1138-80-3Relevant articles and documents
Remarkable effects of donor esters on the α-chymotrypsin-catalyzed couplings of inherently poor amino acid substrates
Miyazawa, Toshifumi,Tanaka, Kayoko,Ensatsu, Eiichi,Yanagihara, Ryoji,Yamada, Takashi
, p. 997 - 1000 (1998)
The extremely low efficiency during the α-chymotrypsin-catalyzed coupling of an inherently poor amino acid substrate, e.g., alanine, using the methyl ester as an acyl donor was significantly improved using esters such as the 2,2,2-trifluoroethyl or carbamoylmethyl ester. The ameliorating effect of the latter ester was especially significant.
The reaction between C- and/or N-terminal protected α-aminoacid and sodium hydrogen telluride
Li,Zhou,Ma
, p. 553 - 559 (1995)
Sodium hydrogen telluride selectively removed C-terminal alkyl group of C- and/or N-terminal protected α-aminoacids with yields ranging from 70% to 95%.
Photoinduced release of neurotransmitter amino acids from coumarin-fused julolidine ester cages
Piloto, Ana M.,Hungerford, Graham,Costa, Susana P. G.,Goncalves, M. Sameiro T.
, p. 7715 - 7723 (2013)
The photoinduced release of several neurotransmitter amino acids (glycine, alanine, glutamic acid, β-alanine and γ-aminobutyric acid) was accomplished from ester cages based on a new photoremovable protecting group consisting of a coumarin built on the julolidine nucleus, namely a (11-oxo-2,3,5,6,7,11-hexahydro-1H-pyrano[2,3-f]pyrido[3,2,1-ij]quinolin-9-yl) methyl group. Photolysis and steady-state sensitization studies revealed that release of the active molecule occurred in short irradiation times at long wavelengths, with a very promising performance at 419 nm. Given the interest in the development of novel protecting groups that are cleavable with UV A or even visible radiation, it was found that a structural modification in the coumarin ring by assembly of a fused julolidine leads to a promising photolabile protecting group for organic synthesis and also for bioapplications. Photolysis and steady-state sensitization studies of several neurotransmitter amino acids from ester cages based on a new photoremovable protecting group consisting of a coumarin-fused julolidine nucleus, revealed that the release of the active molecule occurred in short irradiation times at long wavelengths, especially at 419 nm. Copyright
A novel immobilized chloroperoxidase biocatalyst with improved stability for the oxidation of amino alcohols to amino aldehydes
Pesic, Milja,Lopez, Carmen,Alvaro, Gregorio,Lopez-Santin, Josep
, p. 144 - 151 (2012)
Chloroperoxidase from Caldariomyces fumago (CPO, EC 1.11.1.10) is one of the most promising of the heme peroxidase enzymes for synthetic applications. Since the synthetic use of CPO suffers severely from its rapid deactivation in the presence of peroxides, the immobilization of this enzyme was studied as a possibility for stability improvement. Three methods of immobilization were considered using monoaminoethyl-N-aminoethyl (MANA) agarose gels: ionic adsorption, covalent attachment via carbodiimide coupled activation and covalent attachment of oxidized CPO. The most successful results led to almost complete immobilization with retained activities of around 51% for the two methods of covalent attachment and 77% for the ionic adsorption of CPO on MANA. Besides, all of the immobilized enzyme systems showed drastically improved stability toward presence of peroxide; CPO immobilized on MANA through carbodiimide coupled method resulted to be the most stable one with an increase in apparent half-life time of more than 500-fold that of the soluble enzyme. CPO immobilized by this method was compared to the soluble enzyme as catalyst for Cbz-ethanolamine oxidation to Cbz-glycinal using tert-butyl hydroperoxide (t-BuOOH) as an oxidant. Despite the lower reaction rate, the reaction catalyzed by immobilized CPO reached higher Cbz-glycinal yield with almost three-fold lower activity loss.
ACTION ON PEPTIDES BY WHEAT CARBOXYPEPTIDASE
Umetsu, H.,Ichishima, E.
, p. 591 - 592 (1983)
A kinetic analysis has been performed with purified wheat carboxypeptidase by the use of N-acyl dipeptides, Z-Gly-Pro-Leu-Gly (Z=benzyloxycarbonyl), angiotensin II and bradykinin.The values of kcat were dramatically influenced by amino acid residues occupying the penultimate position from the carbonyl terminus of substrates.The structure of the substrate did not appreciably affect the Km values. Key Word Index - Triticum aestivum; Gramineae; wheat; carboxypeptidase; peptides; kinetic parameters.
