- Direct monitoring of biocatalytic deacetylation of amino acid substrates by1H NMR reveals fine details of substrate specificity
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Amino acids are key synthetic building blocks that can be prepared in an enantiopure form by biocatalytic methods. We show that thel-selective ornithine deacetylase ArgE catalyses hydrolysis of a wide-range ofN-acyl-amino acid substrates. This activity was revealed by1H NMR spectroscopy that monitored the appearance of the well resolved signal of the acetate product. Furthermore, the assay was used to probe the subtle structural selectivity of the biocatalyst using a substrate that could adopt different rotameric conformations.
- De Cesare, Silvia,McKenna, Catherine A.,Mulholland, Nicholas,Murray, Lorna,Bella, Juraj,Campopiano, Dominic J.
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supporting information
p. 4904 - 4909
(2021/06/16)
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- Identification of novel N-acetylcysteine derivatives for the treatment of hepatocellular injury
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New anti-hepatocellular injury drugs with better curative effects and fewer side effects are urgently needed at present. In this study, a series of novel N-acetylcysteine (NAC) derivatives were designed, synthesized and biologically evaluated for their anti-hepatocellular injury activities against two different cell models. In the biological evaluation against hydrogen peroxide (H2O2)-induced LO2 hepatocytes, half of the target compounds exhibited moderate to potent activities in improving the model cell viability, and two compounds (6a and 6b) displayed more potent activities in decreasing malondialdehyde (MDA) levels than the positive control NAC. In further 4-acetamidophenol (APAP)-induced LO2 cell experiment, compounds 6a and 6b could not only improve the cell viability but also significantly reduce the secretion of MDA. Additionally, compound 6a displayed excellent Caco-2 permeability and oral bioavailability in rats. All these experimental results suggested that compounds 6a and 6b could serve as potential lead molecules for further development of anti-hepatocellular injury drugs.
- Liu, Shourong,Zhao, Yanmei,He, Ruoyu,Kong, Limin,Xi, Jianjun,Sun, Jingjing,Shao, Yidan,Pan, Xuwang,Zhang, Jiankang,Zhuang, Rangxiao
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p. 2238 - 2247
(2017/12/26)
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- Carvacrol codrugs: A new approach in the antimicrobial plan
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Objective: The increasing prevalence of antibiotic-resistant bacterial infections led to identify alternative strategies for a novel therapeutic approach. In this study, we synthesized ten carvacrol codrugs - obtained linking the carvacrol hydroxyl group
- Cacciatore, Ivana,Di Giulio, Mara,Fornasari, Erika,Di Stefano, Antonio,Cerasa, Laura Serafina,Marinelli, Lisa,Turkez, Hasan,Di Campli, Emanuela,Di Bartolomeo, Soraya,Robuffo, Iole,Cellini, Luigina
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- Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers
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In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.
- Otto, Nicola,Opatz, Till
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supporting information; experimental part
p. 1105 - 1111
(2012/09/07)
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- Palatability of aquaculture feed
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A method for enhancing the palatability of aquaculture food, the method comprising treating the food with a compound of Formula I: wherein R1, R2, R3, and n are as defined herein, are disclosed.
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- Role of the distance to the S-donor center in the hydrolysis of amino acid esters, catalyzed by palladacycles
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The hydrolysis of N-acetyl-S-methylcysteine and N-acetylmethionine p-nitrophenyl esters, catalyzed by the dimeric palladacycle [Pd(C6H4-CH2NMe2)Cl]2, is described by the kinetic equation kap = k0 + kcat. The catalytic rate constants kcat are equal to 881 ± 96 and 45 ± 3 1 mol-1 s-1, respectively, for the S-methylcysteine and methionine esters at pH 8.0 (25°C). The equilibrium constant K1 for dissociation of the dimeric catalyst by the action of amino acid esters in chloroform at 25°C are equal to (2.9±0.3) × 103 and (3.0±0.6) × 104 1/mol, respectively. Thus the catalysts in the hydrolysis of N-acetyl-S-methylcysteine p-nitrophenyl ester is by an order of magnitude more effective, and the formation of catalytically active species is by an order of magnitude less effective than in the case of the methionine ester. This finding was explained in terms of intramolecular mechanism of hydrolysis with formation of a six-membered cyclic tetrahedral intermediate.
