- Peptide/peptoid hybrid oligomers: The influence of hydrophobicity and relative side-chain length on antibacterial activity and cell selectivity
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Previous optimisation studies of peptide/peptoid hybrids typically comprise comparison of structurally related analogues displaying different oligomer length and diverse side chains. The present work concerns a systematically constructed series of 16 closely related 12-mer oligomers with an alternating cationic/hydrophobic design, representing a wide range of hydrophobicity and differences in relative side-chain lengths. The aim was to explore and rationalise the structure-activity relationships within a subclass of oligomers displaying variation of three structural features: (i) cationic side-chain length, (ii) hydrophobic side-chain length, and (iii) type of residue that is of a flexible peptoid nature. Increased side-chain length of cationic residues led to reduced hydrophobicity till the side chains became more extended than the aromatic/hydrophobic side chains, at which point hydrophobicity increased slightly. Evaluation of antibacterial activity revealed that analogues with lowest hydrophobicity exhibited reduced activity against E. coli, while oligomers with the shortest cationic side chains were most potent against P. aeruginosa. Thus, membrane-disruptive interaction with P. aeruginosa appears to be promoted by a hydrophobic surface of the oligomers (comprised of the aromatic groups shielding the cationic side chains). Peptidomimetics with short cationic side chains exhibit increased hemolytic properties as well as give rise to decreased HepG2 (hepatoblastoma G2 cell line) cell viability. An optimal hydrophobicity window could be defined by a threshold of minimal hydrophobicity conferring activity toward E. coli and a threshold for maximal hydrophobicity, beyond which cell selectivity was lost.
- Frederiksen, Nicki,Hansen, Paul R.,Bj?rkling, Fredrik,Franzyk, Henrik
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- Leccinine A, an endoplasmic reticulum stress-suppressive compound from the edible mushroom Leccinum extremiorientale
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Leccinine A (1) along with a known compound (2), were isolated from the edible mushroom Leccinum extremiorientale. The structure of 1 was determined by the interpretation of spectral data. Leccinine A showed protective activity against endoplasmic reticulum stress-dependent cell death. Seven analogues (3-9) of 1 were synthesized in order to evaluate the structure-activity relationship, and the result indicated that the formamide group of 1 was indispensable for the activity.
- Choi, Jae-Hoon,Ozawa, Nobuhiko,Yamakawa, Yasuhiro,Nagai, Kaoru,Hirai, Hirofumi,Kawagishi, Hirokazu
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experimental part
p. 6649 - 6653
(2011/09/30)
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- Peptoids bearing tertiary amino residues in the n-alkyl side chains: synthesis of a potent inhibitor of Semaphorin 3A
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A study on the preparation of N-alkylglycines (peptoids) that contain tertiary amino residues on the N-alkyl side chains is reported. The appropriate combination of the submonomer strategy with N-alkylglycine monomer couplings depending upon the structure of the N-alkyl side chain that must be incorporated into the peptoid is determinant for the efficiency of the synthetic pathway. The application of this strategy to the preparation of SICHI, an N-alkyglycine trimer containing tertiary amino residues in the three N-alkyl branches, and that has been identified as a potent Semaphorin 3A inhibitor, is presented.
- Messeguer, Joaquim,Masip, Isabel,Montolio, Marisol,del Rio, Jose Antonio,Soriano, Eduardo,Messeguer, Angel
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experimental part
p. 2444 - 2454
(2010/06/12)
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- Soluble Polymer-Supported Synthesis of α-Amino Acid Derivatives
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A practical and efficient synthesis of N-substituted α-amino acid derivatives on soluble polymer support is described.
- Hu, Chunling,Chen, Zuxing,Yang, Guichun
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p. 219 - 224
(2007/10/03)
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- Design of selective peptidomimetic agonists for the human orphan receptor BRS-3
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New tool substances may help to unravel the physiological role of the human orphan receptor BRS-3 and its possible use as a drug target for the treatment of obesity and cancer. In continuation of our work on BRS-3, the solid- and solution-phase synthesis of a library of low molecular weight peptidomimetic agonists based on the recently developed short peptide agonist 4 is described. Functional potencies of the compounds were determined measuring calcium mobilization in a fluorometric imaging plate reader (FLIPR) assay. Focusing on the N-terminus, the D-Phe-Gln moiety of 4 was modified in a combinatorial SAR-oriented medicinal chemistry approach. With the incorporation of N-arylated glycine and alanine building blocks azaglycine, piperazine, or piperidine and the synthesis of semicarbazides and semicarbazones, a number of highly potent and selective compounds with a reduced number of peptide bonds were obtained, which also should have enhanced metabolic stability.
- Weber, Dirk,Berger, Claudia,Eickelmann, Peter,Antel, Jochen,Kessler, Horst
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p. 1918 - 1930
(2007/10/03)
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- Dihydropyrancarboxamides related to zanamivir: A new series of inhibitors of influenza virus sialidases. 1. Discovery, synthesis, biological activity, and structure-activity relationships of 4-guanidino- and 4-amino-4h-pyran-6-carboxamides
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4-Amino- and 4-guanidino-4ff-pyran-6-carboxamides 4 and 5 related to zanamivir (GG167) are a new class of inhibitors of influenza virus sialidases. Structure-activity studies reveal that, in general, secondary amides are weak inhibitors of both influenza
- Smith, Paul W.,Sollis, Steven L.,Howes, Peter D.,Cherry, Peter C.,Starkey, Lan D.,Cobley, Kevin N.,Weston, Helen,Scicinski, Jan,Merritt, Andrew,Whittington, Andrew,Wyatt, Paul,Taylor, Neil,Green, Darren,Bethell, Richard,Madar, Safia,Fenton, Robert J.,Morley, Peter J.,Pateman, Tony,Beresford, Alan
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p. 787 - 797
(2007/10/03)
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