- Ds-ERYTHRO-2-AMINO-4-ETHOXY-3-HYDROXYBUTANOIC ACID FROM THE FRUITING BODIES OF THE EDIBLE MUSHROOM, LYOPHYLLUM ULMARIUM
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A new β-hydroxy amino acid isolated from the fruiting bodies of Lyophyllum ulmarium was identified as Ds-erythro-2-amino-4-ethoxy-3-hydroxybutanoic acid by chemical degradation and spectroscopic analyses. Key Word Index - Lyophyllum ulmarium; Tricholomataceae; mushroom; amino acid; Ds-erythro-2-amino-4-ethoxy-3-hydroxybutanoic acid.
- Ogawa, Tadashi,Oka, Yoshiko,Sasaoka, Kei
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- Reaction of (S)-homoserine lactone with Grignard reagents: synthesis of amino-keto-alcohols and β-amino acid derivatives
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The ring-opening reaction of homoserine lactone with phenylmagnesium bromides was systematically examined. A reliable method to achieve β-amino acid precursors was developed by tuning the reaction conditions to favor mono-addition to the carbonyl moiety of the lactone.
- Gündo?du, ?zlem,Turhan, P?nar,K?se, Aytekin,Altunda?, Ramazan,Kara, Yunus
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- Large-scale, protection-free synthesis of Se-adenosyl-l-selenomethionine analogues and their application as cofactor surrogates of methyltransferases
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S-Adenosyl-l-methionine (SAM) analogues have previously demonstrated their utility as chemical reporters of methyltransferases. Here we describe the facile, large-scale synthesis of Se-alkyl Se-adenosyl-l-selenomethionine (SeAM) analogues and their precursor, Se-adenosyl-l-selenohomocysteine (SeAH). Comparison of SeAM analogues with their equivalent SAM analogues suggests that sulfonium-to-selenonium substitution can enhance their compatibility with certain protein methyltransferases, favoring otherwise less reactive SAM analogues. Ready access to SeAH therefore enables further application of SeAM analogues as chemical reporters of diverse methyltransferases.
- Bothwell, Ian R.,Luo, Minkui
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- Selective Inhibition of Benzyl Ether Hydrogenolysis with Pd/C Due to the Presence of Ammonia, Pyridine or Ammonium Acetate
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Ammonia, pyridine and ammonium acetate were found to be extremely effective as inhibitors of Pd/C catalyzed benzyl ether hydrogenolysis.While olefin, Cbz, benzyl ester and azide functionalities were hydrogenated smoothly, benzyl ethers were not cleaved in the presence of these additives.
- Sajiki, Hironao
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- Radiation chemical studies of methionine in aqueous solution: Understanding the role of molecular oxygen
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The oxidation of methionine is an important reaction in the biological milieu. Despite a few decades of intense studies, several fundamental aspects remain to be defined. We have investigated in detail the γ-radiolysis of free methionine in the absence and presence of molecular oxygen followed by product characterization and quantification. The primary site of attack by HO? radicals and H? atoms is the sulfur atom of methionine. We have disclosed that HO? radicals do not oxidize methionine to the corresponding sulfoxide in either the presence or the absence of oxygen; the oxidizing species is H2O2 derived either from the radiolysis of water or from the disproportionation of the byproduct O2?-. 3-Methylthiopropionaldehyde is the major product of HO? radical attack in the presence of molecular oxygen. Together with the direct oxidation at sulfur as the major product, the potential of H? atoms is also proven to be highly specific for sulfur atom attack under anoxic and aerobic conditions. The major products derived from the H? atoms attack are found to be α-aminobutyric acid or homoserine, in the absence or presence of oxygen, respectively. All together, these results help clarify the fate of methionine related to a biological environment and offer a molecular basis for envisaging other possible pathways of in vivo degradation as well as other markers.
- Barata-Vallejo, Sebastian,Ferreri, Carla,Postigo, Al,Chatgilialoglu, Chryssostomos
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- Concise Synthesis of Enantiomerically Pure (1′S,2′R)-and (1′R,2′S)-2S-Amino-3-(2′-aminomethyl-cyclopropyl)propionic Acid: Two E-Diastereoisomers of 4,5-Methano-l-lysine
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A concise synthesis of both E-isomers of 2S-amino-3-(2′-aminomethyl- cyclopropyl)propionic acid, new methano-l-lysines, is described. The synthetic route includes nine steps from l-methionine, with a key step involving the cyclopropanation of an intermediate E-allylic alcohol. The resultant hydroxymethylcyclopropanes were readily separated and converted into the title α-amino acids. The stereochemistry around the cyclopropane rings was deduced by conducting the cyclopropanation in the presence of N,N,N′,N′-tetramethyl-d-tartaric acid diamide butylboronate, a chiral controller which is known to favour the production of S-hydroxymethyl cyclopropanes from allylic alcohols.
- Altamore, Timothy M.,Nguyen, Oanh T. K.,Churches, Quentin I.,Cavanagh, Kate,Nguyen, Xuan T. T.,Duggan, Sandhya A. M.,Krippner, Guy Y.,Duggan, Peter J.
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- Synthesis of L-(+)-selenomethionine
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A novel three-pot synthesis of L-(+)-selenomethionine suitable for small and large scale preparations is presented. The method gives high optical purity and avoids evil smelling selenium species.
