1676-73-9Relevant academic research and scientific papers
Novel thermo- and pH-responsive hydroxypropyl cellulose- and poly (l-glutamic acid)-based microgels for oral insulin controlled release
Bai, Yunyan,Zhang, Zhe,Zhang, Aiping,Chen, Li,He, Chaoliang,Zhuang, Xiuli,Chen, Xuesi
, p. 1207 - 1214 (2012)
Novel smart microgel particles made of poly (l-glutamic acid-2-hydroxylethyl methacrylate) (PGH) and hydroxypropyl cellulose-acrylic acid (HPC-AA) have been successfully prepared via emulsion polymerization. The dynamic light scattering measurement reveals that the average hydrodynamic radius 〈Rh〉 and hydrodynamic radius distributions f (R h) of the microgel particles depend on the temperature and pH value thus the microgel particles exhibit both pH- and temperature-sensitivity. In vitro release study shows that the amount of insulin released from microgels in the gastric juice (at pH 1.2) is significantly less than that in the intestinal fluid (at pH 6.8). These results indicate that the resultant microgels are of potential for use in intelligent oral drug delivery systems.
The Synthesis of β-Benzyl L-Aspartate and γ-Benzyl L-Glutamate by Enzyme-Catalyzed Hydrolysis
Chen, Shui-Tein,Wang, Kung-Tsung
, p. 581 - 582 (1987)
The enzyme-catalyzed hydrolysis of dibenzyl ester of aspartic acid and glutamic acid in α-position to give better yield of β-benzyl aspartate and γ-benzyl glutamate than the chemical method is reported.
BOROXAZOLIDONES AS SIMULTANEOUS PROTECTION OF THE AMINO AND CARBOXYL GROUP IN α-AMINO ACIDS
Nefkens, G. H. L.,Zwanenburg, B.
, p. 2995 - 2998 (1983)
The synthesis of boroxazolidones 1 from a variety of α-amino acids is given.These compounds 1 show a strong intramolecular coordination between B and the amino group.These heterocycles can serve as protected α-amino acids in which the α-amino and the carboxyl function are simultaneously blocked, while the side chain remains free for further reactions.The boroxazolidines were reconverted into α-amino acids under mild acid conditions.Using this methodology aspartic acid was converted into β-benzyl aspartate and glutamic acid into γ-benzyl glutamate.
Cellular uptake and transfection activity of DNA complexes based on poly(ethylene glycol)-poly(l-glutamine) copolymer with PAMAM G2
Pan, Shirong,Cao, Duanwen,Fang, Rong,Yi, Wu,Huang, Huan,Tian, Shouqin,Feng, Min
, p. 5114 - 5127 (2013)
Poly(ethylene glycol)-poly(l-glutamine) (PEG-PLGA) copolymer EA-G2 (or EA-G1) was prepared by aminolysis of poly(ethylene glycol)-poly(l-benzyl glutamate) (PEG-PBLG) using PAMAM G2 (or G1). The chemical structure of PEG-PLGA was confirmed by FT-IR, 1H-NMR, DSC and GPC. The performances of the EA-G2 (or EA-G1) were assayed by enzyme degradation, MTT method and agarose gel electrophoresis. The particle size, zeta potential and morphology of EA-G2 (or EA-G1)/pDNA complexes were inspected by DLS and AFM. The cellular uptake mechanism was evaluated by endocytic inhibiting test, cell uptake test and observation of CLSM. The transfection activity was measured by flow cytometry. The EA-G2 (or EA-G1) exhibited good biodegradability, low cytotoxicity and great ability to combine with pDNA. The EA-G2 (or EA-G1) complexes exhibited particle sizes in the range 120-180 nm and zeta potentials in the range 20-40 mV, which were suitable for cell uptake. The cellular uptake of the EA-G2 complexes occurred mainly through clathrin-dependent and caveolin-mediated endocytosis, and at 6 h in 10% FBS and in serum-free media, the percentages of complex uptake reached 89.0% or 72.7%, respectively. EA-G2 complexes could efficiently mediate pEGFP-Cl into the cell nuclei. EA-G2 complexes displayed enhancing transfection efficiency and better serum tolerance. The results suggest that the EA-G2 has potential to be used as a biodegradable, efficient and serum-resistant gene vector.
