- Chemoselective Peptide Cyclization and Bicyclization Directly on Unprotected Peptides
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Cyclic peptides are drawing wide attention as potential medium-sized modulators of biomolecular interactions with large binding surfaces. Simple but effective peptide cyclization methods are needed to construct cyclic peptide libraries by both peptide and nonpeptide chemists. Herein, we report a highly chemoselective and operation-simple method directly cyclizing unprotected peptides, in which ortho-phthalaldehyde (OPA) is found to react with the lysine/N-terminus and cysteine within one unprotected peptide sequence effectively to form the isoindole-bridged cyclic peptides. This reaction is carried out in the aqueous buffer and features tolerance of diverse functionalities, rapid and clean transformation, and operational simplicity. In addition, OPA peptide cyclization can also be combined with native chemical ligation-mediated cyclization to generate bicyclic peptides. Furthermore, the OPA peptide cyclization product can further react with the N-maleimide moiety in a one-pot manner to introduce additional functional motifs, like a fluorophore probe, biomolecules (e.g., glycan, peptide, or DNA). This OPA-cyclization method extends the toolbox for integrating postcyclization modification and bioconjugation into peptide cyclization with an all-in-one manner strategy.
- Zhang, Yue,Zhang, Qing,Wong, Clarence T. T.,Li, Xuechen
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- Synthesis of maleimide-functionalyzed HPMA-Copolymers and in vitro characterization of the aRAGE- and human immunoglobulin (huIgG)-polymer conjugates
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Herein the synthesis of antibody-polymer conjugates, with a quite narrow dispersity based on the polymer HPMA, are reported. These conjugates are synthesized by coupling antibodies to maleimide-functionalized poly(N-(2-hydroxypropyl)-methacrylamide) (poly-HPMA) copolymers derived through reversible addition-fragmentation chain transfer (RAFT) polymerization of pentafluorophenyl methacrylate via the intermediate step of an activated ester polymer. We develop a protocol that allows the attachment of two different model antibodies, monoclonal anti-RAGE (receptor for advanced glycation end-products) antibody, and polyclonal human immunoglobulin (huIgG). Modification of the antibody and conjugation is monitored by SDS-PAGE electrophoresis. Preserved affinity is demonstrated by Western Blott and cell-uptake analysis, for example, to cells of the immune system.
- Tappertzhofen, Kristof,Metz, Verena V.,Hubo, Mario,Barz, Matthias,Postina, Rolf,Jonuleit, Helmut,Zentel, Rudolf
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- N-(3-Triethoxysilylpropyl)-4-(N′-maleimidylmethyl)cyclohexanamide (TPMC): A heterobifunctional reagent for immobilization of oligonucleotides on glass surface
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A new heterobifunctional reagent, namely, N-(3-triethoxysilylpropyl)-4-(N′-maleimidylmethyl)cyclohexanamide (TPMC) was developed and its potentiality for fixing of thiol (-SH) modified oligonucleotides were tested. The covalent attachment of oligonucleoti
- Misra, Arvind
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- One-pot solvent free, green route to novel substituted spiro[oxindole-isoxazolidine] derivatives: novel candidates as antimicrobial agents
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The environmentally benign catalyst and solvent-free synthesis of ketonitrones may not always be accomplished by simple condensation reactions. The occasional reports of green synthetic routes toward these compounds have been reported. The key features of
- KAUR, MANPREET,BHATIA, SUMEET KAUR,SINGH, BALDEV
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p. 1299 - 1303
(2021/06/09)
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- Synthesis, characterization, and targeted chemotherapy of SCT200-linker-monomethyl auristatin E conjugates
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Antibody-drug conjugates (ADCs) are currently among the most successful and important strategies for treating patients with solid tumors. ADCs are composed of a monoclonal antibody and warhead, which are conjugated via a linker. Currently, monomethyl auristatin E (MMAE) is the most widely applied warhead in the development of ADCs. However, MMAE-based ADCs are generally constructed using the MC-VC-PABC linker, and this design has limited structural diversity and some disadvantages. Accordingly, in this study, we generated three types of novel linker-MMAE (with alterations in the spacer, catabolizing area, and self-immolative compared with MC-VC-PABC-MMAE) in ADCs, termed SCT200-linker-MMAE conjugates, and then evaluated the linker-drug plasma stability and the rate of drug release by cathepsin B. The binding ability, internalization rates, and efficacy of all SCT200-linker-MMAE ADCs were systematically studied, and the expression of apoptosis-associated proteins and the therapeutic efficacies of SCT200-M-2, -C-2, and -C-4 were evaluated. The results showed that the activities of some of these ADCs were increased for epidermal growth factor receptor-positive tumors. Moreover, the novel linkers designed in this study can be linked with other antibodies to treat other types of cancer. Overall, these findings provide important insights into the application of SCT200-based linkers in ADCs.