- Koch,Buchardt
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- Chemical approach for interconversion of (S)- and (R)-α-amino acids
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Here we report a general method for the preparation of unnatural (R)-α-amino acids via complexation of α-(phenyl)ethylamine derived chiral reagent (S)-3 with various (S)-α-amino acids. The reactions proceed with synthetically useful chemical yields and thermodynamically controlled diastereoselectivity. Chiral reagent (S)-3 can be conveniently recovered and reused without any loss of enantiomeric purity and reactivity. The Royal Society of Chemistry 2013.
- Sorochinsky, Alexander E.,Ueki, Hisanori,Ace?a, José Luis,Ellis, Trevor K.,Moriwaki, Hiroki,Sato, Tatsunori,Soloshonok, Vadim A.
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- Structure of the O-antigen of Acinetobacter lwoffii EK30A; Identification of d-homoserine, a novel non-sugar component of bacterial polysaccharides
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We established a peculiar structure of the O-specific polysaccharide (O-antigen) of a psychrotrophic strain of Acinetobacter lwoffii, EK30A, isolated from a 1.6-1.8 million-year-old Siberian permafrost subsoil sediment sample. The polysaccharide was released by mild acid degradation of the lipopolysaccharide and studied using chemical analyses, Smith degradation, 1H and 13C NMR spectroscopy and mass spectrometry. It was found to contain d-homoserine, which is N-linked to 4-amino-4,6-dideoxy-d- glucose (Qui4N) and is N-acylated itself with acetyl in about half of the repeating units or (S)-3-hydroxybutanoyl group in the other half. The following is the structure of the tetrasaccharide repeating unit of the polysaccharide: →3)-β-d-Quip4NAcyl-(1→6)-α-d-Galp-(1→4) -α-d-GalpNAc-(1→3)-α-d-FucpNAc-(1→ where Acyl stands for either N-acetyl- or N-[(S)-3-hydroxybutanoyl]-d-homoseryl. The Royal Society of Chemistry 2010.
- Arbatsky, Nikolay P.,Kondakova, Anna N.,Shashkov, Alexander S.,Drutskaya, Marina S.,Belousov, Pavel V.,Nedospasov, Sergei A.,Petrova, Mayya A.,Knirel, Yuriy A.
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- A selective method for sequential splitting of O- and N-linked glycans from N,O-glycoproteins
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O-linked oligosaccharides from N,O-glycoproteins were selectively split off by treatment with alkaline sodium borohydride in the presence of cadmium salt.The side reaction of reductive cleavage of N-glycosylamide and peptide bonds, observed under standard conditions of splitting of O-linked chains (M NaBH4 and 50mM NaOH, 16 h, 50 deg C), was inhibited by addition of 5-10 mM cadmium acetate and 5-10 mM EDTA*Na4, as shown by treatment of model compounds and several glycoproteins (ovomucoid, group-specific glycoproteins H and B, fetuin, and asialofetuin).This treatment,in combination with the previously developed prodcdure for the release of the N-linked oligosaccharide chains by lithium borohydride, allows a sequential, selective cleavage of O-, and then N-linked oligosaccharides from N,O-glycoproteins by chemical methods.
- Likhosherstov, Leonid M.,Novikova, Olga S.,Derevitskaya, Varvara A.,Kochetkov, Nikolay K.
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- Deracemization of amino acids by coupling transaminases of opposite stereoselectivity
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Biocatalytic deracemization of amino acids without relying on oxidase-based deamination of an unwanted enantiomer was demonstrated by coupling a-and w-transaminases displaying opposite stereoselectivity. This strategy employs isopropylamine and a keto acid as cosubstrates and is free of generation of hydrogen peroxide which is troublesome in the conventional oxidase-based methods.
- Park, Eul-Soo,Shin, Jong-Shik
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- N -acyl-homoserine lactones from enterobacter sakazakii (Cronobacter spp.) and their degradation by bacillus cereus enzymes
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A chemical study of acyl-homoserine lactones (acyl-HSLs) produced by Enterobacter sakazakii resulted in the identification of three molecules: (S)-N-heptanoyl-HSL, (S)-N-dodecanoyl-HSL and (S)-N-tetradecanoyl-HSL. Mixed cultures of E. sakazakii and Bacillus cereus depleted E. sakazakii acyl-HSLs, suggesting acyl-HSL degradation by B. cereus hydrolases (hydrolysis of the lactone or amide moiety). The expression of B. cereus acyl-HSL lactonase and acyl-homoserine acylase was confirmed by monitoring the biotransformation of (S)-N-dodecanoyl-HSL into (S)-N-dodecanoyl-homoserine, dodecanoic acid and homoserine in the presence of B. cereus whole cells, using electrospray-mass spectrometry (ESI-MS).
- Da Silva Araujo, Francisca Diana,Esper, Luciana Maria Ramires,Kuaye, Arnaldo Yoshiteru,Sircili, Marcelo Palma,Marsaioli, Anita Jocelyne
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- Combining Aldolases and Transaminases for the Synthesis of 2-Amino-4-hydroxybutanoic Acid
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Amino acids are of paramount importance as chiral building blocks of life, for drug development in modern medicinal chemistry, and for the manufacture of industrial products. In this work, the stereoselective synthesis of (S)- and (R)-2-amino-4-hydroxybutanoic acid was accomplished using a systems biocatalysis approach comprising a biocatalytic one-pot cyclic cascade by coupling of an aldol reaction with an ensuing stereoselective transamination. A class II pyruvate aldolase from E. coli, expressed as a soluble fusion protein, in tandem with either an S- or R-selective, pyridoxal phosphate dependent transaminase was used as a catalyst to realize the conversion, with formaldehyde and alanine being the sole starting materials. Interestingly, the class II pyruvate aldolase was found to tolerate formaldehyde concentrations of up to 1.4 M. The cascade system was found to reach product concentrations for (S)- or (R)-2-amino-4-hydroxybutanoic acid of at least 0.4 M, rendering yields between 86% and >95%, respectively, productivities of >80 g L-1 d-1, and ee values of >99%.
