Hemoglobins at high concentration have been isolated long ago from some insect larvae living in hypoxic environments. Conversely, a monomeric hemoglobin has been discovered recently in the fruit fly Drosophila melanogaster as intracellular protein expressed both in larvae and in the adult fly. Such a finding indicates that the oxygen supply in insects may be more complex than previously thought, relying not only on O2 diffusion through the tubular tracheal system, but also on carrier-mediated transport and storage. We present here the crystal structure of recombinant D. melanogaster hemoglobin at 1.20 A resolution. Spectroscopic data show that the protein displays a hexacoordinated heme, wh…
CCDC 220523: Experimental Crystal Structure Determination
2004
Related Article: S.Matsui, Y.Yoshida, Y.Takagi, T.P.Spaniol, J.Okuda|2004|J.Organomet.Chem.|689|1155|doi:10.1016/j.jorganchem.2003.11.041
Solvent-Enhanced Diastereo- and Regioselectivity in the PdII-Catalyzed Synthesis of Six- and Eight-Membered Heterocycles viacis-Aminopalladation
2009
The Pd(II)-catalyzed intramolecular oxidative cyclization of tosyl-protected cis- and trans-N-allyl-2-aminocyclohexanecarboxamides was examined, and efficient syntheses of cyclohexane-fused pyrimidin-4-ones and 1,5-diazocin-6-ones were developed. In the course of the research, a marked solvent effect was observed on both the regio- and diastereoselectivity. Additionally, a novel Pd(II)-mediated domino oxidation, oxidative amination reaction was discovered. Our experimental and theoretical findings suggest that the reactions proceed via a cis-aminopalladation mechanism.
Identification and structural characterization of O-beta-ribosyl-(1"----2')-adenosine-5"-phosphate in yeast methionine initiator tRNA.
1990
We report in this paper on the complete structure determination of the modified nucleotide A*, now called Ar(p), that was previously identified in yeast methionine initiator tRNA as an isomeric form of O-ribosyl-adenosine bearing an additional phosphoryl-monoester group on its ribose2 moiety. By using the chemical procedure of periodate oxidation and subsequent beta-elimination with cyclohexylamine on mono- and dinucleotides containing Ar(p), we characterized the location of the phosphate group on the C-5" of the ribose2 moiety, and the linkage between the two riboses as a (1"----2')-glycosidic bond. Since the structural difference between phosphatase treated Ar(p) and authentic O-alpha-rib…
Antimykotische wirkstoffe. XXI. Aliphatisch und alicyclisch substituierte chlor-diallylamino-1l,3,5-triazine
1988
Aus der nucleophilen Substitution eines Chloratoms in 2,4-Dichlor-6-(diallylamino)-1,3,5-triazin (1) durch Amine (2a-g) gehen die Alkylamino- und Cycloalkylamino-chlor-(diallylamino)-1,3,5-triazine (3a-g) hervor. Von den zur Untermauerung des Strukturtyps 3 herangezogenen spektroskopischen Daten sind besonders charakteristisch die durch das 1,3,5-Triazinringsystem hervorgerufene IR-Bande bei 800 cm−1, die den Allylgruppen zuzuordnenden vier 1H-NMR-Signale zwischen 4,1–6,1 ppm und das beim massenspektroskopischen Abbau auftretende Rumpfkation m/e 158. Auffallend ausgepragt sind in Verbindungsklasse 3 antimykotische, trichomonazide und herbizide Wirksamkeit. By nucleophilic substitution of on…
Synthesis and Conformational Analysis of Saturated3,1,2-Benzoxazaphosphinine 2-Oxides
2005
N-Unsubstituted, N-methyl and N-benzyl cis- and trans-2(hydroxymethyl)cyclohexylamines were subjected to ring closure with phenylphosphonic dichloride, phenyl dichlorophosphate and bis(2-chloroethyl)phosphoramidic dichloride in order to synthesize P-epimeric diastereomers of the corresponding unsubsituted and N-substituted 2-phenyl-, 2phenoxy- and 2-[bis(2-chloroethyl)amino]octahydro-2H3,1,2-benzoxazaphosphinine 2-oxides. The stereochemistry and conformations of the prepared compounds were analyzed mainly by variable-temperature 1 H, 13 C and 31 P NMR spectroscopy. Geometry optimizations were performed for some trans-fused molecules by utilizing the B3LYP DFT method and a locally dense basi…