Matthieu Etter

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A method is presented based on graph theory for categorizing hydrogen-bond motifs in such a way that complex hydrogen-bond patterns can be disentangled, or decoded, systematically and consistently. This method is based on viewing hydrogen-bond patterns topologically as if they were intertwined nets with molecules as the nodes and hydrogen bonds as the(More)
Both molecules occur in slightly folded conformations, characterized by phi 2 = -93.7 degrees in L-His-Gly and an unusual phi 2 = 60.2 degrees in L-Asp-L-Phe. The peptide linkage of L-His-Gly displays a substantial deviation from planarity with omega 1 = -163.5 degrees. The crystal packing is arranged in thick hydrophilic layers separated by hydrophobic(More)
If classic phosphodiesterase-5 (PDE-5) inhibitors are well known, new synthetic PDE-5 analogues are of more recent introduction. Some of them have already been tested in dietary supplements. We describe here a rape case following the consumption of pills bought on the Internet and containing new synthetic PDE-5 inhibitors. The assailant declared that he(More)
The anti-anti isomer of naltrexonazine (1) was synthesized, and its configuration was confirmed by X-ray crystallography. The syn-anti isomer is readily converted to 1 under acidic conditions. The apparent equal receptor binding of 1 and syn-anti isomer indicates that isomerization of the azine moiety may take place under the conditions of biological(More)
N-Acetylbenzamide, C9H9NO2 (I) Mr = 163.18, orthorhombic, Pbca, a = 8.990 (2), b = 9.208 (3), c = 19.619 (3) A, V = 1624 (1) A3, Z = 8, Dx = 1.335 (1) g cm-3, lambda(Mo K alpha) = 0.710569 A, mu = 0.89 cm-1, F(000) = 688, T = 295 K, R = 0.031 for 865 observed reflections. N-Propionylbenzamide, C10H11NO2 (II), Mr = 177.20, monoclinic, P2(1)/c, a = 10.485(More)
Three separate cases of child administration of prescription drugs are described. Following liquid-liquid extraction, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to identify and quantify methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenyl-1-pyrrolidine (EDDP), tramadol, amitriptyline, and nortriptyline in children's(More)
Crystal structures of all available unblocked linear peptides with two to five residues were retrieved from the Cambridge Structural Database and their intermolecular contacts and packing modes studied using molecular graphics. This survey reveals that interactions between hydrophobic portions of the molecules are critically important in determining the(More)
C9H11NO2.C9H12NO2+.CHO2-, M(r) = 376.41, monoclinic, P2(1), a = 11.507 (6), b = 5.638 (3), c = 14.610 (5) A, beta = 100.65 (4) degrees, V = 932 (1) A3, Z = 2, Dx = 1.342 g cm-3, lambda(Mo K alpha) = 0.7107 A, mu = 0.94 cm-1, F(000) = 400, T = 295 K, final R = 0.047 for 2693 observed reflections. The phenylalanine zwitterion and the phenylalanine cation form(More)
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