- Hernandez, Karel,Bujons, Jordi,Joglar, Jesús,Charnock, Simon J.,Domínguez De María, Pablo,Fessner, Wolf Dieter,Clapés, Pere
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- Synthesis of fluorinated analogues of sphingosine-1-phosphate antagonists as potential radiotracers for molecular imaging using positron emission tomography
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Sphingosine-1-phosphate (S1P) receptors play major roles in cardiovascular, immunological and neurological diseases. The recent approval of the sphingolipid drug Fingolimod (Gilenya), a sphingosine-1-phosphate agonist for relapsing multiple sclerosis, in 2010 exemplifies the potential for targeting sphingolipids for the treatment of human disorders. Moreover, non-invasive in vivo imaging of S1P receptors that are not available till now would contribute to the understanding of their role in specific pathologies and is therefore of preclinical interest. Based on fluorinated analogues of the S1P1receptor antagonist W146 showing practically equal in vitro potency as the lead structure, the first S1P receptor antagonist [18F]-radiotracer has been synthesized and tested for in vivo imaging of the S1P1receptor using positron emission tomography (PET). Though the tracer is serum stable, initial in vivo images show fast metabolism and subsequent accumulation of free [18F]fluoride in the bones.
- Prasad, Vysakh Pushpa,Wagner, Stefan,Keul, Petra,Hermann, Sven,Levkau, Bodo,Sch?fers, Michael,Haufe, Günter
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- Synthesis and delivery of a stable phosphorylated ubiquitin probe to study ubiquitin conjugation in mitophagy
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Protein post-translational modifications are involved in essentially all aspects of cellular signaling. Their dynamic nature and the difficulties in installing them using enzymatic approaches limits their direct study in human cells. Reported herein is the first synthesis, delivery and cellular study of a stable phosphoubiquitin probe. Our results compare Parkin's substrate preference during mitophagyviadirect visualization of a phosphorylated ubiquitin probe in the cellular environment.
- Mann, Guy,Satish, Gandhesiri,Sulkshane, Prasad,Mandal, Shaswati,Glickman, Michael H.,Brik, Ashraf
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supporting information
p. 9438 - 9441
(2021/09/22)
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- Rhodium(I) and Iridium(I) N-Heterocyclic carbene complexes of imidazolium functionalized amino acids and peptides
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The conjugation of organometallic complexes to peptides is generally achieved through covalent organic linkages of the metal's ligand to the peptide. Examples of direct coordination to metal centers by amino acid side chain residues remain rare. In one such example, side chain methylation of the natural amino acid histidine (His) resulted in an imidazolium functionalized amino acid which was used for the synthesis of rhodium(I), iridium(I), iridium(III), palladium(II) and ruthenium(III) N-heterocyclic carbene (NHC) complexes of the single amino acid and peptides containing this amino acid. Here, we have synthesized two new, non-natural imidazolium functionalized amino acid derivatives, which were used for solid phase peptide synthesis and for the synthesis of [M(COD)(NHC)Cl] (COD = 1,5 cyclooctadiene) complexes of Rh(I) and Ir(I). In total, six new complexes of the single amino acids and four complexes where the amino acids are present in a peptide environment were synthesized. Their characterization provides convincing evidence of conversion of the imidazolium moiety to an NHC ligand and thus the presence of a direct metal-carbon bond between the metal center and the amino acid side chain. Therefore, our compounds represent unique examples of peptide-conjugated complexes that bear the potential to be used for the synthesis of N-heterocyclic carbene complexes conjugated to cancer cell targeting peptides.
- Daubit, Isabelle Marie,Wolf, Jonas,Metzler-Nolte, Nils
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supporting information
(2020/01/13)
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- Design, synthesis, and evaluation of compounds capable of reducing Pseudomonas aeruginosa virulence
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Anti-virulence approaches in the treatment of Pseudomonas aeruginosa (PA)-induced infections have shown clinical potential in multiple in vitro and in vivo studies. However, development of these compounds is limited by several factors, including the lack of molecules capable of penetrating the membrane of gram-negative organisms. Here, we report the identification of novel structurally diverse compounds that inhibit PqsR and LasR-based signaling and diminish virulence factor production and biofilm growth in two clinically relevant strains of P. aeruginosa. It is the first report where potential anti-virulent agents were evaluated for inhibition of several virulence factors of PA. Finally, co-treatment with these inhibitors significantly reduced the production of virulence factors induced by the presence of sub-inhibitory levels of ciprofloxacin. Further, we have analyzed the drug-likeness profile of designed compounds using quantitative estimates of drug-likeness (QED) and confirmed their potential as hit molecules for further development.
- Hossain, Mohammad Anwar,Sattenapally, Narsimha,Parikh, Hardik I.,Li, Wei,Rumbaugh, Kendra P.,German, Nadezhda A.
