- Preparation method of 2-methylalanine
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The invention specifically discloses a preparation method of 2-methylalanine, belonging to the technical field of organic synthesis. The method comprises the following steps: condensing 2,2-dimethoxypropane serving as a raw material with tert-butyl sulfinamide or tert-butyl carbamate to generate Schiff base, then carrying out nucleophilic addition on the Schiff base and sodium cyanide or potassium cyanide under the action of phase transfer catalysis and ammonium chloride, and then adding acid to hydrolyze cyano groups so as to obtain 2-methylalanine. According to the invention, the used raw materials are easily to obtain and low in price; process flow is simple and convenient; reaction conditions are mild; requirements on equipment are low; total yield is as high as 80-83%; and the purity of the prepared 2-methylalanine is more than 99.6%.
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Paragraph 0040-0042
(2021/07/28)
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- Aziridine Formation by a FeII/α-Ketoglutarate Dependent Oxygenase and 2-Aminoisobutyrate Biosynthesis in Fungi
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Aziridine is a characteristically reactive molecule with increased bioactivity due to its strained ring structure. Here, we investigated the biosynthesis of 2-aminoisobutyric acid (AIB) in Penicillium, and successfully reconstituted the three-step biosynthesis from L-Val to AIB in vitro. This previously unknown aziridine formation pathway proceeded with the non-heme iron and α-ketoglutarate-dependent (FeII/αKG) oxygenase TqaL, followed by aziridine ring opening by the haloalkanoic acid dehalogenase (HAD)-type hydrolase TqaF, and subsequent oxidative decarboxylation by the NovR/CloR-like non-heme iron oxygenase TqaM. Furthermore, the X-ray crystal structure of the C?N bond forming FeII/αKG oxygenase TqaL was solved at 2.0 ? resolution. This work presents the first molecular basis for aziridine biogenesis, thereby expanding the catalytic repertoire of the FeII/αKG oxygenases. We also report the unique aziridine ring opening by a HAD-type hydrolase and the remarkable oxidative decarboxylation by a non-heme iron oxygenase to produce AIB.
- Abe, Ikuro,Awakawa, Takayoshi,Bunno, Reito,Mori, Takahiro
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p. 15827 - 15831
(2021/06/15)
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- General Synthesis of Amino Acid Salts from Amino Alcohols and Basic Water Liberating H2
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An atom-economical and environmentally friendly method to transform amino alcohols to amino acid salts using just basic water, without the need of pre-protection or added oxidant, catalyzed by a ruthenium pincer complex, is developed. Water is the solvent, the source of the oxygen atom of the carboxylic acid group, and the actual oxidant, with liberation of dihydrogen. Many important and useful natural and unnatural amino acid salts can be produced in excellent yields by applying this new method.
- Hu, Peng,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 6143 - 6146
(2016/06/09)
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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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- Meteorites as catalysts for prebiotic chemistry
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From outer space: Twelve meteorite specimens, representative of their major classes, catalyse the synthesis of nucleobases, carboxylic acids, aminoacids and low-molecular-weight compounds from formamide (see figure). Different chemical pathways are identified, the yields are high for a prebiotic process and the products come in rich and composite panels.
- Saladino, Raffaele,Botta, Giorgia,Delfino, Michela,Di Mauro, Ernesto
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p. 16916 - 16922
(2014/01/06)
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- Trichoderins, novel aminolipopeptides from a marine sponge-derived Trichoderma sp., are active against dormant mycobacteria
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Three new aminolipopeptides, designated trichoderins A (1), A1 (2), and B (3), were isolated from a culture of marine sponge-derived fungus of Trichoderma sp. as anti-mycobacterial substances with activity against active and dormant bacilli. The chemical structures of trichoderins were determined on the basis of spectroscopic study. Trichoderins showed potent anti-mycobacterial activity against Mycobacterium smegmatis, Mycobacterium bovis BCG, and Mycobacterium tuberculosis H37Rv under standard aerobic growth conditions as well as dormancy-inducing hypoxic conditions, with MIC values in the range of 0.02-2.0 μg/mL.
