ChemInform Abstract: Surface‐Mediated Reactions. Part 9. Selective Oxidation of Primary and Secondary Amines to Hydroxylamines.

Fields, John D.; Kropp, Paul J.

doi:10.1002/chin.200105061

Cited by 2 publications

(2 citation statements)

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“…28 However, we found hydroxylamine 9 was very susceptible to further oxidation with mCPBA. 29 As evidenced by many side product spots on the TLC plate and M -1, M, and M + 1 peaks in the mass spectrum, we concluded that the mCPBA oxidation reaction was complicated by overoxidation. Varying the mCPBA ratio and the reaction temperature did not help circumvent the problem.…”

Section: Chemistrymentioning

confidence: 77%

Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Seo

Igarashi

et al. 2007

J. Med. Chem.

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The neuronal isoform of nitric oxide synthase (nNOS), the enzyme responsible for the production of nitric oxide in the central nervous system, represents an attractive target for the treatment of various neurodegenerative disorders. X-ray crystal structures of complexes of nNOS with two nNOSselective inhibitors, (4S)-N-{4-amino-5-[(2-aminoethylamino]pentyl}-N′-nitroguanidine (1) and 4-N-(N ω -nitro-L-argininyl)-trans-4-amino-L-proline amide (2), led to the discovery of a conserved structural water molecule that was hydrogen bonded between the two heme propionates and the inhibitors (Figure 2). Based on this observation, we hypothesized that by attaching a hydrogen bond donor group to the amide nitrogen of 2 or to the secondary amine nitrogen of 1, the inhibitor molecules could displace the structural water molecule and obtain a direct interaction with the heme cofactor. To test this hypothesis, peptidomimetic analogues 3-5, which have either an N-hydroxyl (3 and 5) or N-amino (4) donor group, were designed and synthesized. X-ray crystal structures of nNOS with inhibitors 3 and 5 bound verified that the N-hydroxyl group had, indeed, displaced the structural water molecule and provided a direct interaction with the heme propionate moiety (Figures 4 and 5). Surprisingly, in vitro activity assay results indicated that the addition of a hydroxyl group (3) only increased the potency slightly against the neuronal isoform over the parent compound (1). Rationalizations for the small increase in potency are consistent with other changes in the crystal structures.

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Section: Chemistrymentioning

confidence: 77%

Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Seo

Igarashi

et al. 2007

J. Med. Chem.

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“…8 The latter is finally dehydrated to form an imine. 8,9 These changes not only alter the structural and physicochemical properties of the membrane but also cause chlorination degradation of the PA selective layer, eventually leading to the loss of membrane selectivity in separation. 8,10 Therefore, exploring novel PA membranes with excellent chlorine resistance has become a research focus recently.…”

Section: Introductionmentioning

confidence: 99%

Construction and Chlorine Resistance of Thiophene-Poly(ethyleneimine)-Based Dual-Functional Nanofiltration Membranes

Cheng

Meng

2023

ACS Appl. Mater. Interfaces

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The demand to improve the chlorine resistance of polyamide (PA) membranes is escalated with greater amounts of chlorine-containing disinfectant being used in global water treatment during the COVID-19 pandemic. In this work, we designed thiophene-functionalized poly(ethyleneimine) (TPEI) materials first and grafted them onto a conventional PA membrane to develop novel nanofiltration membranes (PEI-M, TPEI-1-M, TPEI-2-M). These membranes have dual-functionalized selective surfaces covered by hydrophilic amino groups and electron-rich thiophene moieties, which endow these membranes with superior chlorine resistance and improved separation performance. The modified membranes increase the rejection of MgCl2 from 86.5% of the nascent PA membrane (PA-M) to higher than 93.0% without sacrificing the membrane water permeability. More stable separation performance is achieved with all of the as-prepared membranes than PA-M after exposure to a 2000 ppm sodium hypochlorite solution. TPEI-2-M outperforms other membranes after being treated in a chlorination intensity of 16,000 ppm·h with the smallest flux loss and the highest MgCl2 rejection. This is mainly ascribed to the highest amount of amino and thiophene moieties on the TPEI-2-M surface. This study provides an effective protocol for developing novel PA-based nanofiltration membranes while demonstrating its superiority over current technologies with exceptional separation performance and antichlorine ability.

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ChemInform Abstract: Surface‐Mediated Reactions. Part 9. Selective Oxidation of Primary and Secondary Amines to Hydroxylamines.

Cited by 2 publications

References 1 publication

Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Construction and Chlorine Resistance of Thiophene-Poly(ethyleneimine)-Based Dual-Functional Nanofiltration Membranes

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ChemInform Abstract: Surface‐Mediated Reactions. Part 9. Selective Oxidation of Primary and Secondary Amines to Hydroxylamines.

Cited by 2 publications

References 1 publication

Structure-Based Design and Synthesis ofNω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Structure-Based Design and Synthesis ofNω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Construction and Chlorine Resistance of Thiophene-Poly(ethyleneimine)-Based Dual-Functional Nanofiltration Membranes

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Product

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Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water

Structure-Based Design and Synthesis ofN^ω-Nitro-l-Arginine-Containing Peptidomimetics as Selective Inhibitors of Neuronal Nitric Oxide Synthase. Displacement of the Heme Structural Water