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supporting information
(2019/11/26)
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- Method for synthesizing L L-(+)-selenomethionine (by machine translation)
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The synthetic route disclosed L - (+) - by the invention has, L - (+) - the advantages that the raw materials, are easy to obtain, the reaction conditions are, mild, the reaction conditions are mild, the separation, and purification are easy, L - (+) - and the; method L - (+) - is easy, to separate and purify L - (+) - L - (+) - L - (+) . (by machine translation)
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Paragraph 0041-0044; 0055; 0064; 0073; 0082
(2019/12/25)
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- Discovery of new A- and B-type laxaphycins with synergistic anticancer activity
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Two new cyclic lipopeptides termed laxaphycins B4 (1) and A2 (2) were discovered from a collection of the marine cyanobacterium Hormothamnion enteromorphoides, along with the known compound laxaphycin A. The planar structures were solved based on a combined interpretation of 1D and 2D NMR data and mass spectral data. The absolute configurations of the subunits were determined by chiral LC-MS analysis of the hydrolysates, advanced Marfey's analysis and 1D and 2D ROESY experiments. Consistent with similar findings on other laxaphycin A- and B-type peptides, laxaphycin B4 (1) showed antiproliferative effects against human colon cancer HCT116 cells with IC50 of 1.7 μM, while laxaphycins A and A2 (2) exhibited weak activities. The two major compounds isolated from the sample, laxaphycins A and B4, were shown to act synergistically to inhibit the growth of HCT116 colorectal cancer cells.
- Cai, Weijing,Matthew, Susan,Chen, Qi-Yin,Paul, Valerie J.,Luesch, Hendrik
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p. 2310 - 2319
(2018/04/02)
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- Identification of 2, 3-dihydrodipicolinate as the product of the dihydrodipicolinate synthase reaction from Escherichia coli
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Dihydrodipicolinate synthase (DHDPS) catalyzes the first step in the pathway for the biosynthesis of L-lysine in most bacteria and plants. The substrates for the enzyme are pyruvate and L-aspartate-β-semialdehyde (ASA). The product of the reaction was originally proposed to be 2,3-dihydrodipicolinate (DHDP), but has now generally been assumed to be (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinate (HTPA). ASA is unstable at high pH and it is proposed that ASA reacts with itself. At high pH ASA also reacts with Tris buffer and both reactions are largely reversible at low pH. It is proposed that the basic un-protonated form of the amine of Tris or the α-amine of ASA reacts with the aldehyde functional group of ASA to generate an imine product. Proton NMR spectra of ASA done at different pH values shows new NMR peaks at high pH, but not at low pH, confirming the presence of reaction products for ASA at high pH. The enzymatic product of the DHDPS reaction was examined at low pH by proton NMR starting with either 3 h-pyruvate or 3 d-pyruvate and identical NMR spectra were obtained with four new NMR peaks observed at 1.5, 2.3, 3.9 and 4.1 ppm in both cases. The NMR results were most consistent with DHDP as the reaction product. The UV-spectral studies of the DHDPS reaction shows the formation of an initial product with a broad spectral peak at 254 nM. The DHDPS reaction product was further examined by reduction of the enzymatic reaction components with borohydride followed by GC-MS analysis of the mixture. Three peaks were found at 88, 119 and 169 m/z, consistent with pyruvate, homoserine (reduction product of ASA), and the reduction product of DHDP (1,2,3,6-tetrahydropyridine-2,6-dicarboxylate). There was no indication for a peak associated with the reduced form of HTPA.
- Karsten, William E.,Nimmo, Susan A.,Liu, Jianguo,Chooback, Lilian
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- Microorganisms and methods for the biosynthesis of butadiene
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The invention provides non-naturally occurring microbial organisms having a butadiene pathway. The invention additionally provides methods of using such organisms to produce butadiene.
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- Synthesis of Chiral Bicyclic Guanidinium Salts using Di(imidazole-1-yl)methanimine
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A detailed account of the synthesis of chiral bicyclic guanidinium salts is presented. This work represents the first systematic investigation of an approach toward the challenging target molecules via a key guanylation step employing di(imidazole-1-yl)methanimine (6) followed by a two-fold cyclization, which resulted in guanidinium salts 8 and 10. Factors governing the regioselectivity of the final cyclization step are discussed based on further data obtained in the course of the attempted syntheses of two additional bicyclic guanidinium salts.
- Turo?kin, Aleksej,Honeker, Roman,Raven, William,Selig, Philipp
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p. 4516 - 4529
(2016/07/06)
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- FUNCTIONALIZED FLUORINE CONTAINING PHTHALOCYANINE MOLECULES
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Functionalized fluorine containing phthalocyanine molecules, methods of making, and methods of use in diagnostic applications and disease treatment are disclosed herein. In some embodiments, the fluorine containing phthalocyanine molecules are functionalized with a reactive functional group or at least one cancer-targeting ligand (CTL). The CTL can facilitate more efficient binding and/or internalization to a cancer cell than to a healthy cell. The CTL can inhibit expression of oncoprotein in some embodiments. The pthalocyanine moiety can be used in diagnostic applications, such as fluorescence labeling of a cancer cell, and/or treatment applications, such as catalyzing formation of a reactive oxygen species (ROS) which can contribute to cell death of a cancer cell.
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- Enantiopure azetidine-2-carboxamides as organocatalysts for direct asymmetric aldol reactions in aqueous and organic media
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A family of enantiopure azetidine-2-caboxamides was asymmetrically synthesized, and was examined as organocatalyst in direct aldol reactions. A well chosen chiral azetidine-2-caboxamide was found to smoothly catalyze the direct aldol reaction of various benzaldehydes with acetone in brine, and β-hydroxy ketones were produced with enantiomeric excess up to 96%. The reaction of benzaldehydes with cyclic ketones also led to the formation of anti-products in diastereomeric ratio up to 99:1 and enantiomeric excess up to 99%.