- Pruksakorn, Patamaporn,Arai, Masayoshi,Kotoku, Naoyuki,Vilchze, Catherine,Baughn, Anthony D.,Moodley, Prashini,Jacobs Jr., William R.,Kobayashi, Motomasa
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scheme or table
p. 3658 - 3663
(2010/09/17)
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- Asperelines A-F, peptaibols from the marine-derived fungus Trichoderma asperellum
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Fermentation of the marine-derived fungus Trichoderma asperellum, collected from the sediment of the Antarctic Penguin Island, resulted in the isolation of six new peptaibols named asperelines A-F (1-6), which are characterized by an acetylated N-terminus and a C-terminus containing an uncommon prolinol residue. Structures were determined by extensive 1D and 2D NMR (1H- 1H COSY, HMQC, HMBC, NOESY) spectroscopic data analysis combined with ESIMS/MS fragmentation. The absolute configurations of the amino acid residues possessing a chiral R-carbon and of the prolinol residue were determined to be L and S, respectively, using a new method of 1H NMR spectroscopic comparison of complexes formed between the chiral reagent Ru(D 4-Por*)CO and amino acids derived from the peptaibols with those formed with reference standards.
- Ren, Jinwei,Xue, Chunmei,Tian, Li,Xu, Minjuan,Chen, Jian,Deng, Zhiwei,Proksch, Peter,Lin, Wenhan
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experimental part
p. 1036 - 1044
(2011/02/28)
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- Growth Hormone Secretagogue Receptor 1A Ligands
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The present invention relates to new growth hormone secretagogue receptor 1A (GHS-R 1A) ligands, and pharmaceutical compositions comprising any of the new GHS-R1 A ligands. The ligands are suitable for a wide range of applications, and thus the present invention also relates to use of the GHS-R1 A ligands according to the present invention in the manufacture of a medicament for the treatment of an individual in need thereof. In another aspect, the present invention relates to a method of treatment of an individual in need thereof, comprising administering to said individual one or more of the GHS-R1A ligands disclosed herein, such as e.g. for treatment of cancer cachexia.
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- Versatile synthesis of free and N-benzyloxycarbonyl-protected 2,2-disubstituted taurines
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An effective and versatile method was developed to synthesize N-benzyloxycarbonyl-protected and free 2,2-disubstituted taurines. Several novel 2,2-disubstituted taurines, including aliphatic/aromatic and cyclic/acyclic derivatives, were obtained, which demonstrates the generality of this method. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Wang, Boyuan,Zhang, Wei,Zhang, Leilei,Du, Da-Ming,Liu, Gang,Xu, Jiaxi
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p. 350 - 355
(2008/09/18)
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- Influence of solvent viscosity on the rate of hydrolysis of dipeptides by carboxypeptidase Y
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The influence of solvent viscosity on the rate of enzymatic hydrolysis of a series of dipeptides (Z-Phe-Gly, Z-Phe-Sar, Z-Phe-Ala, Z-Phe-NMeAla, Z-Phe-Aib and Z-Phe-Pro) by carboxypeptidase Y was investigated. The effect of solvent viscosity on the enzymatic hydrolysis revealed that whereas all Kcat values decreased with viscosity, those of the N-alkyl peptides decreased more than those of the N-H peptides. The kinetic behaviour implies the involvement of conformational changes of the enzyme in terms of the 'induced-fit' process. Copyright
- Kanosue, Yoshifumi,Kojima, Satoshi,Ohkata, Katsuo
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p. 448 - 457
(2007/10/03)
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- Relationship between the hydrophobicity of dipeptides and the Michaelis-Menten constant Km of their hydrolysis by carboxypeptidase-Y and carboxypeptidase-A
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The enzymatic hydrolysis of dipeptides by carboxypeptidase-Y and carboxypeptidase-A was investigated. In the enzymatic hydrolysis of the dipeptides, a good linear relationship (r = 0.997 and 0.999) was found between the Michaelis-Menten constant (Km) and the hydrophobicity of the substrates evaluated from relative elution volume in reversed-phase HPLC. The correlation suggests that the hydrophobicity of the C-terminal amino acid is a major factor in governing the stability of the enzyme-substrate complex. The difference in the slope of the linear-regression lines seems to reflect the degree of relative hydrophobicity of the binding pockets in carboxypeptidase-Y and carboxypeptidase-A.
