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Search for "tyrosine" in Full Text gives 135 result(s) in Beilstein Journal of Organic Chemistry.

Graphical Abstract
  • derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4
  • ; organocatalysis; serine; threonine; tyrosine; Introduction Any adept researcher within the field of organic synthetic chemistry will be mindful of the outstanding importance of amino acids as inexpensive chiral starting materials in the synthesis of a nearly infinite variety of synthetic end products. This
  • the copper salt with hydrogen sulfide. This methodology has subsequently been employed in a more generic sense as a preparative method for synthesis of acrylic side-chain derivatives of amino acids such as lysine, ornithine, tyrosine and serine [6][7][8], having modified the original technique by
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Published 08 Apr 2015

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

  • Qiu Sun,
  • Jörg Heilmann and
  • Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

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  • , various therapies targeted at interfering with this process were investigated [6]. The favored clinical targets are the VEGF receptors, which have led to the development and approval of monoclonal antibodies against VEGF and VEGF receptor tyrosine kinase inhibitors [3]. However, the existing therapy
  • neovascularization in vivo [39]. It was also shown that resveratrol directly inhibited bovine aorta endothelial cell proliferation, migration and tube formation in vitro [40]. Resveratrol has also been found to effectively interrupt VEGF-mediated tyrosine phosphorylation of vascular endothelial (VE)-cadherin and its
  • show in vitro anti-angiogenic activity with respect to Pazopanib in both HUVEC tube formation assay and the rat thoracic aorta ring test. They inhibited protein kinase B/Akt and ABL tyrosine kinase in the micromolar range. The preliminary structure–activity relationship is summarized in Figure 5. The
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Published 16 Feb 2015

Synthesis and biological evaluation of a novel MUC1 glycopeptide conjugate vaccine candidate comprising a 4’-deoxy-4’-fluoro-Thomsen–Friedenreich epitope

  • Manuel Johannes,
  • Maximilian Reindl,
  • Bastian Gerlitzki,
  • Edgar Schmitt and
  • Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2015, 11, 155–161, doi:10.3762/bjoc.11.15

Graphical Abstract
  • , the search for novel anticancer therapies is of high current interest. For instance, promising approaches such as targeted therapy with small molecule tyrosine kinase inhibitors [1][2] and active cancer immune therapy have emerged [3][4] with the latter one being particularly attractive in terms of
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Published 23 Jan 2015

Expanding the scope of cyclopropene reporters for the detection of metabolically engineered glycoproteins by Diels–Alder reactions

  • Anne-Katrin Späte,
  • Verena F. Schart,
  • Julia Häfner,
  • Andrea Niederwieser,
  • Thomas U. Mayer and
  • Valentin Wittmann

Beilstein J. Org. Chem. 2014, 10, 2235–2242, doi:10.3762/bjoc.10.232

Graphical Abstract
  • ), sodium fluoride (20 mM) (Ser/Thr phosphatase inhibitor), sodium orthovandadate (0.3 mM) (inhibitor for ATPase, tyrosine and alkaline phosphatases), complete X protease inhibitor (Roche) (1X), NaCl (300 mM), TrisHCl pH 7.4 (25 mM), EDTA (5 mM) (to chelate metal ions and reduce oxidation damage), O-(2
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Published 22 Sep 2014

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

  • Thilo Focken and
  • Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

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  • inhibitors (2000) Protein tyrosine phosphatases (PTPs) are part of a superfamily of enzymes that catalyze protein tyrosine dephosphorylation. They are key regulators in various, crucial kinase-dependent signal transduction pathways and act to counterbalance the kinases. In particular, PTP1B has attracted
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Published 13 Aug 2014

Carbohydrate PEGylation, an approach to improve pharmacological potency

  • M. Eugenia Giorgi,
  • Rosalía Agusti and
  • Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 1433–1444, doi:10.3762/bjoc.10.147

Graphical Abstract
  • by the use of a [3 + 2] cycloaddition reaction of an alkyne-bearing PEG reagent and an azide-functionalized tyrosine residue genetically incorporated on human superoxide dismutase-1 [30]. GlycoPEGylation, targeting carbohydrate sites, was conceived to produce a more homogeneous product with lower
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Published 25 Jun 2014

Automated solid-phase peptide synthesis to obtain therapeutic peptides

  • Veronika Mäde,
  • Sylvia Els-Heindl and
  • Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

Graphical Abstract
  • substitutions by alanine [124] or hydrophobic/ionic monomers [125] can help to identify key binding sites of peptides and their individual receptors. In addition, it is possible to perform cyclization [126] or modification of NPY with unnatural amino acids [127]. Cabrele et al. reported on a tyrosine methyl
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Published 22 May 2014

A catalyst-free multicomponent domino sequence for the diastereoselective synthesis of (E)-3-[2-arylcarbonyl-3-(arylamino)allyl]chromen-4-ones

  • Pitchaimani Prasanna,
  • Pethaiah Gunasekaran,
  • Subbu Perumal and
  • J. Carlos Menéndez

