- Modifying ICCA with trp-phe-phe to enhance in vivo activity and form nano-medicine
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Background: 1-(4-isopropylphenyl)-β-carboline-3-carboxylic acid (ICCA) was modified by Trp-Phe-Phe to form 1-(4-isopropylphenyl)-β-carboline-3-carbonyl-Trp-Phe-Phe (ICCA-WFF). Purpose: The object of preparing ICCA-WFF was to enhance the in vivo efficacy of ICCA, to explore the possible targeting action, and to visualize the nano-feature. Methods: The advantages of ICCA-WFF over ICCA were demonstrated by a series of in vivo assays, such as anti-tumor assay, anti-arterial thrombosis assay, anti-venous thrombosis assay, P-selectin expression assay, and GPIIb/IIIa expression assay. The nano-features of ICCA-WFF were visualized by TEM, SEM and AFM images. The thrombus targeting and tumor-targeting actions were evidenced by FT-MS spectrum analysis. Results: The minimal effective dose of ICCA-WFF slowing tumor growth and inhibiting thrombosis was 10-fold lower than that of ICCA. ICCA-WFF, but not ICCA, formed nano-particles capable of safe delivery in blood circulation. In vivo ICCA-WFF, but not ICCA, can target thrombus and tumor. In thrombus and tumor, ICCA-WFF released Trp-Phe-Phe and/or ICCA. Conclusion: Modifying ICCA with Trp-Phe-Phe successfully enhanced the anti-tumor activity, improved the anti-thrombotic action, formed nano-particles, targeted tumor tissue and thrombus, and provided an oligopeptide modification strategy for heterocyclic compounds.
- Chen, Haiyan,Peng, Shiqi,Wang, Yaonan,Wu, Jianhui,Zhang, Xiaoyi,Zhang, Yixin,Zhao, Ming
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p. 465 - 481
(2020/02/04)
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- Self-Assembly of Tetraphenylalanine Peptides
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Three different tetraphenylalanine (FFFF) based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies under a variety of conditions. The FFFF peptide assembles into nanotubes that show more structural imperfections at the surface than those formed by the diphenylalanine (FF) peptide under the same conditions. Periodic DFT calculations (M06L functional) were used to propose a model that consists of three FFFF molecules defining a ring through head-to-tail NH3+?-OOC interactions, which in turn stack to produce deformed channels with internal diameters between 12 and 16 ?. Depending on the experimental conditions used for the peptide incubation, N-fluorenylmethoxycarbonyl (Fmoc) protected FFFF self-assembles into a variety of polymorphs: ultra-thin nanoplates, fibrils, and star-like submicrometric aggregates. DFT calculations indicate that Fmoc-FFFF prefers a parallel rather than an antiparallel β-sheet assembly. Finally, coexisting multiple assemblies (up to three) were observed for Fmoc-FFFF-OBzl (OBzl = benzyl ester), which incorporates aromatic protecting groups at the two peptide terminals. This unusual and noticeable feature is attributed to the fact that the assemblies obtained by combining the Fmoc and OBzl groups contained in the peptide are isoenergetic. Variety show! Three different tetraphenylalanine-based peptides that differ at the N- and C-termini have been synthesized by using standard procedures to study their ability to form different nanoassemblies (e.g., nanotubes, see figure) under a variety of conditions.
- Mayans, Enric,Ballano, Gema,Casanovas, Jordi,Díaz, Angélica,Pérez-Madrigal, Maria M.,Estrany, Francesc,Puiggalí, Jordi,Cativiela, Carlos,Alemán, Carlos
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p. 16895 - 16905
(2015/11/16)
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- Electrochemical removal of the picolinoyl group under mild acidic conditions, application to the protection of amines in peptide synthesis
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The picolinoyl group can be used as a convenient protective group for amines in peptide chemistry. Deprotection is performed by electrochemical reduction under mild acidic conditions.
- Auzeil, Nicolas,Dutruc-Rosset, Gilles,Largeron, Martine
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p. 2283 - 2286
(2007/10/03)
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- ENZYMIC SYNTHESIS OF OLIGOPETIDE - VI. THE MECHANISTIC FEATURES OF PEPSIN-CATALYSED PEPTIDE SYNTHESIS
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The dipeptide Z-Phe-Phe-OBzl and tripeptide Z-Phe-Phe-Phe-OBzl were synthesized by pepsin catalysis from the incubation of Z-Phe and Phe-OBzl in the reaction solution.The yield ratio of two peptides in relation to reaction time was investigated by HPLC.Another example: The tripeptide Z-Phe-Leu-Phe-OBzl and tetrapeptide Z-Phe-Leu-Phe-Phe-OBzl were also synthesized concurrently from Z-Phe-Leu and Phe-OBzl by pepsin catalysis.These results may have important implication for the transpeptidation of pepsin.But, according to the report of Pellegrini and Luisi, the dipeptide, Z-Ph-Phe-OBzl, synthesized by pepsin catalysis was not contaminated with the tripeptide,Z-Phe-Phe-Phe-OBzl, and the yield was high.In order to investigate the discrepancies between our observation and those reported by Pellegrini and Luisi, a mechanism by which pepsin synthesizes the dipeptide, Z-Phe-Phe-OBzl, and tripeptide, Z-Phe-Phe-Phe-OBzl, is proposed and supporting data demonstrated by HPLC analysis.
- Tseng, Min-Jen,Wu, Shih-Hsiung,Wang, Kung-Tsung
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- The Steric Hindrance of the Stepwise Reaction of N-Carboxy α-Amino Acid Anhydride with the α-Amino Acid Ester
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The mechanisms of the reactions of 4-alkyloxazolidinediones (1) (N-carboxy α-amino acid anhydrides(NCAs)) with α-amino acid benzyl ester p-toluenesulfonates (2) were investigated in acetonitrile containing triethylamine at low and room temperatures.Two types of reactions were observed: (1) the polymerization of NCAs was initiated with a small amount of 2 to produce polypeptides (6), and (2) the dipeptide benzyl esters (4) were produced by the stepwise reaction of NCAs with the esters.Both the polymerization and the dipeptide formation (1+2) seemed to be initiated by the nucleophilic attack of the amino group of the ester on the C-5 carbon of NCAs.The polymerization proceeded when the side chains of the amino acid esters (R2) were more bulky than those of the NCAs (R1).On the contrary, dipeptide esters were produced when the side chains of the NCAs (R1) were more bulky than those of the esters (R2).
- Oya, Masanao,Takahashi, Tomoko
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p. 2705 - 2707
(2007/10/02)
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