- Fmoc-OPhth, the reagent of Fmoc protection
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Fmoc-OSu has been widely used for Fmoc protection of amino groups, especially amino acids, in solid phase peptide synthesis. However, it has been recognized that Fmoc-βAla-OH is formed as a by-product via the Lossen rearrangement during the reaction. Since we reconfirmed the formation of Fmoc-βAla-OH during the preparation of Fmoc-AA-OH by Fmoc-OSu, Fmoc-OPhth was designed and synthesized as a new Fmoc reagent to avoid the formation of Fmoc-βAla-OH. Furthermore, Fmoc protection by Fmoc-OPhth and Fmoc-SPPS were evaluated. The various Fmoc-amino acids prepared by Fmoc-OPhth were carried out in good yields and these are applicable in Fmoc-SPPS.
- Yoshino, Ryo,Tokairin, Yoshinori,Kikuchi, Mari,Konno, Hiroyuki
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- Benzotriazole reagents for the syntheses of Fmoc-, Boc-, and Alloc-protected amino acids
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Stable Fmoc-, Boc-, and Alloc-benzotriazoles react with various amino acids including unprotected serine and glutamic acid, in the presence of triethylamine at 20° as reagents to introduce -amino protecting groups to afford Fmoc-, Boc-, and Alloc-protected amino acids (77-94%) free of dipeptide and tripeptide impurities. Fmoc-, and Alloc-Gly-Gly-OH dipeptides were prepared in 90% yields by N-acylation of glycylglycine with Fmoc- and Alloc-benzotriazoles in the presence of triethylamine. Synthesized N-protected amino acids were greater than 99% pure, analyzed by HPLC. Georg Thieme Verlag Stuttgart - New York.
- Ibrahim, Tarek S.,Tala, Srinivasa R.,El-Feky, Said A.,Abdel-Samii, Zakaria K.,Katritzky, Alan R.
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- Liquid-chromatography quantitative analysis of 20 amino acids after derivatization with FMOC-CI and its application to different origin Radix isatidis
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We developed a simple, rapid and reliable method for determination of 20 common amino acids based on derivatization with 9-fluorenylmethyl chloroformate (FMOC-CI) and RP-LC/UV, this method was first introduced into quantitative analysis of amino acids. The amino groups of amino acids were trapped with FMOC-CI to form amino acid-FMOC-Cl adducts which can be suitable for LC-UV. Chromatographic separation was performed on a C18 column with a mobile phase gradient consisting of acetonitrile and sodium acetate solution. This method was shown to be sensitive for 20 common amino acids. In the intra-day precisions assay, the range of RSDs was 3.21-7.67% with accuracies of 92.34-102.51%; for the inter-day precisions assay, the range of RSDs was 5.82-9.19% with accuracies of 90.25-100.63%. The results also indicated that solutions of amino acids-FMOC-Cl can be kept at room temperature for at least 24 h without showing significant losses in the quantified values. The validated method was successfully applied to the determination of major four kinds of amino acids in R. isatidis samples (Arg, Pro, Met and Val). The total content of amino acids in different origin R. isatidis was 13.32-19.16 mg/g. The differences between R. isatidis samples were large using HCA.
- Zhou, Wei,Zhang, Xiao-Yan,Duan, Geng-Li
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- Molecular Scaffolds as Double-Targeting Agents For the Diagnosis and Treatment of Neuroblastoma
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The selective delivery of therapeutic and imaging agents to tumoral cells has been postulated as one of the most important challenges in the nanomedicine field. Meta-iodobenzilguanidine (MIBG) is widely used for the diagnosis of neuroblastoma (NB) due to its strong affinity for the norepinephrine transporter (NET), usually overexpressed on the membrane of malignant cells. Herein, a family of novel Y-shaped scaffolds has been synthesized, which have structural analogues of MIBG covalently attached at each end of the Y-structure. The cellular uptake capacity of these double-targeting ligands has been evaluated in vitro and in vivo, yielding one specific Y-shaped structure that is able to be engulfed by the malignant cells, and accumulates in the tumoral tissue, at significantly higher levels than the structure containing only one single targeting agent. This Y-shaped ligand can provide a powerful tool for the current treatment and diagnosis of this disease.