- Song, Xixi,Liu, Ai-Xiang,Liu, Shan-Shan,Gao, Wen-Chao,Wang, Min-Can,Chang, Junbiao
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p. 1464 - 1470
(2014/02/14)
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- MICROORGANISMS AND METHODS FOR THE BIOSYNTHESIS OF BUTADIENE
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The invention provides non-naturally occurring microbial organisms having a butadiene pathway. The invention additionally provides methods of using such organisms to produce butadiene.
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(2014/06/23)
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- Synthesis and biological evaluation of novel curcuminoid derivatives
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Curcuminoids have been reported to possess multiple bioactivities, such as antioxidant, anticancer and anti-inflammatory properties. Three novel series of curcuminoid derivatives (11a-h, 15a-h and 19a-d) with enhanced bioactivity have been synthesized. Among the synthesized compounds, 11b exhibited the most significant activity with an MIC of 0.5 μ M /mL against selected medically important Gram-positive cocci (S aureus and S viridans) and Gram-negative bacilli (E. coli and E. cloacae). The derivatives exhibited remarkable results in an antioxidant test with an IC50 2.4- to 9.3-folder smaller than curcuminoids. With respect to antiproliferative activity against Hep-G2, LX-2, SMMC7221 and MDA-MB-231, the derivatives exhibited an effect stronger than curcuminoids with an IC50 ranging from 0.18 to 4.25 μ M.
- Cao, Ya-Kun,Li, Hui-Jing,Song, Zhi-Fang,Li, Yang,Huai, Qi-Yong
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p. 16349 - 16372
(2015/01/08)
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- INTERMEDIATES OF SITAGLIPTIN AND PREPARATION PROCESS THEREOF
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Disclosed are intermediates of Sitagliptin, a preparation process thereof, and a process for synthesizing Sitagliptin using these intermediates. Sitagliptin is synthesized by using chiral amino compounds as a raw material, without having to build a chiral center with a chiral asymmetric catalytic hydrogenation, and high-pressure hydrogenation is avoided.
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Paragraph 0048; 0049
(2013/10/22)
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- INTERMEDIATES OF SITAGLIPTIN AND PREPARATION PROCESS THEREOF
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Disclosed are intermediates of Sitagliptin, a preparation process thereof, and a process for synthesizing Sitagliptin using these intermediates. Sitagliptin is synthesized by using chiral amino compounds as a raw material, without having to build a chiral center with a chiral asymmetric catalytic hydrogenation, and high-pressure hydrogenation is avoided.
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Paragraph 0094-0095
(2013/11/05)
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- METHOD FOR PREPARING AN AMINO ACID FROM 2 AMINOBUTYROLACTONE
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The invention relates to a method for preparing an amino acid, or its salts, from 2-aminobutyrolactone (2ABL), said amino acid fitting the formula I, XCH2CH2CHNH2COOH, wherein X is such that X? represents a nucleophilic ion, according to which N-carboxylation of 2-aminobutyrolactone (2ABL) is achieved with carbon dioxide, and the thereby obtained 2ABL carbamate is reactive with an XH reagent or its salts.
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Paragraph 0025; 0028
(2013/07/25)
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- PROCESSES FOR PREPARING AMINO-SUBSTITUTED GAMMA-LACTAMS
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The present application describes general process for the preparation of amino-substitued gamma-lactams involving the reaction of synthons of the general Formulae (I) and (VI): with amines. The processes are amenable to solid phase synthetic techniques and therefore allow the efficient incorporation of amino-substitued gamma-lactams into a wide variety of structural scaffolds, including, in particular peptides.
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Page/Page column 27
(2010/10/03)
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- Enantioselective synthesis of (2S,3′R,7′Z)-N -(3′-hydroxy-7′-tetradecenoyl)-homoserine lactone
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A concise enantioselective total synthesis of (2S,3′R,7′Z)-N- (3′-hydroxy-7′-tetradecenoyl)-homoserine lactone is described. Key feature of this protocol is a catalytic asymmetric hydrogenation and a prophenol-zinc-catalyzed diazo addition to imine reaction as genesis of chirality. Moreover, flexibility is built in the synthesis to generate enantioenriched analogs using catalytic amount of enantioenriched C 2-symmetric ligands.
- Kumaraswamy, Gullapalli,Jayaprakash, Neerasa
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supporting information; experimental part
p. 6500 - 6502
(2011/02/22)
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- Mycenaaurin A, an antibacterial polyene pigment from the fruiting bodies of mycena aurantiomarginata
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A new polyene pigment, mycenaaurin A (1), was isolated from fruiting bodies of Mycena aurantiomarginata. Mycenaaurin A consists of a tridecaketide that is flanked by two amino acid moieties. These are likely to be derived biosynthetically from S-adenosylmethionine. The tridecaketide itself contains an α-pyrone, a conjugated hexaene, and an isolated alkenyl moiety. The structure of the new pigment was established by 2D NMR spectroscopic methods and APCIMS. The absolute configuration of the four stereogenic centers was determined by degradation of 1 by ozonolysis and GC-MS comparison of the resulting fragments, after appropriate derivatization, with authentic synthetic samples. Mycenaaurin A (1) might act as a constitutive defense compound, since it exhibits antibacterial activity against the Gram-positive bacterium Bacillus pumilus.