- Kanosue, Yoshifumi,Kojima, Satoshi,Hiraga, Yoshikazu,Ohkata, Katsuo
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p. 1187 - 1193
(2007/10/03)
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- Heterocyclic aromatic compounds usefuls as growth hormone secretagogues
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Heterocyclic aromatic compounds are provided which are useful in stimulating endogenous production or release of growth hormone and in treating obesity, osteoporosis (improving bone density) and in improving muscle mass and muscle strength.The heterocyclic aromatic compounds have the structure including pharmaceutically acceptable salts thereof and all stereoisomers thereof,wherein Xa is heteroaryl, preferably, ?and R1, R1a, R6, Y, Xb, A, B, Z, R3, R4, R4a, R5 and R5a are as defined herein.
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- Heterocyclic aromatic compounds useful as growth hormone secretagogues
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Heterocyclic aromatic compounds are provided which are useful in stimulating endogenous production or release of growth hormone and in treating obesity, osteoporosis (improving bone density) and in improving muscle mass and muscle strength. The heterocyclic aromatic compounds have the structure including pharmaceutically acceptable salts thereof and all stereoisomers thereof, wherein Xais heteroaryl, preferably, ?and R1, R1a, R6, Y, Xb, A, B, Z, R3, R4, R4a, R5and R5aare as defined herein.
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- Propargyloxycarbonyl (Poc) amino acid chlorides as efficient coupling reagents for the synthesis of 100% diastereopure peptides and resin bound tetrathiomolybdate as an effective deblocking agent for the Poc group
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Synthesis of short peptides using propargyloxycarbonyl amino acid chlorides as effective coupling reagents and polymer supported tetrathiomolybdate as an efficient deblocking agent are reported.
- Bhat, Ramakrishna G.,Sinha, Surajit,Chandrasekaran, Srinivasan
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p. 812 - 813
(2007/10/03)
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- Metal ion inhibition of nonenzymatic pyridoxal phosphate catalyzed decarboxylation and transamination
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Nonenzymatic pyridoxal phosphate (PLP) catalyzed decarboxylations and transaminations have been revisited experimentally. Metal ions are known to catalyze a variety of PLP-dependent reactions in solution, including transamination. It is demonstrated here that the rate accelerations previously observed are due solely to enhancement of Schiff base formation under subsaturating conditions. A variety of metal ions were tested for their effects on the reactivity of the 2-methyl-2-aminomalonate Schiff bases. All were found to have either no effect or a small inhibitory one. The effects of Al3+ were studied in detail with the Schiff bases of 2-methyl-2-aminomalonate, 2-aminoisobutyrate, alanine, and ethylamine. The decarboxylation of 2-methyl-2-aminomalonate is unaffected by metalation with Al3+, while the decarboxylation of 2-aminoisobutyrate is inhibited 125-fold. The transamination reaction of ethylamine is 75-fold slower than that of alanine. Ethylamine transamination is inhibited 4-fold by Al3+ metalation, while alanine transamination is inhibited only 1.3-fold. Metal ion inhibition of Schiff base reactivity suggests a simple explanation for the lack of known PLP dependent enzymes that make direct mechanistic use of metal ions. A comparison of enzyme catalyzed, PLP catalyzed, and uncatalyzed reactions shows that PLP dependent decarboxylases are among the best known biological rate enhancers: decarboxylation occurs 1018-fold faster on the enzyme surface than it does free in solution. PLP itself provides the lion's share of the catalytic efficiency of the holoenzyme: at pH 8, free PLP catalyzes 2-aminoisobutyrate decarboxylation by ～1010-fold, with the enzyme contributing an additional ～108-fold.
- Zabinski,Toney
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p. 193 - 198
(2007/10/03)
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- Novel fungal metabolites as cell wall active antifungals: Fermentation, isolation, physico-chemical properties, structure and biological activity
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Two novel antifungal compounds, 1 (SCH 466457), and 2 (SCH 466456), active in a cell wall assay, were isolated from the fermentation broth of an unidentified fungus. The active compounds were separated from the broth filtrate by adsorption on a macroreticular resin and were purified on reverse phase HPLC. Detailed mass spectrometric and NMR experiments and degradative studies helped in elucidating the structures of these compounds. The compounds were identified to be peptides containing amino acids such as alanine, aminoisobutyric acid, proline, leucine, valine, glycine and a previously identified β-keto acid, 2-methyl 3-oxotetradecanoic acid.5) Both compounds were active against Candida, dermatophytes and Aspergillus (Geometric Mean MIC's, 8.9, 20 and 16 μg/ml, and 64, 128 and 23 μg/ml, respectively for 1 and 2).