- Villaverde, Gonzalo,Alfranca, Arantzazu,Gonzalez-Murillo, áfrica,Melen, Gustavo J.,Castillo, Rafael R.,Ramírez, Manuel,Baeza, Alejandro,Vallet-Regí, María
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- Conjugate (MTC-220) of muramyl dipeptide analogue and paclitaxel prevents both tumor growth and metastasis in mice
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1 (MTC-220), a conjugate of paclitaxel and a muramyl dipeptide analogue, has been synthesized as a novel agent of dual antitumor growth and metastasis activities. In vitro and in vivo tests show that 1 retains its ability to inhibit tumor growth. It is su
- Ma, Yao,Zhao, Nan,Liu, Gang
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- New TFA-free cleavage and final deprotection in Fmoc solid-phase peptide synthesis: Dilute HCl in fluoro alcohol
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A novel method for cleaving from resin and removing acid-labile protecting groups for the Fmoc solid-phase peptide synthesis is described. 0.1 N HCl in hexafluoroisopropanol or trifluoroethanol cleanly and rapidly removes the tert-butyl ester and ether, Boc, trityl, and Pbf groups and cleaves the common resin linkers: Wang, HMPA, Rink amide, and PAL. Addition of just 5-10% of a hydrogen-bonding solvent considerably retards or even fully inhibits the reaction. However, a non-hydrogen-bonding solvent is tolerated.
- Palladino, Pasquale,Stetsenko, Dmitry A.
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- Multicomponent hydrogels from enantiomeric amino acid derivatives: Helical nanofibers, handedness and self-sorting
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In this study, chiral helical nanofibers have been obtained from suitable, co-assembling, two oppositely charged amino acid based two component hydrogels. An equimolar mixture of an N-terminally protected amino acid Fmoc-(l/d)Glu (Fmoc: N-fluorenyl-9-methoxycarbonyl, Glu: glutamic acid) and (l/d)Lys (Lys: lysine) can co-assemble to form hydrogels. These hydrogels have been characterised using circular dichroism (CD), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray powder diffraction, fluorescence spectroscopic and rheological studies. CD and AFM studies have been extensively used to examine the chiral/achiral nature of fibers obtained from different hydrogel systems. The equimolar mixture of two l-isomers, {Fmoc-(l)Glu + (l)Lys} in the assembled state, leads to the exclusive formation of left-handed helical nanofibers, whereas an equimolar mixture of two d-isomers, {Fmoc-(d)Glu + (d)Lys}, gives rise to right-handed helical nanofibers. The CD study of the gel obtained from the {Fmoc-(l)Glu + (l)Lys} system is exactly the mirror image of the CD signal obtained from the gel of the {Fmoc-(d)Glu + (d)Lys} system. These results suggest that the molecular chirality is being translated into the supramolecular helicity and the handedness of these fibers depends on the corresponding molecular chirality in the mixture of the two component system. Reversing the handedness of helical fibers is possible by using enantiomeric building blocks. Co-assembly of racemic and equimolar mixtures of all four components, i.e., [{Fmoc-(l)Glu + (l)Lys} + {Fmoc-(d)Glu + (d)Lys}] can also form hydrogels. Interestingly, in this racemic mixture self-sorting has been observed with the presence of almost equal amount of left- and right-handed helical nanofibers. The equimolar mixture of Fmoc-(l)Glu and l-ornithine/l-arginine also produces hydrogel with left-handed helical fibers. Moreover, the straight fiber has been observed from the two component hydrogel {Fmoc-(l)Glu + (l)Lys} system in the presence of Ca2+/Mg2+ ions. This indicates the straight nanofibers are obtained under suitable conditions and acid-base interaction is responsible for making the helical fibers at the nanoscale.