- Hu, Xinyue,Jiang, Hailun,Bai, Weiqi,Liu, Xiujun,Miao, Qingfang,Wang, Linlin,Jin, Jie,Cui, Along,Liu, Rui,Li, Zhuorong
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supporting information
(2021/03/08)
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- CYCLIC COMPOUNDS AND METHODS OF MAKING AND USING
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Disclosed are compounds and methods for highly effective chemoselective peptide cyclization and bicyclization directly on unprotected peptides and other compounds as well as the compounds produced by the methods, which have a novel structural motif. The fast reaction rate and operational simplicity render this method to be highly effective to synthesize cyclic structures, i.e. cyclic peptides. The cyclic compounds allow for various functionalities useful in chemical biology study and drug discovery.
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Page/Page column 110
(2020/10/19)
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- PHARMACEUTICAL COMPOSITIONS COMPRISING MACROLIDE DIASTEREOMERS, METHODS OF THEIR SYNTHESIS AND THERAPEUTIC USES
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The disclosure relates to compositions comprising diastereomer of a macrolide exhibiting improved therapeutic profile in the context of inhibiting cell proliferation compared to the corresponding compositions comprising mixture of diastereomers. The discl
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Paragraph 00103
(2015/03/16)
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- ANTICANCER CONJUGATE
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An anticancer conjugate, which comprises a fusion protein comprising domain (a), which is the functional fragment of a sequence of soluble human TRAIL (hTRAIL) protein beginning with an amino acid at a position not lower than hTRAIL95 or a sequence having at least 70% identity with said functional fragment, domain (b) which is the sequence of an effector peptide having proapoptotic, antiangiogenic, antiproliferative or pore forming activity, and conjugation domain (d) for attachment of a chemical compound selected from the group consisting of the sequences Cys Ala Ala Ala Cys Ala Ala Cys and Cys Ala Ala Cys Ala Ala Ala Cys, and a molecule of a chemical compound Z having antiblastic activity, which is attached to said conjugation domain (d) of said fusion protein directly or via a conjugation linker L.
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- Azide-alkyne cycloaddition for universal post-synthetic modifications of nucleic acids and effective synthesis of bioactive nucleic acid conjugates
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The regioselective post-synthetic modifications of nucleic acids are essential to studies of these molecules for science and applications. Here we report a facile universal approach by harnessing versatile phosphoramidation reactions to regioselectively incorporate alkynyl/azido groups into post-synthetic nucleic acids primed with phosphate at the 5′ termini. With and without the presence of copper, the modified nucleic acids were subjected to azide-alkyne cycloaddition to afford various nucleic acid conjugates including a peptide-oligonucleotide conjugate (POC) with high yield. The POC was inoculated with human A549 cells and demonstrated excellent cell-penetrating ability despite cell deformation caused by a small amount of residual copper chelated to the POC. The combination of phosphoramidation and azide-alkyne cycloaddition reactions thus provides a universal regioselective strategy to post-synthetically modify nucleic acids. This study also explicated the toxicity of residual copper in synthesized bioconjugates destined for biological systems. This journal is the Partner Organisations 2014.
- Su, Yu-Chih,Lo, Yu-Lun,Hwang, Chi-Ching,Wang, Li-Fang,Wu, Min Hui,Wang, Eng-Chi,Wang, Yun-Ming,Wang, Tzu-Pin
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p. 6624 - 6633
(2014/08/18)
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- Comparison of hydrazone heterobifunctional cross-linking agents for reversible conjugation of thiol-containing chemistry
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Reversible covalent conjugation chemistries that allow site- and condition-specific coupling and uncoupling reactions are attractive components in nanotechnologies, bioconjugation methods, imaging, and drug delivery systems. Here, we compare three heterob
- Christie, R. James,Anderson, Diana J.,Grainger, David W.
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experimental part
p. 1779 - 1787
(2011/11/06)
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