- Hegde,Silver,Patel,Gullo,Yarborough,Huang,Das,Puar,DiDomenico,Loebenberg
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- Peptides with an insulin-like action
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Peptides with an insulin-like action, of formula I: STR1 in which G is a hydrogen atom, an amino add residue, or a monosubstituted or polysubstituted amino acid; D is an amino acid residue, a phosphoamino acid residue, a monosaccharide residue, or a covalent bond; E is --NH--(CH2)n --NR52, a glycerol residue, or --NH--(CH2)p --R6 --R7 ; R1 is (C1 -C4)-alkyl or =O; R2 is a sulfhydryl protecting group, (C1 -C3)-alkyl, or a hydrogen atom; R3 and R4, independently of one another, are a hydrogen atom or methyl; R5, each being identical or different, is a hydrogen atom, 1 to 6 monosaccharide residues, or 1 to 6 monosubstituted or polysubstituted monosaccharide residues; R6 is O PO4 H, PO2 H, NHCOO, S or OCOO; R7 is a hydrogen atom, 1 to 6 monosaccharide residues, or 1 to 6 monosubstituted or polysubstituted monosaccharide residues; w is an integer 1 or 2; their preparation and use for treatment of diabetes mellitus or insulin-independent diabetes.
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- Furan-, pyrrole-, and thiophene-based siloxydienes for syntheses of densely functionalized homochiral compounds
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This review describes the methods of preparation and use of 2-(trimethylsiloxy)furan, N-(tert-butoxycarbonyl)-2-(tert-butyldimethylsiloxy)pyrrole, and certain substituted analogues and congeners, including novel 2-(tert-butyldimethylsiloxy)thiophene, to synthesize complex carbohydrates, azasugars, polyhydroxylated alkaloids, C-glycosylated α-amino acids, amino acids bearing quaternary chiral carbon atoms, and thiosugars. Especially emphasized is the preparation of enantiomerically pure compounds of biological interest. Some mechanistic insights are presented.
- Casiraghi,Rassu
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p. 607 - 626
(2007/10/02)
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- SYNTHESIS OF α-SUBSTITUTED α-AMINO ACIDS BY THE ALKYLATION OF 5-OXAZOLINONE DERIVATIVES
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Methods have been developed for the alkylation of 5-oxazolinone derivatives in DMF in the presence of K2CO3, KOH, or diisopropylethylamine and a phase transfer catalyst as well as for the preparation of α-methylphenylalanine, α-methylalanine, α-methylalanine, and the methyl ester of N-benzoyl-α-methylalanine.Increasing the initial concentration of the starting 5-oxazolinone in the reaction mixture leads to a sharp drop in the yield of reaction products due to side condensation reactions.The reaction of 2-phenyl-4-benzyl-5-oxazolinonewith ethyl iodide gave a dimer, mamely, 3-(benzoylamino)-3,5-dibenzylpyrrolidine-2,4-dione.
- Slavinskaya, V. A.,Sile, D. E.,Katkevich, M. Yu.,Korchagova, E. Kh.,Lukevits, E.
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p. 724 - 728
(2007/10/02)
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- GENERAL METHOD FOR THE ASYMMETRIC SYNTHESIS OF α-AMINO ACIDS VIA ALKYLATION OF THE CHIRAL NICKEL(II) SCHIFF BASE COMPLEXES OF GLYCINE AND ALANINE
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Nickel(II) complexes of Schiff bases derived from (S)-o-benzaldehyde and alanine (3), or (S)-O-benzophenone and alanine (4), or glycine (5) have been used for the asymmetric synthesis of α-amino acids under a variety of conditions.The method of choice consists of the reaction of the corresponding complex with the appropriate alkyl halide in DMF at 25 deg C using solid NaOH as a catalyst.Low diastereoselective excess (d.e.) is observed for the alkylation of complex (3) with benzyl bromide and allyl bromide.Large selectivity (80 percent) is observed for the alkylation of complex (4).Optically pure(R)- and (S)-O-benzyl-α-methyl-α-amino acids were obtained (70-90 percent) after the alkylated diastereoisomeric complexes had been seperated on SiO2 and hydrolysed with aqueous HCl.The initial chiral reagents were recovered (80-92 percent).The alkylation of complex (5) gave (S)-alanine, (S)-valine, (S)-phenylalanine, (S)-tryptophan, (S)-isoleucine, (S)-2-aminohexanoic acid, and 3,4-dimethoxyphenylalanine with optical yields of 70-92 percent.The optically pure α-amino acids were obtained after the separation of the alkylated diastereoisomeric complexes on SiO2.The stereochemical mechanism of the alkylation reaction is discussed.
