2566-29-2Relevant articles and documents
Efficient, practical synthesis of symmetrically α,α-disubstituted α-amino acids
Ellis, Trevor K.,Martin, Collin H.,Ueki, Hisanori,Soloshonok, Vadim A.
, p. 1063 - 1066 (2003)
Ni(II)-complex derived from glycine Schiff base with 2-[N-(α-picolyl)amino]benzophenone (PABP) was found to be an ideal equivalent of nucleophilic glycine in the reactions with various alkyl halides affording an efficient, generalized and practically usef
Tracking a new cell-penetrating (W/R) nonapeptide, through an enzyme-stable mass spectrometry reporter tag
Delaroche, Diane,Aussedat, Baptiste,Aubry, Soline,Chassaing, Gerard,Burlina, Fabienne,Clodic, Gilles,Bolbach, Gerard,Lavielle, Solange,Sagan, Sandrine
, p. 1932 - 1938 (2007/10/03)
We have designed a mass stable reporter (msr) tag with m/z over 500, trifluoroacetyl(α,α-diemyl)Gly-Lys(Nebiotin)-(D)Lys-Cys, for the quantification of the uptake and study of the degradation processes of cell-penetrating peptides (CPP), by matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. This tag was found stable in cell lysis conditions. Using a quantitative MALDI-TOF mass spectrometry analysis based method, an accurate tracking of a new CPP and of its degradation products could be done. (1) The new msr(W/ R) nonapeptide (H-RRWWRRWRR-NH 2) enters chinese hamster ovary (CHO) K1 cells with a kinetic reaching a steady state after 30-60 min of incubation. This plateau was stable for 4 h and decreased slowly afterward. (2) The peptide msr(W/R) nonapeptide was not cytotoxic over 48 h incubation with CHO cells. (3) After 1 h incubation, the msr(W/R) nonapeptide accumulated with a 3-fold higher concentration than the extracellularly added concentration (7.5 μM). (4) The intracellular quantification was accurate with less than 3% of the quantified peptide being potentially membrane-bound. (5) There was no leakage of the full-length CPP outside the cells. And, finally, (6) analysis of the degradation process of this new CPP suggests that the peptide did not traffick to lysosomes.
Synthesis and biological activity of nociceptin/orphanin FQ analogues substituted in position 7 or 11 with Cα,α-dialkylated amino acids
Arduin, Marika,Spagnolo, Barbara,Calo, Girolamo,Guerrini, Remo,Carra, Giacomo,Fischetti, Carmela,Trapella, Claudio,Marzola, Erika,McDonald, John,Lambert, David G.,Regoli, Domenico,Salvadori, Severo
, p. 4434 - 4443 (2008/03/13)
Previous structure-activity and NMR studies on nociceptin/orphanin FQ (N/OFQ) demonstrated that Aib substitution of Ala7 and/or Ala11 increases the peptide potency through an alpha helix structure induction mechanism. On these bases we synthesised and evaluated pharmacologically in the mouse vas deferens assay a series of N/OFQ-NH2 analogues substituted in position 7 and 11 with Cα,α-disubstituted cyclic, linear and branched amino acids. None of the 20 novel N/OFQ analogues produced better results than [Aib7]N/OFQ-NH2. Thus, this substitution was combined with other chemical modifications known to modulate peptide potency and/or efficacy generating compound 21 [Nphe1Aib7Arg14Lys15]N/OFQ-NH2 (coded as UFP-111), compound 22 [(pF)Phe4Aib7Arg14Lys15]N/OFQ-NH2 (UFP-112) and compound 23 [Phe1Ψ(CH2-NH)Gly2(pF)Phe4Aib7Arg14Lys15]N/OFQ-NH2 (UFP-113). These novel peptides behaved as highly potent NOP receptor ligands showing full (UFP-112) and partial (UFP-113) agonist and pure antagonist (UFP-111) activities in a series of in vitro functional assays performed on pharmacological preparations expressing native as well as recombinant NOP receptors.