Synthesis and self-assembly of thermoresponsive amphiphilic biodegradable polypeptide/poly(ethyl ethylene phosphate) block copolymers
Wu, Qiuhua,Zhou, Dan,Kang, Renyu,Tang, Xiuping,Yang, Qi,Song, Ximing,Zhang, Guolin
, p. 2850 - 2858 (2014)
We report the design and synthesis of new fully biodegradable thermoresponsive amphiphilic poly(γ-benzyl L-glutamate)/poly(ethyl ethylene phosphate) (PBLG-b-PEEP) block copolymers by ring-opening polymerization of N-carboxy-γ-benzyl L-glutamate anhydride (BLG-NCA) with amine-terminated poly(ethyl ethylene phosphate) (H2N-PEEP) as a macroinitiator. The fluorescence technique demonstrated that the block copolymers could form micelles composed of a hydrophobic core and a hydrophilic shell in aqueous solution. The morphology of the micelles as determined by transmission electron microscopy (TEM) was spherical. The size and critical micelle concentration (CMC) values of the micelles showed a decreasing trend as the PBLG segment increased. However, UV/Vis measurements showed that these block copolymers exhibited a reproducible temperature-responsive behavior with a lower critical solution temperature (LCST) that could be tuned by the block composition and the concentration.
Orientational properties of poly-γ-benzyl-L-glutamate: Influence of molecular weight and solvent on order parameters of the solute
Marx, Andreas,Thiele, Christina
, p. 254 - 260 (2009)
Residual dipolar couplings (RDCs) have recently become increasingly important in organic structure determination due to their unique information content. One main limitation for the use of RDCs in organic compounds, however, is that the compound in question needs to be oriented with respect to the magnetic field in order to measure RDCs. So far, there are very few possibilities for modulating the induced degree of orientation. The situation is even worse when chiral orienting media are considered, which could allow absolute configuration determination in the future. We have conducted a systematic investigation into modulating the orientation induced by one chiral orienting medium, namely organic solutions of PBLG (poly-γ-benzyl-L- glutamate), as a function of its molecular weight and the organic co-solvent used, and have obtained significant insights into factors that influence the order induced. With increasing molecular weight of the polypeptide the orientation of the solutes decreases, leading to well-resolved spectra with improved line shapes. This can be attributed exclusively to the fact that the critical concentration of the liquid-crystalline phase decreases with increasing molecular weight (pure dilution effect). Any influence of increasing flexibility on the orientation can be ruled out.
Highly stable polyglutamate derivatives/siRNA polyplex efficiently down-relegate survivin expression and augment the efficacy of cisplatin
Wang, Zhongjuan,Zou, Haijuan,Wang, Zirui,Wu, Jiamin,Xia, Zhongsheng,Feng, Min
, p. 24 - 34 (2016)
RNA interfere (RNAi)-based technology holds great promise in cancer treatment. The use of small interfering RNA (siRNA), however, is hampered by its low delivery efficiency in vivo when they are diluted in blood biofluids and in the presence of serum and salt. In this study, we developed the polyglutamate derivative polymer brush, poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (mPEG-b-PG-g-spermine, PPGS), which could efficiently deliver survivin-siRNA under ultra-high dilution and in the presence of salt (NaCl 150 mM) and serum (10% FBS), most likely due to its PEG-shelled polymer brush structure. On the contrary, aggregation occurred when PEI/siRNA polyplex dispersed in saline and serum-containing media and PEI polyplex dissociated after making a 256-fold dilution. PPGS/si-survivin polyplex exhibited high cellular uptake efficiency and efficiently down-regulated the expression of survivin mRNA in the cisplatin-resistance of non-small cell human lung adenocarcinoma (A549/DDP) cells in the presence of serum. However, either PEI polyplex or Lipofectmine 2000 complex was unstable in serum and salt-containing media and at high dilution rates, which resulted in their dramatical decrease of cellular uptake and gene-silencing efficiency in these conditions. The PPGS/si-survivin polyplex also exhibited synergistic effects of killing the cancer cells by combination treatment with cisplatin. Therefore, the PPGS gene carrier showed great potential in systemic siRNA delivery, and its combination with chemotherapeutic drug is promising in treating drug resistant cancers.
