13726-76-6Relevant articles and documents
A biomimetic chitosan derivates: Preparation, characterization and transdermal enhancement studies of n-arginine chitosan
Lv, Hui-Xia,Zhang, Zhen-Hai,Wang, Xiao-Pan,Cheng, Qing-Qing,Wang, Wei,Huang, Xu-Hui,Zhou, Jian-Ping,Zhang, Qiang,Hou, Lu-Lu,Huo, Wei
, p. 6778 - 6790 (2011)
A novel arginine-rich chitosan (CS) derivates mimicked cell penetration peptides; N-Arginine chitosan (N-Arg-CS) was prepared by two reaction methods involving activated L-arginine and the amine group on the chitosan. FTIR spectra showed that arginine was chemically coupled with CS. Elemental analysis estimated that the degrees of substitution (DS) of arginine in CS were 6%, 31.3% and 61.5%, respectively. The drug adefovir was chosen as model and its permeation flux across excised mice skin was investigated using a Franz diffusion cell. The results showed that the most effective enhancer was 2% (w/v) concentration of 10 kDa N-Arg-CS with 6% DS. At neutral pH, the cumulative amount of adefovir permeated after 12 hours was 2.63 ± 0.19 mg cm -2 which was 5.83-fold more than adefovir aqueous solution. Meanwhile N-Arg-CS was 1.83, 2.22, and 2.45 times more effective than Azone, eucalyptus and peppermint, respectively. The obtained results suggest that N-Arg-CS could be a promising transdermal enhancer.
A study on effects of naphthalimide derivative-capped quantum dots on the cellular internalization, proliferation, and apoptosis ability
Zhao, Mei-Xia,Zeng, Er-Zao,Li, Yang,Wang, Chao-Jie
, p. 7351 - 7359 (2014)
Quantum dots (QDs) have shown great potential in monitoring and imaging cancer cells because of their unique photochemical and photophysical properties. However, it is little-known whether QDs affect the cellular internalization, proliferation and apoptosis. Here a new class of multifunctional QDs capped with ligands that possess l-Lys or l-Arg and naphthalimide (NI), linked by carboxyl groups (l-Lys-NI@QDs and l-Arg-NI@QDs, respectively), have been synthesized. We found that these QDs are of controllable sizes, in the range of 4 to 5 nm and have strong optical emission properties. The cellular uptake of NI derivative-capped QDs was monitored by flow cytometry and confocal microscopy. The results of in vitro cytotoxicity revealed that NI derivative-capped QDs, with better cell selectivity, could inhibit the growth of multiple cancer cells more potently than amonafide. They effectively inhibited the proliferation of cells due to apoptosis, which was confirmed by Hoechst 33342, annexin V-FITC and JC-1 staining and mitochondrial membrane potential (MMP) experiments. The most potent NI derivative-capped QDs, l-Arg-NI@CdSe/ZnS, were verified to efficiently induce apoptosis via a reactive oxygen species (ROS) mediating mitochondrial dysfunction, and were more effective in promoting programmed cell death in HepG2 cells in a preliminary mechanistic study. This journal is
The microenvironment and pKaperturbation of aminoacyl-tRNA guided the selection of cationic amino acids
Hazra, Bibhas,Prasad, Mahesh,Roy, Rajat,Tarafdar, Pradip K.
supporting information, p. 8049 - 8056 (2021/10/04)
The proteinogenic lysine (Lys) and arginine (Arg) have multiple methylene groups between α-carbon and the terminal charged centre. Why nature did not select ornithine (Orn), 2,4-diamino butyric acid (Dab) and 2,3-diamino propionic acid (Dpr) with fewer methylene groups in the side chain remains an important question! The propensity of aminoacyl-tRNA (aa-tRNA) model substrates towards self-degradationviaintramolecular lactamization was studied using UV spectroscopy and1H-NMR titration, which showed that Lys and Arg remain stable, and Orn and Dab cyclize to lactam. Hydrophobicity-assisted surface mediated model peptide formation highlighted that the microenvironment and pKaperturbation led to poor regioselectivity (α-aminevs.terminal amine) in Dpr and other non-proteinogenic analogues. The α-selectivity became even poorer in the presence of phosphate, making them ill-suited for peptide synthesis. Superior regioselectivity of the Lys aa-tRNA model substrate suggests that the extra methylene bridge helped nature to separate the microenvironments of the α-amine and ε-amine to synthesize the peptide backbone.