- Adhikari, Bimalendu,Nanda, Jayanta,Banerjee, Arindam
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- Easy saponification by metal silanolates: Application in SPPS and in (S)-5-hydroxynorvaline preparation
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Alkali metal trimethylsilanolates, TMSO-, M+, has been used for efficient conversion of methyl esters into their corresponding anhydrous acid salts under mild non-aqueous conditions. This strategy has been applied to SPPS for the preparation of neurotoxin cyclic analogues and in (S)-5-hydroxynorvaline synthesis.
- Minta, Ewelina,Boutonnet, Cédric,Boutard, Nicolas,Martinez, Jean,Rolland, Valérie
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- SUPRAMOLECULAR GEL SUPPORTED ON OPEN-CELL POLYMER FOAM
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The present invention relates to a polymer foam, said polymer foam comprising pores forming an open-cell polymer foam, said polymer foam comprising a supramolecular gel inside pores, and said polymer foam comprising at least one enzyme. The present invention relates to a supramolecular gel; its preparation and its applications, notably in chemical synthesis and kinetic resolution, in particular of organic compounds. The present invention also relates to flow chemistry.
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Page/Page column 16-17
(2021/03/19)
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- Preparation method of N-fluorenylmethoxycarbonyl-gamma-(S-triphenylmethyl-cysteamine)-L-glutamic acid
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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.
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Paragraph 0026
(2020/10/05)
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- Supported Catalytically Active Supramolecular Hydrogels for Continuous Flow Chemistry
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Inspired by biology, one current goal in supramolecular chemistry is to control the emergence of new functionalities arising from the self-assembly of molecules. In particular, some peptides can self-assemble and generate exceptionally catalytically active fibrous networks able to underpin hydrogels. Unfortunately, the mechanical fragility of these materials is incompatible with process developments, relaying this exciting field to academic curiosity. Here, we show that this drawback can be circumvented by enzyme-assisted self-assembly of peptides initiated at the walls of a supporting porous material. We applied this strategy to grow an esterase-like catalytically active supramolecular hydrogel (CASH) in an open-cell polymer foam, filling the whole interior space. Our supported CASH material is highly efficient towards inactivated esters and enables the kinetic resolution of racemates. This hybrid material is robust enough to be used in continuous flow reactors, and is reusable and stable over months.
- Rodon Fores, Jennifer,Criado-Gonzalez, Miryam,Chaumont, Alain,Carvalho, Alain,Blanck, Christian,Schmutz, Marc,Serra, Christophe A.,Boulmedais,Schaaf, Pierre,Jierry, Lo?c
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supporting information
p. 18817 - 18822
(2019/11/16)
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- LIGANDS FOR ENHANCED IMAGING AND DRUG DELIVERY TO NEUROBLASTOMA CELLS
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The present invention concerns aminobenzylguanidine derivative ligands specifically targeting neuroblastoma cells with an improved cellular uptake. The improved cellular uptake provides for the therapeutic and diagnostic use of the ligands in neuroblastoma-related diseases.
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(2019/10/23)
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- CHEMICAL SYNTHESIS AND ANTI-TUMOR AND ANTI-METASTATIC EFFECTS OF DUAL FUNCTIONAL CONJUGATE
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The present invention discloses chemical synthesis, anti-tumor and anti-metastatic effects of a dual functional conjugate as showed by formula I. In detail, paclitaxel or docetaxol is linked with muramyl dipeptide derivative to form a conjugate, thus dual anti-tumor and anti-metastatic effects are achieved by combination of chemotherapy and immunotherapy. The present invention also discloses that paclitaxel or docetaxol and muramyl dipeptide derivative conjugate is synthesized by combination of solid-phase and solution-phase synthesis, and said conjugate can be used in manufacture of anti-tumor medicaments as proved by reliable bioassays.
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Paragraph 0071; 0100-0101
(2017/10/24)
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- Chemical synthesis and anti-tumor and anti-metastatic effects of dual functional conjugate
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The present invention discloses chemical synthesis, anti-tumor and anti-metastatic effects of a dual functional conjugate as shown by formula I. Specifically, paclitaxel or docetaxol is linked with muramyl dipeptide derivative to form a conjugate, thus dual anti-tumor and anti-metastatic effects are achieved by combination of chemotherapy and immunotherapy. The present invention also discloses that paclitaxel or docetaxol and muramyl dipeptide derivative conjugate is synthesized by combination of solid-phase and solution-phase synthesis, and said conjugate can be used in manufacture of anti-tumor medicaments as proved by reliable bioassays.