- Jaeger, Robert J. R.,Spiteller, Peter
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experimental part
p. 1350 - 1354
(2010/10/21)
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- Positional scanning for peptide secondary structure by systematic solid-phase synthesis of amino lactam peptides
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Incorporation of amino lactams into biologically active peptides has been commonly used to restrict conformational mobility, enhance selectivity, and increase potency. A solid-phase method using a Fmoc-protection strategy has been developed for the systematic synthesis of peptides containing configurationally defined α- and β-amino γ-lactams. N-Alkylation of N-silyl peptides with five- and six-member cyclic sulfamidates 9 and 8 minimized bis-alkylation and provided N-alkyl peptides,which underwent lactam annulation under microwave heating. Employing th is solid-phase protocol on the growth hormone secretagogue GHRP-6, as well as on the allosteric modulator of the IL-1 receptor 101.10, has furnished 16 lactam derivatives and validated the effectiveness of this approach on peptides bearing aliphatic, aromatic, branched, charged, and heteroatomic side chains. The binding affinity IC 50 values of the GHRP-6 lactam analogues on both the GHS-R1a and CD36 receptors are reported as well as inhibition of thymocyte proliferation measurements for the 101.10 lactam analogues. In these cases, lactam analogues were prepared exhibiting similar or improved properties compared with the parent peptide. Considering the potential for amino lactams to induce peptide turn conformations, the effective method described herein for their supported construction on growing peptides, and for the systematical amino lactam scan of peptides, has proven useful for the rapid identification of the secondary structure necessary for peptide biological activity.
- Jamieson, Andrew G.,Boutard, Nicolas,Beauregard, Kim,Bodas, Mandar S.,Ong, Huy,et al.
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supporting information; experimental part
p. 7917 - 7927
(2009/10/16)
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- Structure-activity study of new inhibitors of human betaine-homocysteine S-methyltransferase
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Betaine-homocysteine S-methyltransferase (BHMT) catalyzes the transfer of a methyl group from betaine to L-homocysteine, yielding dimethylglycine and L-methionine. In this study, we prepared a new series of BHMT inhibitors. The inhibitors were designed to mimic the hypothetical transition state of BHMT substrates and consisted of analogues with NH, N(CH3), or N(CH 3)2 groups separated from the homocysteine sulfur atom by a methylene, ethylene, or a propylene spacer. Only the inhibitor with the N(CH3) moiety and ethylene spacer gave moderate inhibition. This result led us to prepare two inhibitors lacking a nitrogen atom in the S-linked alkyl chain: (RS,RS)-5-(3-amino-3-carboxypropylthio)-3-methylpentanoic acid and (RS)-5-(3-amino-3-carboxypropylthio)-3,3-dimethylpentanoic acid. Both of these compounds were highly potent inhibitors of BHMT. The finding that BHMT does not tolerate a true betaine mimic within these inhibitors, especially the nitrogen atom, is surprising and evokes questions about putative conformational changes of BHMT upon the binding of the substrates/products and inhibitors.
- Vaněk, Václav,Budě?ínsky, Milo?,Kabeleová, Petra,?anda, Miloslav,Koz?í?ek, Milan,Han?lová, Ivona,Mládková, Jana,Brynda, Ji?í,Rosenberg, Ivan,Koutmos, Markos,Garrow, Timothy A.,Jirá?ek, Ji?í
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supporting information; experimental part
p. 3652 - 3665
(2010/04/30)
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- Evaluation of enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl) methanol for catalytic asymmetric addition of organozinc reagents to aldehydes
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(Chemical Equation Presented) A facile and practical approach to preparation of enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)-methanol was developed from cheap and easily available L-(+)-methionine. Synthetic highlights include the three-step, one-pot construction of the chiral azetidine ring and the development of an improved one-step procedure for the synthesis of the key intermediate L-2-amino-4-bromobutanoic acid. Enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol was evaluated for catalytic asymmetric addition of organozinc reagents to aldehydes. The asymmetric ethylation, methylation, arylation, and alkynylation of aldehydes achieved enantioselectivity of up to 98.4%, 94.1%, 99.0%, and 84,6% ee, respectively, in the presence of a catalytic amount of chiral N-(ferrocenylmethyl)azetidin-2- yl(diphenyl)methanol. Our results demonstrated further that the four-membered heterocycle-based backbone was a good potential chiral unit for the catalytic asymmetric induction reaction, and the hindrance of the bulky ferrocenyl group, compared to a phenyl group, played an important role in the enantioselectivities. A possible transition for the catalytic asymmetric addition has been proposed on the basis of the crystal structure of the chiral ligand 3b including two HOAc molecules and previous studies.
- Wang, Min-Can,Zhang, Qing-Jian,Zhao, Wen-Xian,Wang, Xiao-Dan,Ding, Xue,Jing, Tao-Tao,Song, Mao-Ping
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p. 168 - 176
(2008/09/17)
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- Syntheses of the P-methylase substrates of the bialaphos biosynthetic pathway
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(Chemical Equation Presented) Genetic studies suggest that either N-acetyldemethyl phosphinothricin (1, N-AcDMPT) or N-acetyldemethyl phosphinothricin tripeptide (2, N-AcDMPTT) is the substrate for the P-methylation reaction in the biosynthesis of phosphinothricin tripeptide (PTT), which is widely used as an herbicide. To study the mechanism for this unique P-methylation reaction catalyzed by the BcpD protein and the functions of the unusual nonribosomal peptide synthetases involved in PTT biosynthesis, this work reports the chemical syntheses of 1 and 2.