- Kurzeev,Kazankov,Ryabov
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p. 1330 - 1334
(2007/10/03)
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- The S-alkyl chain length as a determinant of the anti-leukemic activity of cysteine chloromethyl ketone compounds
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A series of cysteine chloromethyl ketone compounds with a systematic variation of the S-alkyl chain length have been synthesized in order to gauge the effect of the alkyl chain length on the cytotoxicity of these compounds against human acute lymphoblastic leukemia cells. Comparable activities were observed for compounds with S-alkyl chains ranging from pentyl to dodecyl, with the best being undecyl (IC50 = 1.7 μM) and dodecyl (IC50 = 2.0 μM) against B-lineage leukemia cells and hexyl (IC50 = 0.7 μM) against T-lineage leukemia cells. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Perrey, David A.,Scannell, Michael P.,Narla, Rama Krishna,Uckun, Fatih M.
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p. 551 - 552
(2007/10/03)
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- L-Methionine related 1-amino acids by acylase cleavage of their corresponding N-acetyl-DL-derivatives
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Acylase I from Aspergillus oryzae is an even more useful enzyme than suggested so far. Besides standard amino acids such as L-Met, L-Val and L-Phe, a number of additional sulfur- and selenium-containing amino acids can be obtained at useful reaction rates and in very high enantiomeric purity by kinetic resolution of the respective N-acetyl-DL-amino acids.
- Bommarius, Andreas S.,Drauz, Karlheinz,Guenther, Kurt,Knaup, Guenter,Schwarm, Michael
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p. 3197 - 3200
(2007/10/03)
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- Cobalt assisted cleavage of S-S bonds and a base-free synthesis of mercapturic acids
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Base free transformation of PhSSPh to sulfides, PhSR (R = alkyl, benzyl, allyl, acyl) and N-acetyl-L-cystine to mercapturic acids [AcNHCH(COOH)CH2SR, R = alkyl, benzyl, allyl, acyl] have been achieved using Zn/cat. CoCl2/organic halide in MeCN at room temperature.
- Chowdhury, Shantanu,Roy, Sujit
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p. 2149 - 2152
(2007/10/03)
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- gem-Nitronitroso dianion radicals R-C (NO2)(NO)2- formed in the reaction between sodium nitrite/ ascorbate and the sulfur compounds methionine, (methylthio)acetic acid and S-methylcysteine studied by EPR spectroscopy
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gem-Nitronitroso dianion radicals R-C?(NO2)(NO)2-(R = alkyl) are formed in the reaction between sodium nitrite and the sulfur compounds methionine, (methylthio) acetic acid and S-methylcysteine dissolved in acid-water solu
- Lagercrantz, Carl
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p. 113 - 117
(2007/10/03)
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- A general and accurate nmr determination of the enantiomeric purity of α-aminoacids and α-aminoacid derivatives
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Derivatization of α-aminoacids, α-aminoesters and α-aminolactones as N-acetyl derivatives allow the accurate NMR determination of the enantiomeric purity. In these conditions the major coordination site with a chiral shift reagent will correspond to the NMR observation site. Experimental factors leading to the highest ΔΔδ values are ascertained. No straightforward correlation with absolute configurations can be established.
- Calmes, Monique,Daunis, Jacques,Jacquier, Robert,Verducci, Jean
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p. 2285 - 2292
(2007/10/02)
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- Cysteine derivatives
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This invention relates to S-alkylcysteines and processes for preparing same. The compounds according to this invention are expected to be applicable as therapeutic agents for hepatic failures.
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