Microwave assisted synthesis and antimicrobial study of Schiff base vanadium(IV) complexes of phenyl esters of amino acids
Wazalwar, Sachin S.,Bhave, Narayan S.,Dikundwar, Amol G.,Ali, Parvez
, p. 459 - 464 (2011)
Schiff base vanadium(IV) complexes of phenyl esters of the two acidic amino acids, i.e., aspartic and glutamic acid, were synthesized. The phenyl esters of these amino acids were synthesized by conventional method whereas the Schiff base vanadium(IV) complexes were synthesized using microwave irradiation. The complexes were characterized by spectroscopic tools such as IR, 1H NMR, mass (ES), ESR, and UV visible spectroscopy. All the complexes were studied for antibacterial and antifungal activity and found to be moderately active. Copyright Taylor & Francis Group, LLC.
Design, synthesis, and biological evaluation of desmuramyl dipeptides modified by adamantyl-1,2,3-triazole
?kalamera, Dani,Antica, Mariastefania,Car, ?eljka,Dra?enovi?, Josip,Milkovi?, Lidija,Perokovi?, Vesna Petrovi?,Ribi?, Rosana,Stojkovi?, Ranko,Tomi?, Sr?anka
supporting information, (2021/11/01)
Muramyl dipeptide (MDP) is the smallest peptidoglycan fragment able to trigger the immune response. Structural modification of MDP can lead to the preparation of analogs with improved immunostimulant properties, including desmuramyl peptides (DMPs). The aim of this work was to prepare the desmuramyl peptide (L-Ala-D-Glu)-containing adamantyl-triazole moiety and its mannosylated derivative in order to study their immunomodulatory activities in vivo. The adjuvant activity of the prepared compounds was evaluated in a murine model using ovalbumin as an antigen, and compared to the reference adjuvant ManAdDMP. The results showed that the introduction of the lipophilic adamantyl-triazole moiety at the C-terminus of L-Ala-D-Glu contributes to the immunostimulant activity of DMP, and that mannosylation of DMP modified with adamantyl-triazole causes the amplification of its immunostimulant activity.
Preparation method of N-fluorenylmethoxycarbonyl-gamma-(S-triphenylmethyl-cysteamine)-L-glutamic acid
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Paragraph 0061, (2020/10/05)
The invention provides a preparation method of N-fluorenylmethoxycarbonyl-gamma-(S-triphenylmethyl-cysteamine)-L-glutamic acid. The preparation method mainly solves the technical problems of complexity, long period, high cost, and low yield of an original process, and comprises the following steps: (1) preparing N-fluorenylmethoxycarbonyl-L-glutamic acid; (2) preparing N-fluorenylmethoxycarbonyl-L-glutamic acid-1-benzyl ester; (3) preparing S-triphenylmethyl cysteamine; (4) preparing N-fluorenylmethoxycarbonyl-gamma-(S-triphenylmethyl-cysteamine)-L-glutamic acid-alpha-benzyl ester; and (5) preparing N-fluorenylmethoxycarbonyl-gamma-(S-triphenylmethyl-cysteamine)-L-glutamic acid. The method is rapid, high in yield and simple in separation and purification, and the used solvent is environment-friendly and is suitable for mass production.
