2458-78-8Relevant academic research and scientific papers
Visible-Light Mediated Tryptophan Modification in Oligopeptides Employing Acylsilanes
Reimler, Jannik,Studer, Armido
supporting information, p. 15392 - 15395 (2021/10/04)
A method for the selective tryptophan modification and labelling of tryptophan-containing peptides is described. Photoirradiation of acylsilanes generates reactive siloxycarbenes which undergo H?N-insertion into the indole moiety of tryptophan to give stable silyl protected hemiaminals. This method is successfully applied to chemically modify various tryptophan containing oligopeptides. The method enables the selective introduction of alkynes to peptides that are eligible for further alkyne-azide click chemistry. In addition, the dansyl fluorophore can be conjugated to a peptide using this approach.
L-threonine-linked dihydroartemisinin-fluoroquinolone conjugates, intermediates thereof, and preparation methods and uses of conjugates and intermediates
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Paragraph 0113; 0115; 0120, (2019/12/08)
The invention discloses L-threonine-linked dihydroartemisinin-fluoroquinolone conjugates represented by formula I, intermediates represented by formula II, preparation methods of the compounds of formula I and formula II, and uses of the compounds of the formula I in the preparation of drugs for resisting mycobacterium tuberculosis or/and drugs for lowering blood lipids.
Total Synthesis of Pseudomonas aeruginosa 1244 Pilin Glycan via de Novo Synthesis of Pseudaminic Acid
Liu, Han,Zhang, Yanfeng,Wei, Ruohan,Andolina, Gloria,Li, Xuechen
supporting information, p. 13420 - 13428 (2017/10/05)
Pseudaminic acid (Pse) is a nonulosonic acid unique to bacterial species, found as a component of important cell surface glycans and glycoproteins in various pathogenic species, such as the critical hospital threat Pseudomonas aeruginosa. Herein we present the development of a facile and scalable de novo synthesis of Pse and its functionalized derivatives from easily available Cbz-l-allo-threonine methyl ester (16 steps in 11% yield). The key reactions in our de novo synthesis involve the diastereoselective glycine thioester isonitrile-based aldol-type reaction to create the 1,3-anti-diamino skeleton, followed by the Fukuyama reduction and the indium-mediated Barbier-type allylation. Moreover, we have studied the glycosylation of the Pse glycosyl donors and identified the structural determinants for its glycosylation diastereoselectivity, which enabled us to complete the total synthesis of P. aeruginosa 1244 pilin trisaccharide α-5NβOHC47NFmPse-(2→4)-β-Xyl-(1→3)-FucNAc.
PEPTIDOMIMETIC SOMATOSTATIN RECEPTOR SUBTYPE 2 LIGANDS AND PET IMAGING AGENTS
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Page/Page column 22-23, (2010/11/25)
The present invention is directed to compounds useful as peptidomimetics for binding and/or imaging somatostatin subtype 2 receptors, and compositions comprising the compounds. The present invention is also directed to methods of preparing radiolabeled pe
ANTI-ODOR COMPOSITIONS AND THERAPEUTIC USE
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, (2008/06/13)
This application discloses a composition comprising a malodor compound and an anti-odor ingredient effective for reducing the presence or production of malodor. The composition may be topically applied to a subject and is useful for cosmetic conditions, pharmaceutical indications, or other objectives.
A Versatile Chemo-Enzymatic Route to Enantiomerically Pure β-Branched α-Amino Acids
Roff, Geoffrey J.,Lloyd, Richard C.,Turner, Nicholas J.
