- Examination of the Aspirin Acetylation Site of Human Serum Albumin by 13C NMR Spectroscopy
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Human serum albumin has been specifically acetylated using aspirin in which the methyl carbon of the acetyl group was enriched to 90percent 13C.A single resonance at 23.13 ppm downfield from tetramethylsilane was observed in 13C difference spectra obtained at both 25.2 and 45.3 MHz.Chemical shift studies of several model compounds suggest that this is the resonance position to be expected for an acetamide group exposed to solvent.The line width observed for the enriched methyl resonance is consistent with free rotation of the methyl group.
- Gerig, J. T.,Katz, K. E.,Reinheimer, J. D.,Sullivan, Glenn R.,Roberts, John D.
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- Ferrocene-biotin conjugates targeting cancer cells: Synthesis, interaction with avidin, cytotoxic properties and the crystal structure of the complex of avidin with a biotin-linker-ferrocene conjugate
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Friedel-Crafts acylation of ferrocene with a biotin-derived carboxylic acid having 6-aminohexanoyl linkers attached to the biotin carboxylic group and with desthiobiotin afforded the corresponding ferrocene-biotin bioconjugates. These compounds as well as biotinyl ferrocenyl ketone exhibit high affinity for avidin. Their cytotoxicity against cancer cell lines having various levels of biotin receptors (SMVT) was measured and revealed that lines displaying high levels of SMVT (SW620) were the most susceptible. This suggests that biotin serves as a biological vector delivering cytotoxic ferrocenyl moieties to cancer cells. The crystal structure of the complex of avidin with a conjugate having two linker units between biotin and ferrocene was determined and revealed stabilization of several different conformations of the ligand within the protein binding pocket.
- Plaziuk, Damian,Zakrzewski, Janusz,Salmain, Michele,Blauzi, Andrzej,Rychlik, Blaziej,Strzelczyk, Pawel,Bujacz, Anna,Bujacz, Grzegorz
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Read Online
- CXCR4-TARGETED DIAGNOSTIC AND THERAPEUTIC AGENTS WITH REDUCED SPECIES SELECTIVITY
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The present disclosure relates to imaging and endoradiotherapy of diseases involving chemokine receptor 4 (CXCR4). Provided are compounds which bind or inhibit hCXCR4 and mCXCR4 and furthermore carry at least one moiety which is amenable to labeling. Provided are also medical uses of such compounds.
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Page/Page column 64
(2020/05/07)
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- Method for synthesizing hexanediamine by taking caprolactam as raw material
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The invention discloses a method for synthesizing hexanediamine by taking caprolactam as a raw material. The method comprises the following steps that (1) after the hexanediamine, alkali and water aremixed, heating reflux is conducted, and thus 6-amino-caproate is obtained; (2) the 6-amino-hexanoate obtained in the step (1) is introduced into an amino protecting group to protect an amino end group, then acid is added for neutralization to generate aminocaproic acid with the amino protecting group; (3) after a product obtained in the step (2) is dried, a dehydration catalyst for amide is added, a heating reaction is conducted in the presence of an ammonia source to convert a carboxylic acid group into a cyano group, and thus product nitrile is obtained; and (4) after the product nitrile obtained in the step (3) is extracted and purified, catalytic hydrogenation is conducted to generate corresponding amine, then the protecting group is removed, and thus a target product can be obtained.
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Paragraph 0030; 0033; 0034; 0048; 0051; 0052
(2019/11/21)
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- Generation of amine dehydrogenases with increased catalytic performance and substrate scope from ε-deaminating L-Lysine dehydrogenase
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Amine dehydrogenases (AmDHs) catalyse the conversion of ketones into enantiomerically pure amines at the sole expense of ammonia and hydride source. Guided by structural information from computational models, we create AmDHs that can convert pharmaceutically relevant aromatic ketones with conversions up to quantitative and perfect chemical and optical purities. These AmDHs are created from an unconventional enzyme scaffold that apparently does not operate any asymmetric transformation in its natural reaction. Additionally, the best variant (LE-AmDH-v1) displays a unique substrate-dependent switch of enantioselectivity, affording S- or R-configured amine products with up to >99.9% enantiomeric excess. These findings are explained by in silico studies. LE-AmDH-v1 is highly thermostable (Tm of 69 °C), retains almost entirely its catalytic activity upon incubation up to 50 °C for several days, and operates preferentially at 50 °C and pH 9.0. This study also demonstrates that product inhibition can be a critical factor in AmDH-catalysed reductive amination.
- Tseliou, Vasilis,Knaus, Tanja,Masman, Marcelo F.,Corrado, Maria L.,Mutti, Francesco G.
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- Energetic contribution to both acidity and conformational stability in peptide models
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The acidity of N-acyl amino acids is dependent upon the rotameric state of the amide bond. In this work we systematically investigated the acidity difference of the rotamers (ΔpKa) in the frames of various acetylated amino acids. Our results indicated a mutual interaction of two carbonyl groups of an attractive type. We observed conservative ΔpKas for acyclic amino acids (2.2-3.0 kJ mol-1), whereas in the case of alicyclic amino acids, the experimental values revealed a strong dependency on the structural context (1.5-4.4 kJ mol-1). In homologous amino acids (α-, β-, γ-, etc.), the strength of the attraction decays in an exponential fashion. Furthermore, the interaction can accumulate through a chain of amide bonds in a cascade fashion, as demonstrated by an Ac-Pro-Pro dipeptide. As a result, we demonstrate that ΔpKa is an experimental parameter to estimate increments in the carbonyl-carbonyl alignment, as determined by the amino acid or peptidyl context. This parameter is also important in understanding the roles of amino acids in both protein folding and translation in biological systems as well as their evolutionary appearance in the genetic code.
- Kubyshkin, Vladimir,Durkin, Patrick,Budisa, Nediljko
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supporting information
p. 5209 - 5220
(2016/07/06)
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- PRODUCTION OF CAPROLACTAM FROM CARBOHYDRATE-CONTAINING MATERIALS
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The present invention generally relates to processes for the conversion of glucose to caprolactam employing chemocatalytic oxidation and reduction reactions. The present invention also includes processes for the conversion of glucose to caprolactam via amido polyhydroxy acid products and amidocaproic acid or derivatives thereof. The present invention also includes processes that catalytically oxidize an amidopolyol to amidopolyhydroxy acid or derivatives thereof, and processes that catalytically hydrodeoxygenate amino or amido polyhydroxy acid or derivatives thereof to an amino or amidocaproic acid product. The amino or amidocaproic acid product may then be converted to caprolactam. The present invention also includes products produced by such processes and products producable from such products.
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Page/Page column 12
(2012/10/23)
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- HOBT immobilized on macroporous polystyrene beads: A useful reagent for the synthesis of amides
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Polymer-supported 1-hydroxybenzotriazole (P-HOBT), prepared from macroporous polystyrene beads, was used to synthesize amides from primary and secondary amines.
- Dendrinos, Kleanthis,Jeong, Jeannie,Huang, Wei,Kalivretenos, Aristotle G.
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p. 499 - 500
(2007/10/03)
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- Composition containing a penem or carbapenem antibiotic and the use of the same
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Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially.
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- Composition containing a penem or carbapenem antibiotic
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Administration of an N-acylated amino acid in association with a penem or carbapenem antibiotic relieves or eliminates the renal problems associated with administration of the antibiotic alone. The amino acid derivative and antibiotic may be formulated together as a composition or administered separately, either simultaneously or sequentially. The composition may be prepared by simple mixing.
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