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(2015/07/27)
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- CHEMICAL SYNTHESIS AND ANTI-TUMOR AND ANTI-METASTATIC EFFECTS OF DUAL FUNCTIONAL CONJUGATE
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The present invention discloses chemical synthesis, anti-tumor and anti-metastatic effects of a dual functional conjugate as shown by formula I. Specifically, paclitaxel or docetaxol is linked with muramyl dipeptide derivative to form a conjugate, thus dual anti-tumor and anti-metastatic effects are achieved by combination of chemotherapy and immunotherapy. The present invention also discloses that paclitaxel or docetaxol and muramyl dipeptide derivative conjugate is synthesized by combination of solid-phase and solution-phase synthesis, and said conjugate can be used in manufacture of anti-tumor medicaments as proved by reliable bioassays.
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(2013/06/26)
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- Amphiphilic cyclodextrin derivatives, method for preparation thereof and uses thereof
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The invention relates to cyclodextrin derivatives of formula (I): in which: R1═—NH-E-AA-(L1)p(L2)q where E=a linear or branched Cl-Cl5 hydrocarbon-based group with, optionally, one or more hetero atoms; AA=the residue of an amino acid; L1 and L2=a C6-C24 hydrocarbon-based group with, optionally, one or more hetero atoms; p and q=0 or 1, at least one being ≠0; R2═H, —CH3, isopropyl, hydroxypropyl, sulphobutyl ether; R3═H or R2, except when R2=hydroxypropyl; all the R4═—OH or R2, except when R2=hydroxypropyl, or at least one of the R4═R1; n=5, 6 or 7. The invention also relates to a process for preparing them, and to inclusion complexes and organized surfactant systems comprising them.
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(2010/11/27)
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- Substrate recognition mechanism of carboxypeptidase Y.
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To clarify the substrate-recognition mechanism of carboxypeptidase Y, Fmoc-(Glu)n Ala-OH (n = 1 to 6), Fmoc-(Glu)n Ala-NH2 (1 to 5), and Fmoc-Lys(Glu)3Ala-NH2 were synthesized, and kinetic parameters for these substrates were measured. Km for Fmoc-peptides significantly decreased as peptide length increased from n = 1 to n = 5 with only slight changes in kcat. Km for Fmoc-(Glu)(5,6)Ala-OH were almost the same as one for protein substrates described previously (Nakase et al., Bull. Chem. Soc. Jpn., 73, 2587-2590). These results show that the enzyme has six subsites (S1' and S1-S5). Each subsite affinity calculated from the Km revealed subsite properties, and from the differences of subsite affinity between pH 6.5 and 5.0, the residues in each subsite were predicted. For Fmoc-peptide amide substrates, the priorities of amidase and carboxamide peptidase activities were dependent on the substrate. It is likely that the interactions between side chains of peptide and subsites compensate for the lack of P1'-S1' interaction, so the amidase activity prevailed for Fmoc-(Glu)(3,5)Ala-NH2. These results suggest that these subsites contribute extensively to substrate recognition rather than a hydrogen bond network.
- Nakase,Murata,Ueno,Hayashi
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p. 2465 - 2471
(2007/10/03)
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- Improved efficiency and selectivity in peptide synthesis: Use of triethylsilane as a carbocation scavenger in deprotection of t-butyl esters and t-butoxycarbonyl-protected sites
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The use of triethylsilane as a carbocation scavenger in the presence of trifluoroacetic acid in dichloromethane leads to increased yields, decreased reaction times, simple work-up and improved selectivity for the deprotection of t-butyl ester and t-butoxycarbonyl sites in protected amino-acids and peptides in the presence of other acid-sensitive protecting groups such as the benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, O- and S-benzyl and t-butylthio groups.
- Mehta, Anita,Jaouhari, Rabih,Benson, Timothy J.,Douglas, Kenneth T.
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p. 5441 - 5444
(2007/10/02)
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