, p. 4098 - 4099 (2007/10/03)
A series of diastereoisomers of β-methyl-β-phenylalanine analogues 1a?f have been prepared in enantiomerically pure form using a combination of chemo- and biocatalysis. Starting from l-threonine methyl ester 2, a range of β,β-disubstituted didehydroamino
Synthesis of erythro-α-Amino β-hydroxy Carboxylic Acid Esters by Diastereoselective Photocycloaddition of 5-Methoxyoxazoles with Aldehydes
Griesbeck, Axel G.,Bondock, Samir,Lex, Johann
, p. 9899 - 9906 (2007/10/03)
A new photoaldol route to α-amino-β-hydroxy carboxylic acid esters is initiated by the photocycloaddition of aromatic or aliphatic aldehydes to 5-methoxyoxazoles. The 4-unsubstituted 5-methyloxazole 1 gave the cycloadducts 8a-f in high yields and excellent exo-diastereoselectivities. Hydrolysis of 8a-f gives the N-acetyl α-amino-β-hydroxy esters 9a-f, which could be subsequently converted into the corresponding Z-didehydro α-amino acids 10a-f. Quartenary α-amino-β-hydroxy esters 12, 14, 16, 18, and 20, which are stable against dehydration, were obtained from the 4-alkylated 5-methoxyoxazoles 2-6, in most cases highly erythro-selective due to the high degree of stereocontrol (exo) at the photocycloaddition (to give 11, 13, 15, 17, and 19) level. The relative configurations of the N-acetyl α-amino-β-hydroxy esters were determined by NMR spectroscopy and comparison with chiral pool-derived compounds as well as by X-ray structure determination of the ester 23, formed by hydrolysis of the cycloadduct 22, derived from photocycloaddition of propionaldehyde to the isoleucine-derived oxazole 21.
Structure elucidation of Sch 20562, a glucosidic cyclic dehydropeptide lactone: The major component of W-10 antifungal antibiotic
Afonso, Adriano,Hon, Frank,Brambilla, Ray
, p. 383 - 397 (2007/10/03)
A novel bacterium designated as Aeromonas sp. W-10 produces the antibiotic W-10 complex which comprises of two major and several minor components. The two major components from this complex, Sch 20562 (1) and Sch 20561 (1a), are of biological interest in view of their potent antifungal activity. The chemical degradation studies utilized for the assignment of structure 1 for Sch 20562 are described here. Some of the noteworthy diversity of structural features in this glucosidic cyclic dehydrononapeptide lactone 1 are: an N-terminal (D)-β-hydroxymyristyl unit, three D-amino acid units, two (E)-α-aminocrotonyl units, and an O-α-D-glucosyl-N-methyl-L-allo-threonine unit. The structure determination of 1 utilized the selective cleavage of the dehydropeptide units by ozonolysis to form fragments that were sequenced by mass spectrometry. The stereochemistry of the amino acid units were assigned by isolation of the free amino acids from the hydrolysates of the fragments. The stereochemistry of the α-aminocrotonyl units and the glucosidic linkage were assigned by nmr spectroscopy and molecular rotation data.
ASYMMETRIC SYNTHESIS. PRACTICAL PRODUCTION OF D AND L THREONINE. DYNAMIC KINETIC RESOLUTION IN RHODIUM AND RUTHENIUM CATALYZED HYDROGENATION OF 2-ACYLAMINO-3-OXOBUTYRATES.
Genet, J.P.,Pinel, C.,Mallart, S.,Juge, S.,Thorimbert, S.,Laffitte, J.A.
, p. 555 - 567 (2007/10/02)
Enantioselective syntheses of D and L threonine are described.Racemic methyl and ethyl 2-acylamino-3-oxobutyrate 1 were synthesized from the corresponding acetoacetates 6 and then hydrogenated stereoselectively via dynamic kinetic resolution with various chiral P * P Rh(I) 8 and Ru(II) 10 catalysts to give syn optically active alcohols which could be converted by hydrolysis and treatment with propylene oxide into threonine.The best results were obtained using (-) CHIRAPHOS Ru and (+) BINAP Ru as catalysts, in the hydrogenation step leading respectively to D threonine (ee : 99percent) and L threonine (ee : 94percent) in 26-34percent overall yields.
