- Method for Preparing Unnatural Amino Acids
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The present invention relates to a manufacturing method of unnatural amino acids and unnatural amino acids manufactured thereby. Specifically, the present invention relates to an asymmetric synthesis method which can manufacture unnatural amino acids having significantly high optical purity, and to the unnatural amino acids manufactured thereby. A manufacturing method of unnatural amino acids represented by chemical formula 6 or chemical formula 7 comprises the steps of: synthesizing a compound represented by chemical formula 4 or chemical formula 5; manufacturing a diol compound; and manufacturing a carboxylic acid compound.COPYRIGHT KIPO 2016
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Paragraph 0172; 0173; 0203; 0204
(2017/01/09)
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- Inhibition of tyrosine phenol-lyase by tyrosine homologues
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We have designed, synthesized, and evaluated tyrosine homologues and their O-methyl derivatives as potential inhibitors for tyrosine phenol lyase (TPL, E.C. 4.1.99.2). Recently, we reported that homologues of tryptophan are potent inhibitors of tryptophan indole-lyase (tryptophanase, TIL, E.C. 4.1.99.1), with Ki values in the low μM range (Do et al. Arch Biochem Biophys 560:20–26, 2014). As the structure and mechanism for TPL is very similar to that of TIL, we postulated that tyrosine homologues could also be potent inhibitors of TPL. However, we have found that homotyrosine, bishomotyrosine, and their corresponding O-methyl derivatives are competitive inhibitors of TPL, which exhibit Ki values in the range of 0.8–1.5?mM. Thus, these compounds are not potent inhibitors, but instead bind with affinities similar to common amino acids, such as phenylalanine or methionine. Pre-steady-state kinetic data were very similar for all compounds tested and demonstrated the formation of an equilibrating mixture of aldimine and quinonoid intermediates upon binding. Interestingly, we also observed a blue-shift for the absorbance peak of external aldimine complexes of all tyrosine homologues, suggesting possible strain at the active site due to accommodating the elongated side chains.
- Do, Quang,Nguyen, Giang T.,Phillips, Robert S.
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p. 2243 - 2251
(2016/08/26)
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- Comparisons of O-acylation and Friedel-Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: Effective synthesis of optically active homotyrosines
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Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel-Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH was required for effective C-acylations in mild condition. These results have been applied to the novel synthesis of homotyrosine derivatives. Both Fries rearrangement of N-TFA-Asp(OBn)-OMe and Friedel-Crafts acylation of phenol with N-TFA-Asp(Cl)-OMe in TfOH afforded the homotyrosine skeleton, followed by reduction and deprotection afforded homotyrosines maintaining stereochemistry of Asp as an optically pure form.
- Murashige, Ryo,Hayashi, Yuka,Ohmori, Syo,Torii, Ayuko,Aizu, Yoko,Muto, Yasuyuki,Murai, Yuta,Oda, Yuji,Hashimoto, Makoto
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p. 641 - 649
(2011/03/19)
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- Tiglicamides A-C, cyclodepsipeptides from the marine cyanobacterium Lyngbya confervoides
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The Floridian marine cyanobacterium Lyngbya confervoides afforded cyclodepsipeptides, termed tiglicamides A-C (1-3), along with their previously reported analogues largamides A-C (4-6), all of which possess an unusual tiglic acid moiety. Their structures
- Matthew, Susan,Paul, Valerie J.,Luesch, Hendrik
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experimental part
p. 2058 - 2063
(2010/07/04)
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- Homotyrosine-containing cyanopeptolins 880 and 960 and anabaenopeptins 908 and 915 from Planktothrix agardhii CYA 126/8
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Two homotyrosine-bearing cyanopeptolins are described from Planktothrix agardhii CYA 126/8. The compounds feature a common homotyrosine-containing cyclohexadepsipeptide and differ by sulfation of an exocyclically located 2-O-methyl-D-glyceric acid residue. In addition we describe two anabaenopeptins, which contain two homotyrosine residues, one of which is N-methylated. The anabaenopeptins have a common cyclopentapeptide portion and differ in the amino acid linked to it via an ureido bond, arginine and tyrosine, respectively.
- Okumura, Hilary S.,Philmus, Benjamin,Portmann, Cyril,Hemscheidt, Thomas K.
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supporting information; experimental part
p. 172 - 176
(2009/06/27)
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- Discovery, SAR, synthesis, pharmacokinetic and biochemical characterization of A-192411: A novel fungicidal lipopeptide-(I)
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The echinocandin class of cyclic lipopepetides has been simplified to discover potent antifungal compounds. Namely A-192411 shows good in vitro activity against common pathogenic yeasts and has an acceptable safety window in vivo. Discovery, limited SAR, synthesis, biochemical and pharmaco-dynamic profiles of A-192411 are presented.
- Wang, Weibo,Li, Qun,Hasvold, Lisa,Steiner, Beth,Dickman, Daniel A.,Ding, Hong,Clairborne, Akyio,Chen, Hui-Ju,Frost, David,Goldman, Robert C.,Marsh, Kennan,Hui, Yu-Hua,Cox, Brian,Nilius, Angela,Balli, Darlene,Lartey, Paul,Plattner, Jacob J.,Bennani, Youssef L.
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p. 489 - 493
(2007/10/03)
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- Enantioselective syntheses of homophenylalanine derivatives via nitrone 1,3-dipolar cycloaddition reactions with styrenes
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A new two-step route to derivatives of homophenylalanine is presented. Cycloaddition of a cyclic nitrone glycine template with various styrene derivatives affords good yields of 5-substituted cycloadducts. One-step hydrogenolysis (three bonds) then affords the optically pure α-amino acids related to homophenylalanine.
- Long, Alan,Baldwin, Steven W.
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p. 5343 - 5345
(2007/10/03)
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- Dose-response relations for unnatural amino acids at the agonist binding site of the nicotinic acetylcholine receptor: Tests with novel side chains and with several agonists
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Structure-function relations in the nicotinic acetylcholine receptor are probed using a recently developed method based on chemical synthesis of nonsense suppressor tRNAs with unnatural amino acid residues, site-directed incorporation at nonsense codons in Xenopus laevis oocytes, and electrophysiological measurements. A broad range of unnatural amino acids, as many as 14 at a given site, are incorporated at three sites, α93, α190, and α198, all of which are tyrosine in the wild-type receptor and are thought to contribute to the agonist binding site. Confirming and expanding upon earlier studies using conventional mutagenesis, the three tyrosines are shown to be in substantially different structural microenvironments. In particular, a crucial role is established for the hydroxyl group of α-Tyr93, whereas a variety of substituents are functional at the analogous position of αTyr198. Interestingly, consideration of three different agonists (acetylcholine, nicotine, and tetramethylammonium) does not discriminate between these two best-characterized binding site residues. In addition, double-mutation studies establish the independent effects of mutations at the pore region (second transmembrane region) and at the agonist binding site, and this observation leads to a novel strategy for adjusting EC50 values. These results establish the broad generality and great potential of the unnatural amino acid methodology for illuminating subtle structural distinctions in neuroreceptors and related integral membrane proteins.
- Kearney, Patrick C.,Nowak, Mark W.,Zhong, Wenge,Silverman, Scott K.,Lester, Henry A.,Dougherty, Dennis A.
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p. 1401 - 1412
(2007/10/03)
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