1142-20-7Relevant articles and documents
The peculiar behavior of Picha in the formation of metallacrown complexes with Cu(ii), Ni(ii) and Zn(ii) in aqueous solution
Marchi, Luciano,Marchetti, Nicola,Atzeri, Corrado,Borghesani, Valentina,Remelli, Maurizio,Tegoni, Matteo
, p. 3237 - 3250 (2015)
The thermodynamic stability of the metallacrown complexes formed by picolinehydroxamic acid (Picha) with Cu(ii), Ni(ii) and Zn(ii) in aqueous solution has been determined by potentiometry, and the speciation models were validated by ESI-MS and UV-visible spectrophotometry. Cu(ii) and Zn(ii) form 12-MC-4 species as the unique metallacrowns present in the solution. While for Cu(ii) the 12-MC-4 is slightly less stable than that obtained with alaninehydroxamic acid (Alaha), the opposite was found for Zn(ii). Moreover, with Cu(ii) unprecedented 15-MC-5 and 18-MC-6 species were identified under ESI-MS conditions. Picha with Ni(ii) forms, in contrast, a 15-MC-5 complex as a unique metallacrown species. Structural studies of the framework of the 12-MC-4 complexes by ab initio methods were also carried out. The results of our investigations allowed us to rationalize not only the different behaviour of Picha in the formation of metallacrowns with the three metal ions, but also the reasons which underpin the strategies for stabilization of these species reported in the literature using ancillary ligands such as pyridine. This journal is
Interactions between Terminally Substituted Amino Acids in an Aqueous and a Non-Aqueous Environment. Enthalpic Interaction Coefficients in Water and in N,N-Dimethylformamide at 25 deg C
Kent, Hilary E.,Lilley, Terence H.,Milburn, Peter J.,Bloemendal, Michael,Somsen, Gus
, p. 101 - 116 (1985)
Enthalpies of dilution of the N-acetyl amides of glycine, L-alanine, L-valine, L-leucine, and L-phenylalanine, dissolved in N,N-dimethylformamide (DMF) as a solvent have been measured at 25 deg C.The results obtained have been analyzed to give the enthalpic interaction (or virial) coefficients of the solutes and these are compared with information previously obtained in aqueous systems.There are marked differences in the interaction properties in the two solvents and, while the additivity approache of Savage and Wood is applicable to the solutes in water it is suitable for representing the interactions in DMF.A correlation is presented between the enthalpic second virial coefficients in DMF and the propensity of side-chains to be in proximity in globular proteins.
Cyclodextrin-mediated deacylation of amino acid esters with marked stereoselectivity.
Goto, Koichi,Nakashima, Kentaro,Tanoue, Osamu,Nukushina, Satoshi,Toudo, Isao,Imamura, Chikara,Ihara, Yasuji,Matsumoto, Yoko,Ueoka, Ryuichi
, p. 1283 - 1285 (2002)
With respect to the hydrolysis (deacylation) of Z-D(L)-amino acid esters (N-(benzyloxycarbonyl)-D(L)-amino acid p-nitrophenyl esters) mediated by alpha-, beta- and gamma-cyclodextrins (CyDs), a remarkably high enantioselectivity (L/D=9.0) was observed for the deacylation of Ala substrate with gamma-CyD. The kinetic results on the basis of the Michaelis-Menten principle indicate that the enantioselectivity should be mainly originated in the deacylation process of substrates following the formation of gamma-CyD-substrate (1 : 1) complexes. The computer modeling (molecular mechanics) studies on the inclusion complexes are also described.
STEREOSELECTIVE HYDROLYSIS OF AMINO ACID ESTERS BY MODIFIED POLY(ETHYLENIMINE)S WITH COVALENTLY-LINKED DIPEPTIDE CONTAINING A HISTIDYL RESIDUE
Kimura, Yoshiharu,Nango, Mamoru,Ihara, Yasuji,Kuroki, Nobuhiko
, p. 429 - 432 (1984)
Stereoselective hydrolyses of chiral substrates were examined in poly(ethylenimine) derivatives with optically active groups.A high stereoselective effect, kL/kD = 3.6, is observed.The effect of the substrate structure influenced both the rate constant and the stereoselective ratio in the hydrolyses by poly(ethylenimine) derivatives.
Overby et al.
, p. 2067 (1960)
STEREOSELECTIVE HYDROLYSIS OF AMINO ACID ESTERS IN MODIFIED LINEAR POLY(ETHYLENIMINE) DOMAINS
Kimura, Yoshiharu,Kanda, Shinichi,Nango, Mamoru,Ihara, Yasuji,Koga, Joichi,et al.
, p. 433 - 436 (1984)
A large rate enhancement and a stereoselective preference are exhibited in the hydrolysis catalysed by N-decanoyl-L-histidine (2a) and a dipeptide containing L-histidyl residue (2b) in the domain of linear poly(ethylimine) derivatives.
A General Stereocontrolled Synthesis of Opines through Asymmetric Pd-Catalyzed N-Allylation of Amino Acid Esters
Albat, Dominik,Neud?rfl, J?rg-Martin,Schmalz, Hans-Günther
supporting information, p. 2099 - 2102 (2021/07/22)
A stereo-divergent synthesis of natural and unnatural opines in stereochemically pure form is based on the direct palladium-catalyzed N-allylation of α-amino acid esters (up to 97 % ee or 99 : 1 d.r.) using methyl (E)-2-penten-4-yl carbonate in the presence of only 1 mol% of a catalyst, prepared in-situ from the C2-symmetric diphosphine iPr-MediPhos and [Pd(allyl)Cl]2. Selected target compounds (incl. a derivative of the drug enalapril) were efficiently obtained from the N-allylated intermediates by oxidative cleavage (ozonolysis) of the allylic C=C bond under temporary N-Boc-protection.
Synthesis, characterization and docking studies of anti-HCV molecules
Kumar, Satish,Santra,Dwivedi,Aryan
, p. 1221 - 1229 (2020/06/09)
The present study reports the synthesis and characterization of novel molecules inhibiting the spread of hepatitis C. The molecules were designed as to block the NS3/4A protease enzyme on HCV RNA. The molecules were synthesized using usual peptide synthesis techniques. Compounds with purity more than 95% were characterized and docking studies were also performed. All the compounds were characterized using physico-chemical techniques such as determination of melting point by DSC and NMR, mass, IR spectral studies. The docking studies were also conducted to assess the activity of molecules for inhibition of hepatitis C virus.