Scandium(III) triflate-promoted serine/threonine-selective peptide bond cleavage
Ni, Jizhi,Sohma, Youhei,Kanai, Motomu
, p. 3311 - 3314 (2017)
The site-selective cleavage of peptide bonds is an important chemical modification that is useful not only for the structural determination of peptides, but also as an artificial modulator of peptide/protein function and properties. Here we report site-selective hydrolysis of peptide bonds at the Ser and Thr positions with a high conversion yield. This chemical cleavage relies on Sc(iii)-promoted N,O-acyl rearrangement and subsequent hydrolysis. The method is applicable to a broad scope of polypeptides with various functional groups, including a post-translationally modified peptide that is unsuitable for enzymatic hydrolysis. The system was further extended to site-selective cleavage of a native protein, Aβ1-42, which is closely related to the onset of Alzheimer's disease.
15N NMR Spectroscopy; 24-Chemical Shifts and Coupling Constants of α-Amino Acid N-Carboxyanhydrides and Related Heterocycles
Kricheldorf, Hans R.
, p. 198 - 203 (1980)
The chemical shifts of amino acid N-carboxyanhydrides (NCAs) and cyclic or linear urethanes are less sensitive to solvent effects than those of amides and lactams.The values of the one-bond 15N-1H coupling constants depend on the solvent and are 5-8 Hz larger than those of ureas and amides.The 15N-13C coupling constant of the N-CO group is also unusually high, while that of the N-CH group lies within the range known for N-acetylated aliphatic amines.The one-bond 15N-13C coupling constant was found to be insensitive to conformational changes.
Synthesis, characterization, and DGAT1 inhibition of new 5-piperazinethiazole and 5-piperidinethiazole analogs
Kadam, Kishorkumar S.,Gandhi, Thirumanavelan,Reddy, M. Maheshkumar,Gupte, Amol,Sharma, Rajiv
, p. 802 - 814 (2015)
In this study, a novel series of 5-piperazinethiazole 2,2-dimethylbutanoic acid and 5-piperidinethiazole 2,2-dimethylbutanoic acid derivatives have been synthesized. Structures of the newly synthesized compounds have been elucidated using 1H-NMR, 13C-NMR, high-resolution mass spectroscopy, and high-performance liquid chromatographic analysis. The synthesized derivatives have been evaluated in vitro for their ability to inhibit the enzyme diacylglycerol acyltransferase 1 responsible for triglyceride biosynthesis.
First examples of bispidine-ferrocene cyclophanes
Churakov, A. V.,Gaisen, S. V.,Krut'ko, D. P.,Lemenovsky, D. A.,Medved'ko, A. V.,Minyaev, M. E.,Moiseeva, A. A.,Vatsadze, S. Z.,Wang, L.,Yu, H.
, (2021)
Two approaches for the syntheses of bispidine-ferrocene cyclophanes were reported. Both include the acylation of 1,5-dimethylbispidin-9-one (H2Bp) or its pendant amino-armed derivative by 1,1’-ferrocenoyl (Fc(CO)2) dichloride. The first approach allowed to isolate di-, tri- and pentameric cyclic oligomers of composition (BpFc(CO)2)n. The second one included the preliminary functionalization of H2Bp by N-protected glycine followed by deprotection and cyclization with Fc(COCl)2. The crystal structure of two new bispidine-ferrocene cyclophanes was established by single-crystal X-ray study. This study revealed the anti-conformation of amido-groups attached to the bispidine nitrogen atoms for both molecules. Various NMR techniques were applied to study the solution behavior of the macrocycles; the predominant anti-conformation in solution was also proved. The acyclic model compound Bp(FcCO)2 also showed only anti-conformer as revealed by VT-NMR and X-ray studies. Cyclic voltammetry study showed the difference in oxidation potentials of the Fc moiety within the row Bp(FcCO)2 – (BpFc(CO)2)2 – (BpFc(CO)2)3 with splitting of the oxidation curve in two later cases. The results obtained in this work will find an application in design and study of novel bispidine-ferrocene cyclophanes for the purposes of supramolecular sensing and catalysis.
Enzyme-Specific Activation versus Leaving Group Ability
de Beer, Roseri J.A.C.,Boegels, Berry,Schaftenaar, Gijs,Zarzycka, Barbara,Quaedflieg, Peter J.L.M.,van Delft, Floris L.,Nabuurs, Sander B.,Rutjes, Floris P.J.T.
, p. 1785 - 1790 (2012)
Enzyme-specific activation and the substrate mimetics strategy are effective ways to circumvent the limited substrate recognition often encountered in protease-catalyzed peptide synthesis. A key structural element in both approaches is the guanidinophenyl (OGp) ester, which enables important interactions for affinity and recognition by the enzyme-at least, this is usually the explanation given for its successful application. In this study we show that leaving group ability is of equal or even greater importance. To this end we used both experimental and computational methods: 1) synthesis of close analogues of OGp, and their evaluation in a dipeptide synthesis assay with trypsin, 2) molecular docking studies to provide insights into the binding mode, and 3) ab initio calculations to evaluate their electronic properties.
