- Investigations of the Alignment Process of PBPMLG: 2H NMR Analysis Reveals a Thermoresponsive 90° Flip of the Polymer
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The application of anisotropic parameters in NMR-spectroscopy enables the acquisition of spatial and angular information, complementary to those from conventional isotropic NMR-measurements. The use of alignment media is a well-established method for inducing anisotropy. PBPMLG is a recently discovered polyglutamate-based alignment medium, exhibiting thermoresponsive behavior in the lyotropic liquid crystalline (LLC) phase, thus offering potential for deeper understanding of the alignment process. We present one approach for investigating the thermoresponsive behavior by synthesizing specifically deuterated PBPMLG-isotopologues and their subsequent analyses using 2H NMR-spectroscopy. It was possible to relate the observed thermoresponsive behavior to a flip of the polymer with respect to the external magnetic field—an effect never observed before in glutamate-based polymeric alignment media. Furthermore, a solvent-induced temperature dependent gelation was verified in THF, which might provide yet another opportunity to manipulate the properties of this alignment medium in the future.
- Schirra, Dominic S.,Hirschmann, Max,Radulov, Iliya A.,Lehmann, Matthias,Thiele, Christina M.
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supporting information
p. 21040 - 21046
(2021/08/23)
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- Synthesis method of phthalic acylamino-L-glutamic anhydride
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The invention discloses a synthesis method of phthalic acylamino-L-glutamic anhydride. The method comprises the following steps: firstly, ensuring that phthalic anhydride and L-glumatic acid react for4 to 8 hours at 80 to 85 DEG C with the existence of an acid-binding agent, and adjusting pH with hydrochloric acid till N-phthaloyl-L-glutamic acid is separated out; secondly, adding acetic anhydride to the N-phthaloyl-L-glutamic acid obtained in the first step, performing reflux reaction, naturally cooling to room temperature, ensuring that white solid is separated out, separating, and drying,so as to obtain the phthalic acylamino-L-glutamic anhydride. The synthesis method is short in route, easy to operate, high in yield, low in pollution, and more environmentally friendly, ensures that the production cost is greatly reduced, and has a good application prospect.
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Paragraph 0024-0026; 0030-0032; 0035-0037
(2019/03/29)
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- Light-Triggered Transformation of Molecular Baskets into Organic Nanoparticles
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Discovering novel and functional photoresponsive materials is of interest for improving controlled release of molecules and scavenging toxic compounds for cleaning our environment or designing chemosensors. In this study, we report on the photoinduced decarboxylation of basket 16?, containing three glutamic acids at its rim. This concave compound is, in an aqueous environment (30 mm phosphate buffer at pH 7.0), monomeric (1H NMR DOSY, DLS) with glutamic acid residues randomly oriented about its rim (1H NMR and MM-OPLS3). The irradiation (300 nm) of 16? leads to the exclusive removal of its α-carboxylates to give amphiphilic 23? possessing γ-carboxylates. The photochemical transformation is a consecutive reaction with mono- and bis-decarboxylated products observed with 1H NMR spectroscopy and ESI mass spectrometry. Amphiphilic 23? is a preorganized molecule (MM-OPLS3) that, in water, aggregates into organic nanoparticles (ca. 50–200 nm in diameter; DLS, TEM and cryo-TEM) having a critical aggregation concentration of 12 μm (UV/Vis). As the transition of monomeric 16? into nanoparticulate 23? is triggered with light, we reasoned that stimuli-responsive formation of the soft material lends itself to nanotechnology applications such as controlled release or scavenging of targeted compounds.
- Border, Sarah E.,Pavlovi?, Radoslav Z.,Zhiquan, Lei,Gunther, Michael J.,Wang, Han,Cui, Honggang,Badji?, Jovica D.
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p. 273 - 279
(2018/10/24)
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- Poly-γ-p-Biphenylmethyl-Glutamate as Enantiodifferentiating Alignment Medium for NMR Spectroscopy with Temperature-Tunable Properties
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The use of anisotropic NMR parameters—especially residual dipolar couplings (RDCs)—offers access to additional structural information and, therefore, alignment media required for this approach are under a continuous development. Here, we present poly-γ-p-biphenylmethyl-glutamate (PBPMG) as a new versatile enantiodifferentiating alignment medium. The thermoresponsive properties of this polymer allowed for RDC measurements of more than one orientation within the same sample at different temperatures. Moreover, the outstanding enantiodifferentiation along with excellent spectral quality even offered the opportunity to differentiate enantiomers in mixtures.
- Jeziorowski, Sharon,Thiele, Christina M.