- Xiao, Youli,Lee, Kent,Liu, Pinghua
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supporting information; experimental part
p. 5521 - 5524
(2009/06/28)
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- Process for producing alpha 2,3/ alpha 2,8-sialyltransferase and sialic acid-containing complex sugar
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The present invention can provide a process for producing a protein having α2,3/α2,8-sialyltransferase activity using a transformant comprising a DNA encoding a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism belonging to the genus Pasteurella and a process for producing a sialic acid-containing complex carbohydrate using a transformant capable of producing a protein having α2,3/α2,8-sialyltransferase activity derived from a microorganism.
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- Isoxazolinium salts in asymmetric synthesis. 1. Stereoselective reduction induced by a 3′-alkoxy stereocentre. A new approach to polyfunctionalized β-amino acids
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A new approach to optically active N-methylamino acids is presented, relying on stereoselective reduction of N-methylisoxazolinium salts with a dioxyethyl side-chain. The diastereoselectivity of the reduction step is studied systematically, in comparison with that of respective isoxazolines. A two-step transformation of isoxazolinium salts - with NaBH3(OAc) and subsequent catalytic hydrogenation as well as a one-pot reduction by catalytic hydrogenation led to high (95:5 and 87:13) diastereomeric ratios of protected erythro-N-methylaminopentanetriols. The hydroxyethyl side-chain is elaborated by oxidation to afford the β-N-methylamino acid 37, exemplifying the potential of this strategy.
- Henneb?hle, Marco,Le Roy, Pierre-Yves,Hein, Matthias,Ehrler, Rudolf,J?ger, Volker
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p. 451 - 467
(2007/10/03)
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- Stable organophosphorus analogues of S-adenosylmethionine and S-methylmethionine
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The organophosphorus analogues of the biologically significant sulfonium compounds S-adenosylmethionine and S-methylmethionine are much more stable than their carboxylic prototypes.
- Alferov, Kirill V.,Zhukov, Yurii N.,Khurs, Elena N.,Khomutov, Radii M.
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p. 243 - 244
(2007/10/03)
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- Gene recombinant antibody and antibody fragment thereof
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A recombinant antibody or the antibody fragment thereof which specifically reacts with an extracellular domain of human CCR4; a DNA which encodes the recombinant antibody or the antibody fragment thereof; a method for producing the recombinant antibody or the antibody fragment thereof; a method for immunologically detecting CCR4, a method for immunologically detecting a cell which expressed CCR4 on the cell surface, a method for depleting a cell which expresses CCR4 on the cell surface, and a method for inhibiting production of Th2 cytokine, which comprise using the recombinant antibody according or antibody fragment thereof; a therapeutic or diagnostic agent for Th2-mediated immune diseases; and a therapeutic or diagnostic agent for a blood cancer.
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- Reversal of diastereofacial selectivity in the nucleophilic addition reaction to chiral N-sulfinimine and application to the synthesis of indrizidine 223AB
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Diastereoselective addition reaction of ester enolates and Grignard reagents to optically active N-sulfinimines was examined. Reversal of the diastereofacial selectivity was realized by using appropriate metal species, solvents and additives, and the β-amino esters (up to >98% de) and the homoallylic amines (up to >98% de) were obtained in good yields. β-Amino esters thus obtained were converted to the useful β-amino acids involving (R)-homoserine. Application to the synthesis of indrizidine alkaloids was also described.
- Koriyama, Yuji,Nozawa, Akihiro,Hayakawa, Ryuuichirou,Shimizu, Makoto
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p. 9621 - 9628
(2007/10/03)
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- Under-flame Reaction of Sulfur-containing Amino Acids by a Hydrogen-Oxygen Flame
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Methionine was subjected to a flame-induced reaction in water or in an aqueous formic acid solution by using a hydrogen (50%)-oxygen (50%), hydrogen (87%)-oxygen (13%) and hydrogen diffusion flame. Besides the already-known stepwise oxidation by a hydroxyl radical, the contribution of a hydrogen atom from the flame to the reaction was recognized when the hydrogen-rich mixtures were employed. Homoserine was obtained under all the reaction conditions employed here, and glutamic acid when employing aqueous formic acid as a solvent. A common intermediate, the 3-carboxy-3-aminopropyl radical, appeared to exist in the reaction pathway. A coupling reaction of this radical with a hydrogen atom, hydroxyl radical and hydroxycarbonyl radical afforded 2-aminobutyric acid, homoserine and glutamic acid, respectively. Lanthionine and S-methylcysteine underwent the same reactions. Increasing the hydrogen content of the fuel and adding formic acid to the solvent resulted in retarding the reaction rate. The latter modification of the reaction system also brought about greater stability of the reaction products.