N-alpha-fluorenylmethoxycarbonyl-N',N''-diformyl allyl-L-arginine preparation method
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Paragraph 0014; 0019; 0023; 0027; 0031, (2019/10/22)
The invention discloses an N-alpha-fluorenylmethoxycarbonyl-N',N''-diformyl allyl-L-arginine preparation method and mainly solves technical problems of complexity, long period, high cost and the likein an original process. The technical scheme includes steps: step one, mixing L-arginine with acetone solution of a t-butyloxycarboryl donor to obtain N-alpha-t-butyloxycarboryl-L-arginine; step two,mixing N-alpha-t-butyloxycarboryl-L-arginine, a formic allyl donor and a catalyst in THF, and performing catalytic reaction under the action of organic alkali to obtain N-alpha-t-butyloxycarboryl-N',N''-diformyl allyl-L-arginine; step three, adding the N-alpha-t-butyloxycarboryl-N',N''-diformyl allyl-L-arginine into a t-butyloxycarboryl deprotection reagent to remove t-butyloxycarboryl to obtain N',N''-diformyl allyl-L-arginine monohydrochloride; step four, mixing the N',N''-diformyl allyl-L-arginine monohydrochloride with acetone solution of a fluorenylmethoxycarbonyl amino protection agent to obtain N-alpha-fluorenylmethoxycarbonyl-N',N''-diformyl allyl-L-arginine.
N,N,N-Tris(tert-butoxycarbonyl)-l-arginine: five isoforms whose obtainment depends on procedure and scrupulous NMR confirmation of their structures
Alfei, Silvana,Castellaro, Sara
, p. 1811 - 1832 (2017/12/04)
l-arginine is often covalently linked to vectors for gene or drug delivery as a means of increasing their transfection activity and reducing toxicity. This strategy relies on the protection of basic nitrogen atoms, for example, by employing the tert-butoxycarbonyl group. Our aim in the present work was to prepare the widely described αN,ωN,ω′N-tris(tert-butyloxycarbonyl)-l-arginine as a single isomer in high yield and with high levels of purity for use in the esterification of dendrimers with several peripheral hydroxyl groups. Following three reported protocols which assured this goal, we observed the unexpected formation of four additional isomers. Using the first procedure, αN,ωN,ω′N-tris(tert-butyloxycarbonyl)-l-arginine was never obtained. The second procedure delivered the desired compound as a mixture of geometric isomers (E/Z), while the third protocol led to a single isomer in high yield and purity, but with an unreported symmetrical structure. Since Boc protection is transient, this discovery would seem to be of little interest, but preliminary results from an ongoing investigation of the behavior of each of the isomers obtained in the esterification reactions of interest has shown that their reactivity depends on their structure. Although this research is ongoing, here we report a detailed description of these unexpected results, along with an NMR investigation focusing on the double-bond geometry and position which enabled confirmation of the structures.
A kind of amino acid- the amine decorates composition and its preparation method and application
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Paragraph 0069; 0070; 0073, (2017/04/05)
The invention belongs to the field of medicinal chemistry and in particular relates to amino acid-amine conjugate and a preparation method and application thereof. A general formula of the amino acid-amine conjugate is shown in the specification. According to the amino acid-amine conjugate, amino acid and amine are combined together, the water solubility, biological properties and drug targeting of amine compounds can be improved, and anti-cancer targeting can be realized.
Ophthalmic liposomes
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, (2008/06/13)
A liposome composition with enhanced retention on ocular surfaces, for use in ophthalmic drug delivery and dry eye treatment. The liposomes contain about 10-40 mole percent of an amine-derivatized lipid component in which a charged amine group is spaced from a lipid polar head region by a carbon-containing spacer arm at least 3 atoms in length. The liposomes preferably have a close packed lipid structure produced by inclusion of between 20-50 mole percent of cholesterol or an amine-derivatized cholesterol, and/or phospholipids with predominantly saturated acyl chain moieties. The liposomes may be suspended in an aqueous medium containing a high-viscosity polymer, formulated in paste form, or embedded in a polymer matrix, to enhance further the retention of liposomes on a corneal surface.
Synthesis of a proposed antigenic hexapeptide from Escherichia coli K88 protein fimbriae.
Meldal,Kindtler
, p. 235 - 241 (2007/10/02)
The hexapeptide Boc-Asp-Asp-Tyr-Arg-Gln-Lys-OMe is assembled by stepwise synthesis in solution with an overall yield of 44%. N alpha-boc-amino acids, protected with benzyl or benzyloxycarbonyl groups in the side-chains, are coupled as active estes of 1-hydroxybenzotriazole in mixtures of dichloromethane and N,N-dimethylformamide. N alpha-deprotection is accomplished with trifluoroacetic acid. Finally, hydrogenation with palladium on charcoal and ammonium formate produces the pure hexapeptide. A new one-pot synthesis of Boc-Arg(Z2) is described, and the use of this derivative in peptide coupling is studied. The synthetic peptide was coupled to BSA and used in direct immunication of rabbits.