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supporting information
p. 15631 - 15637
(2018/09/27)
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- A Genetically Encoded Allysine for the Synthesis of Proteins with Site-Specific Lysine Dimethylation
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Using the amber suppression approach, N?-(4-azidobenzoxycarbonyl)-δ,?-dehydrolysine, an allysine precursor is genetically encoded in E. coli. Its genetic incorporation followed by two sequential biocompatible reactions allows convenient synthesis of proteins with site-specific lysine dimethylation. Using this approach, dimethyl-histone H3 and p53 proteins have been synthesized and used to probe functions of epigenetic enzymes including histone demethylase LSD1 and histone acetyltransferase Tip60. We confirmed that LSD1 is catalytically active toward H3K4me2 and H3K9me2 but inert toward H3K36me2, and methylation at p53 K372 directly activates Tip60 for its catalyzed acetylation at p53 K120.
- Wang, Zhipeng A.,Zeng, Yu,Kurra, Yadagiri,Wang, Xin,Tharp, Jeffery M.,Vatansever, Erol C.,Hsu, Willie W.,Dai, Susie,Fang, Xinqiang,Liu, Wenshe R.
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supporting information
p. 212 - 216
(2016/12/30)
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- Phthaloyl amino acids as anti-inflammatory and immunomodulatory prototypes
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A series of phthalimide analogs were synthesized by derivatization of phthalic anhydride, a highly toxic substance, using a "one pot" condensation reaction to α-amino acids. All phthaloyl amino acid derivatives presented anti-oral inflammatory activity, but compounds 2e and 2g were found to possess the best activities comparable to thalidomide.Most of the compounds effectively suppressed nitric oxide production inmurine cells stimulatedwith lipopolysaccharide. N-phthaloyl amino acids did not exhibit any significant cytotoxicity in vitro when tested against tumor cells as well as a spleen cell culture of BALB/c mice. Compounds 2a, 2g, and 2h were able to inhibit TNF-α and IL-1β production by macrophages. At the same concentration, thalidomide did not exhibit significant inhibitory activity. Springer Science+Business Media 2013.
- Leite, Ana Cristina Lima,Barbosa, Fabio Fernandes,Cardoso, Marcos Verissimo De Oliveira,Moreira, Diogo R. M.,Coelho, Lucas Cunha D.,Da Silva, Elany Barbosa,Filho, Gevanio Bezerra De Oliveira,De Souza, Valdenia Maria Oliveira,Pereira, Valeria Rego A.,Reis, Luiza De C.,Ferreira, Paulo Michel Pinheiro,Pessoa, Claudia,Wanderley, Almir Goncalves,Mota, Fernanda Virginia B.,Da Silva, Teresinha G.
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p. 1701 - 1708
(2014/05/06)
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- The c(RGDyK)-Conjugated Fe3O4 nanoparticles with high drug load for dual-targeting integrin αvβ3- expressing cancer cells
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A novel drug delivery system c(RGDyK)-modified Fe3O4 nanoparticles with high DOX load (R-DMP), which combines magnetic targeting, integrin αvβ3 targeting and high drug loading properties, was developed by chemical coupling both doxorubicin and peptide c(RGDyK) on the synthetic dual function magnetic nanoparticles (DMP) using a multi-hand cross-linker poly-L-glutamic acid. R-DMP has high drug loading ratio and trapping efficiency for magnetic targeting, and the drug loading ratio can be controlled by adjusting the reactant ratio. Moreover, R-DMP presents narrow size distribution and is sensitive to pH for drug releasing. Compare with those of doxorubicin coupled DMP without peptide c(RGDyK) modification, D-DMP shows enhanced uptake by integrin αvβ3 targeting expressing tumor cells and displays stronger cancer cell cytotoxicity. This investigate provides a new approach for the dual-targeted delivery of therapeutic agents to tumors with controlled low carrier toxicity and high efficiency. Copyright
- Guo, Lin,Ding, Wence,Zheng, Li-Min
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p. 4858 - 4864
(2014/07/21)
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- Synthesis of amphiphilic alternating polyesters with oligo(ethylene glycol) side chains and potential use for sustained release drug delivery
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Novel amphiphilic alternating polyesters, poly((N-phthaloyl-l-glutamic anhydride)-co-(2-(2-(2-methoxyethoxy)ethoxy)methyl)oxirane) (P(PGA-co-ME 2MO)), were synthesized by alternating copolymerization of PGA and ME2MO. The structures of the synthesized polyesters were characterized by 1H NMR, 13C NMR, FT-IR, and GPC analyses. Because of the presence of oligo(ethylene glycol) (OEG) side chains, the polyesters could self-assemble into thermosensitive micelles. Dynamic light scattering (DLS) showed that these micelles underwent thermoinduced size decrease without intermicellar aggregation. In vitro methyl thiazolyl tetrazolium (MTT) assay demonstrated that the polyesters were biocompatible to Henrietta Lacks (HeLa) cells, rendering their potential for drug delivery applications. Two hydrophobic drugs, rifampin and doxorubicin (DOX), were loaded into the polyester micelles and observed to be released in a zero-order sustained manner. The sustained release could be accelerated in lower pH or in the presence of proteinase K, due to the degradation of the polyester under these conditions. Remarkably, in vitro cell experiments showed that the polyester micelles accomplished fast release of DOX inside cells and higher anticancer efficacy as compared with the free DOX. With enhanced stability during circulation condition and accelerated drug release at the target sites (e.g., low pH or enzyme presence), these novel polyesters with amphiphilic structures are promising to be used in sustained release drug delivery systems.