Synthesis of α-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Nickel(II) Complexes of Glycine-Derived Schiff Bases
Belokon, Yuri N.,Bespalova, Natalia B.,Churkina, Tatiana D.,Cisarova, Ivana,Ezernitskaya, Marina G.,Harutyunyan, Syuzanna R.,Hrdina, Radim,Kagan, Henri B.,Kocovsky, Pavel,Kochetkov, Konstantin A.,Larionov, Oleg V.,Lyssenko, Konstantin A.,North, Michael,Polasek, Miroslav,Peregudov, Alexander S.,Prisyazhnyuk, Vladimir V.,Vyskocil, Stepan
, p. 12860 - 12871 (2007/10/03)
Achiral, diamagnetic Ni(II) complexes 1 and 3 have been synthesized from Ni(II) salts and the Schiff bases, generated from glycine and PBP (7) and PBA (11), respectively, in MeONa/MeOH solutions. The requisite carbonyl-derivatizing agents pyridine-2-carboxylic acid(2-benzoyl-phenyl)-amide 7 (PBP) and pyridine-2-carboxylic acid(2-formyl-phenyl)-amide 11 (PBA) were readily prepared from picolinic acid and o-aminobenzophenone or picolinic acid and methyl o-anthranilate, respectively. The structure of 1 was established by X-ray crystallography. Complexes 1 and 3 were found to undergo C-alkylation with alkyl halides under PTC conditions in the presence of β-naphthol or benzyltriethylammonium bromide as catalysts to give mono- and bis-alkylated products, respectively. Decomposition of the complexes with aqueous HCI under mild conditions gave the required amino acids, and PBP and PBA were recovered. Alkylation of 1 with highly reactive alkyl halides, carried out under the PTC conditions in the presence of 10% mol of (S)- or (R)-2-hydroxy-2′ -amino-1,1′-binaphthyl 31a (NOBIN) and/or its N-acyl derivatives and by (S)- or (R)-2-hydroxy-8′-amino-1,1′-binaphthyl 32a (iso-NOBIN) and its N-acyl derivatives, respectively, gave rise to α-amino acids with high enantioselectivities (90-98.5% ee) in good-to-excellent chemical yields at room temperature within several minutes. An unusually large positive nonlinear effect was observed in these reactions. The Michael addition of acrylic derivatives 37 to 1 was conducted under similar conditions with up to 96% ee. The 1H NMR and IR spectra of a mixture of the sodium salt of NOBIN and 1 indicated formation of a complex between the two components. Implications of the association and self-association of NOBIN for the observed sense of asymmetric induction and nonlinear effects are discussed.
Efficient synthesis of serically constrained smmetrically alpha,alpha-disubstituted alpha-amino acids under operationally convenient conditions.
Ellis, Trevor K,Martin, Collin H,Tsai, Gary M,Ueki, Hisanori,Soloshonok, Vadim A
, p. 6208 - 6214 (2007/10/03)
Homologation of the nucleophilic glycine equivalent Ni-Gly-PABP [Ni(II) complex of glycine Schiff base with 2-[N-(alpha-picolyl)amino]benzophenone (PABP)] 2 via alkyl halide alkylations and Michael addition reactions was systematically studied as a general method for preparing symmetrically alpha,alpha-disubstituted alpha-amino acids (sym-alpha,alpha-AA). The dialkylation reactions are conducted under operationally convenient conditions without recourse to inert atmosphere, dried solvents, and low temperatures, thus enjoying key advantages of the experimental simplicity and attractive cost structure. The method has been shown to be particularly successful for the dialkylation of complex 2 with activated and nonactivated alkyl halides, including propargyl derivatives, affording a generalized and practical access to the corresponding sym-alpha,alpha-AA. This study has also shown some limitation of the method, as it cannot be extended to alpha- or beta-branched alkyl halides or Michael acceptors to be used for the dialkylation of glycine equivalent 2. High chemical yields of the dialkylated products, combined with the simplicity of the experimental procedure, render this method worth immediate use for multigram scale preparation of the sym-alpha,alpha-AA.