- Nomoto, Shinya,Shimoyama, Akira,Shiraishi, Susumu,Seno, Tomoyuki,Sahara, Denzo
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p. 643 - 649
(2007/10/03)
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- Synthetic gene coding for human parathyroid hormone
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Disclosed are (1) a DNA containing a synthetic gene for expression of human parathyroid hormone represented by the following DNA sequence:TCTGTG TCCGAGATTC AGTTAATGCA TAACCTTGGC AAACATTTGA ACTCCATGGA GCGTGTAGAA TGGCTGCGTA AGAAGTTGCA GGATGTGCAC AATTTTGTTG CCTTAGGTGC CCCATTGGCT CCTCGTGATG CTGGTTCCCA AAGACCACGT AAAAAGGAAG ACAATGTCTT AGTTGAGAGC CATGAAAAAT CCCTAGGCGA GGCAGACAAG GCCGATGTGA ATGTATTAAC TAAAGCTAAA TCCCAG(2) a method for producing the DNA described in (1), which comprises enzymatically ligating a plurality of oligodeoxynucleotides to one another to form the DNA and inserting the DNA into a vector if necessary, (3) a transformant transformed by the DNA described in (1), and (4) a method for producing human parathyroid hormone which comprises cultivating the transformant described in (3), accumulating human parathyroid hormone in a culture medium, and collecting the same, whereby hPTH can be allowed to express in large amounts in a system using E. coli as a host.
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- Flame-induced reactions of sulfur-containing amino acids in an aqueous solution
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Hydrogen-oxygen flames, when blown against an aqueous solution of methionine, induced conversion reactions to homoserine, 2-aminobutyric acid and glutamic acid. Besides the already-known reactions by a hydroxyl radical, a contribution of a hydrogen atom from hydrogen-rich flames to the reaction was recognized. We successfully controlled the vigorous oxidation of the system using a radical scavenger.
- Nomoto, Shinya,Shimoyama, Akira,Shiraishi, Susumu
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p. 1009 - 1012
(2007/10/03)
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- Cosmetic composition
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A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamine derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
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- Synthesis of (2S)-O-phosphohomoserine and its C-2 deuteriated and C-3 chirally deuteriated isotopomers: Probes for the pyridoxal phosphate-dependent threonine synthase reaction
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A short efficient synthesis of the threonine synthase substrate (2S)-O-phosphohomoserine and its C-2 deuteriated and C-3 chirally deuteriated isotopomers is described. The synthetic route also provides access to (2S)-homoserine and its C-2 deuteriated and C-3 chirally deuteriated isotopomers in high yield. Preliminary deuterium isotope effect determinations performed using the deuteriated (2S)-O-phosphohomoserines and threonine synthase from E. coli indicate that the removal of protons from both C-2 and C-3 is kinetically important.
- Barclay, Fiona,Chrystal, Ewan,Gani, David
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p. 683 - 689
(2007/10/03)
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- Optical resolution by preferential crystallization of (RS)-α-amino-γ-butyrolactone hydrochloride
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(RS)-α-Amino-γ-butyrolactone hydrochloride [(RS)-ABL·HCl] was found to exist as a conglomerate based on the infrared spectrum, solubility, and melting point. Optical resolution by preferential crystallization of (RS)-ABL·HCl was achieved to yield (R)- and (S)-ABL·HCl. The obtained (R)- and (S)-ABL·HCl were recrystallized, taking into account the solubility of (RS)-ABL·HCl to give optically pure (R)- and (S)-ABL·HCl.
- Shiraiwa, Tadashi,Miyazaki, Hideya,Ohta, Atsushi,Waki, Yukitaka,Yasuda, Masahiro,Morishita, Toshimitsu,Kurokawa, Hidemoto
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p. 2322 - 2325
(2007/10/03)
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- Synthesis of (S)-2-amino-1,1-diphenylbutan-4-ol; conversion of an α-amino acid into an α-(diphenylmethyl) amine without loss of optical purity
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The title amino-alcohol 4 is an intermediate for the preparation of chiral bicyclic amidines and guanidines, and also for polyamines with potential as ligands in enantioselective catalysis. It has been synthesized from (S)-methionine 1 via (S)-homoserine lactone 2 and amino-diol 3. Hydrogenolysis of the doubly benzylic hydroxyl group in 3 proved non-trivial, but was eventually achieved through the application of catalytic transfer methodology to the bis-acetyl derivative 14.
- Boyle,Davis,Dempsey,Hosken
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p. 2819 - 2828
(2007/10/03)
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- Synthesis of L-O-Phosphohomoserine and its C-3 Chirally Deuteriated Isotopomers: Probes for the Pyridoxal Phosphate Dependent Threonine Synthase Reaction
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A short efficient synthesis of the threonine synthase substrate L-O-phosphohomoserine and its C-3 chirally deuteriated isotopomers is described; the route also provides access to L-homoserine and its C-3 chirally deuteriated isotopomers in high yield.
- Barclay, Fiona,Chrystal, Ewan,Gani, David
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p. 815 - 816
(2007/10/02)
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- Optically active ester derivatives, preparation process thereof, liquid crystal materials and a light switching element
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Disclosed are herein optically active ester derivatives represented by the formula (I): STR1 (wherein R1 represents an alkyl group having 3 to 20 carbon atoms; R2 represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; X represents --COO-- or --OCO--; l represents a number of 1 or 2; k and m each represents a number of 0 or 1; n represents a number of 1 to 6), preparation processes therefor, liquid crystal materials containing such ester derivatives as active ingredient, and a light switching element using said liquid crystal materials as liquid crystal element.
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- Novel spergualin-related compounds and compositions
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The present invention relates to novel spergualin-related compounds represented by the general formula [I]: STR1 wherein X is --(CH2)1?5 or STR2 Y is a hydrogen atom or a residue obtained by removing a hydroxyl group from the carboxyl group of an amino acid or a peptide; m is 0, 1 or 2 and n is 1 or 2, with the proviso that Y is not a hydrogen atom when n is 2 and m is 0. This compounds are stable and exhibit a high immunosuppressive activity.
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