- Wang, Wei,Ding, Jianxun,Xiao, Chunsheng,Tang, Zhaohui,Li, Di,Chen, Jie,Zhuang, Xiuli,Chen, Xuesi
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experimental part
p. 2466 - 2474
(2012/04/23)
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- Novel Dipeptides incorporating selenoamino acids with enhanced bioavailability- Synthesis, pharmaceutical and cosmeceutical applications thereof
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Disclosed is a novel synthetic method for isomeric peptides through an appropriate linkage of L-selenomethionine or Se-Methyl-L-selenocysteine with L-glutamic acid. The novel synthetic method produces isomeric peptides of L-selenomethionine or Se-Methyl-L-selenocysteine that exhibit (i) enhanced water solubility; (ii) enhanced rate of dissolution in water; (iii) enhanced bioavailability; (iv) excellent vascular endothelial growth factor promoting activity; (v) excellent anti-5-alpha-reductase activity; (vi) capabilities to prevent/reduce “hair fall” and promote “hair growth”, thereby maintaining a perfect homeostasis for “hair care”. Cosmeceutical and pharmaceutical compositions comprising the isomeric peptides obtained through an appropriate linkage of L-selenomethionine or Se-Methyl-L-selenocysteine with L-glutamic acid are also disclosed. Other dipeptides with several other amino acids and uses thereof are also disclosed.
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Page/Page column 6
(2010/11/29)
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- A practical and efficient synthesis of thalidomide via Na/liquid NH 3 methodology
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A facile, efficient, concise, cost-effective, and scalable synthesis of thalidomide in high overall yield (55%) is presented. Treatment of Boc-protected L-glutamic acid diester via Na/ liquid (liq.) NH3 (-33°C) mediated cyclization methodology produces a corresponding glutarimide ring which was subsequently condensed with phthalic anhydride in the presence of glacial acetic acid to afford thalidomide.
- Varala, Ravi,Adapa, Srinivas R.
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supporting information
p. 853 - 856
(2012/12/26)
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- 3-Chloro-3-(dimethoxyphosphoryl)isobenzofuran-l(3h)-one - a new reagent for the rapid, convenient phthaloylation of amines and amino acids in high yields
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3-Chloro-3-(dimethoxyphosphoryl)isobenzofuran-l(3fl)one (1) reacts rapidly with aliphatic amines and with amino acids at room temperature to give phthalimides in high yields.
- Kehler, Jan,Breuer, Eli
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p. 1419 - 1420
(2007/10/03)
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- Synthesis of Medium- and Large-Ring Compounds Initiated by Photochemical Decarboxylation of ω-Phthalimidoalkanoates
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The synthesis of a variety of hydroxylactams from ω-phthalimidoalkanoates using a triplet-sensitized photodecarboxylation reaction initiated by intramolecular photo electron transfer is described. Ring sizes available by this method span from 4 (benzazepine-1,5-dione 7) to 26 (cyclodipeptide 26e). Ground-state template formation is proposed as the explanation for the high efficiency of this reaction and for the decrease in reactivity in the presence of organic bases instead of metal carbonates. The crucial step in this macrocyclization reaction seems to be the protonation of the intermediary ketyl radiais (Scheme 4). Spacer groups investigated were alkyl chains (C3-C11: 5c-h, 11a, 12), ether (16, 18), ester (20, 22), and amide (26a-f) linkages. Within the detection limits, no dimeric (= decarboxylative coupling) products were observed, indicating the high preference for intra-vs. intermolecular photoelectron transfer. The C,C radical combination step proceeds with low stereoselectivity (cf. products 11 and 12) in contrast to comparable singlet reactions. Except for the lactones 22, all products were stable under the photolysis conditions. Prolonged irradiation of 22 led to the formation of the spiro compounds 23, probably via an intermediary acyliminium betaine (Scheme 8). One serious limitation of the decarboxylative macrocyclization is its incompatibility with the glycine spacer (as in 27a and 27b), probably the consequence of a strong intramolecular H-bond (Scheme 10).
- Griesbeck, Axel G.,Henz, Andreas,Kramer, Wolfgang,Lex, Johann,Nerowski, Frank,Oelgemoeller, Michael,Peters, Karl,Peters, Eva-Maria
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p. 912 - 933
(2007/10/03)
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