- Belokon, Yuri N.,Bakhmutov, Vladimir I.,Chernoglazova, Nina I.,Kochetkov, Konstantin A.,Vitt, Sergei V.,et al.
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p. 305 - 312
(2007/10/02)
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- THE UNUSUAL CYCLIC PRODUCTS FROM TETRA- AND PENTA-PEPTIDES OF α-METHYLALANINE
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Tetra- and pentapeptides of α-methylalanine give with PCl5, SOCl2 etc. intermediates which, with or without loss of amino acids, lead to bi- and tricyclic products containing imidazole and piperazine rings through different routes.
- Ali, M. Y.,Khatun, Anowara
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p. 451 - 454
(2007/10/02)
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- Preparation of Optically Pure α-Methyl-α-amino Acids via Alkylation of the Nickel(II) Schiff Base of (R,S)-Alanine with (S)-2-N-(N'-Benzylprolyl)aminobenzaldehyde
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Chiral nickel(II) complexes of Ala with (S)-2-N-(N'-benzylprolyl)aminobenzaldehyde were alkylated with alkyl halides and the diastereoisomeric complexes formed were separated on SiO2; their decomposition led to the isolation of enantiomerically pure (R)- and (S)-α-alkyl-α-amino acids with recovery of the initial (S)-bba.
- Belokon', Yuri N.,Chernoglazova, Nina I.,Kochetkov, Constantin A.,Garbalinskaya, Natalia S.,Belikov, Vasili M.
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p. 171 - 172
(2007/10/02)
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- Structure of a Peptidal Antibiotic P168 produced by Paecilomyces lilacinus (Thom) Samson
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The peptide antibiotic P168 contained a new amino acid, (2S,4S)-2-amino-6-hydroxy-4-methyl-8-oxodecanoic acid (6) and an amine, (S)-N1,N1-dimethylpropane-1,2-diamine (4) along with other unusual amino acids.The structure of the peptide was determined as (I) by in-beam mass spectrometry.
- Isogai, Akira,Suzuki, Akinori,Tamura, Saburo,Higashikawa, Shizuo,Kuyama, Shimpei
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p. 1405 - 1411
(2007/10/02)
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- SYNTHESIS OF α-AMINOAMIDES AND α-AMINO ACIDS FROM α-AMINONITRILES
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The transformations of α-aminonitriles in the presence of water and manganese(IV) oxide were investigated for the case of 2-amino-2-methylpropionitrile and 2-amino-2-methylbutyronitrile.The conditions for highly selective synthesis of α-aminoamides and α-amino acids from the corresponding α-aminonitriles were determined.
- Zil'berman, E. N.,Eremeev, I. V.,Abramov, A. V.
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p. 1243 - 1247
(2007/10/02)
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- Antibacterial peptides
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It has been found that dipeptides containing a 3-fluoro-D-alanine N-terminus are powerful antibacterials and produce a highly useful synergistic effect with antibiotics.
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- Structure of Leucinostatin A, New Peptide Antibiotic from Paecilomyces lilacinus A-267
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A new antibiotic leucinostatin A was isolated from the culture filtrate of Paecilomyces lilacinus A-267 and its structure was elucidated by mass spectrometric and degradative methods.
- Mori, Yuji,Tsuboi, Makoto,Suzuki, Makoto,Fukushima, Kazutaka,Arai, Tadashi
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- The Formation of Amino Acids by the Reactions of Singlet NH with Several Carboxylic Acids
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The photolysis of hydrogen azide was studied in liquid acetic acid, propionic acid, and isobutyric acid at room temperature.The formation of amino acids was confirmed by the color reactions with ninhydrin and with chromotropic acid and by the NMR spectra.From the propionic acid, α- and β-alanine were formed in the ratio of 1.5.In the case of isobutyric acid, α- and β-aminoisobutyric acids were formed in the ratio of about 5.These results are explained by the insertion reaction of NH(a1Δ) into the C-H bonds of carboxylic acids.
- Tsunashima, Shigeru,Kitamura, Takashi,Sato, Shin
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p. 2869 - 2871
(2007/10/02)
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