Beilstein J. Org. Chem. 2014, 10, 459–465, doi:10.3762/bjoc.10.43

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  • ; Introduction Chromones are widely present in nature, especially in the plant kingdom, and a wide variety of useful biological properties are associated with them [1][2]. Chromone derivatives act as effective tyrosine and protein kinase C inhibitors [3] and display antifungal [4][5], antimycobacterial [6
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Published 21 Feb 2014

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

  • Tatyana L. Pavlovskaya,
  • Fedor G. Yaremenko,
  • Victoria V. Lipson,
  • Svetlana V. Shishkina,
  • Oleg V. Shishkin,
  • Vladimir I. Musatov and
  • Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

Graphical Abstract
  • commutatа [4], mitraphylline from Uncaria tomentosa [5] and spirotryprostatines A and B from the secondary metabolites of Aspergillus fumigatus [6][7][8]. In particular, oxindole derivatives are well known as powerful anti-tumor agents due to their kinase inhibitory properties, especially as tyrosine kinase
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Published 09 Jan 2014

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

  • Marcus Baumann and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

Graphical Abstract
  • equivalent acid functional material can be prepared starting from tyrosine (1.78) via a dual protection of the amino acid unit as the methyl ester and the amine as the benzaldehyde imine (Scheme 14). This is then followed by analogous ether formation with the previously generated mesylate 1.74. Intermediate
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Published 30 Oct 2013

Non-cross-linked polystyrene-supported 2-imidazolidinone chiral auxiliary: synthesis and application in asymmetric alkylation reactions

  • Quynh Pham Bao Nguyen and
  • Taek Hyeon Kim

Beilstein J. Org. Chem. 2013, 9, 2113–2119, doi:10.3762/bjoc.9.248

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  • . Results and Discussion First, the 2-imidazolidinone chiral auxiliary 1 was prepared in the solution phase from the commercially available O-benzyl-L-tyrosine in four steps, as previously reported [18]. For the synthesis of our envisioned homogeneous polymer, we began to directly co-polymerize a pair of
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Published 15 Oct 2013

The chemistry of isoindole natural products

  • Klaus Speck and
  • Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

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  • subdivided into cytochalasins [41] (phenylalanine), chaetoglobosins [45][46] (tryptophan), aspochalasins [47] (leucine), pyrichalasins [48] (tyrosine) or alachalasins [49][50] (alanine). The biosynthesis of cytochalasans was established on the basis of various isotope labeling experiments using cytochalasin
  • –Spengler reaction of dopamine (99) with 4-hydroxyphenylacetaldehyde (100), both derived from L-tyrosine (98) (Scheme 11). After oxidation and O-methylation, which is carried out by S-adenosylmethionine (SAM), (S)-reticuline (101) is obtained. Oxidation of the N-methyl group to the iminium ion and
  • relationship between these three classes [87][96]. The biosynthesis of aristolochic acid I (117) was elucidated via labeling experiments and is depicted in Scheme 14 [97][98][99][100]. First, two molecules of the amino acid L-tyrosine (98) are transformed to (R)-orientaline (121) in a similar fashion as
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Published 10 Oct 2013

Flow synthesis of a versatile fructosamine mimic and quenching studies of a fructose transport probe

  • Matthew B. Plutschack,
  • D. Tyler McQuade,
  • Giulio Valenti and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 2022–2027, doi:10.3762/bjoc.9.238

Graphical Abstract
  • that accounts for both dynamic and static quenching. Free amino acids at high concentrations can also quench fluorophores. To access the propensity for NBDM to be quenched by amino acids, we measured fluorescence in the presence of varying concentrations of alanine, glutamine, lysine, tyrosine
  • , methionine and histidine. As expected, the amino acids lacking functionality known to quench fluorophores (alanine, glutamine and lysine) did not quench NBDM at concentrations as high as 50 mM. Interestingly, tyrosine did not quench NBDM fluorescence even at concentrations as high as 2 mM (solubility limit
  • for tyrosine). Methionine and histidine, however, did quench NBDM via a dynamic mechanism (Figure 4). Carbohydrate–carbohydrate and carbohydrate–aromatic ring interactions are well-known [29][30]. Based on these interactions, we hypothesized that abnormal fluorescence behavior may be exhibited at high
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Published 07 Oct 2013

The conjugation of nonsteroidal anti-inflammatory drugs (NSAID) to small peptides for generating multifunctional supramolecular nanofibers/hydrogels

  • Jiayang Li,
  • Yi Kuang,
  • Junfeng Shi,
  • Yuan Gao,
  • Jie Zhou and
  • Bing Xu

Beilstein J. Org. Chem. 2013, 9, 908–917, doi:10.3762/bjoc.9.104

Graphical Abstract
  • the hydrogel. Being thermally reversible and relatively sensitive to the temperature, the hydrogel of 1a exhibits excellent recovery properties (Supporting Information File 1, Figure S4) [64]. The hydrogelation of 1a also offers an opportunity to examine whether the attachment of a tyrosine phosphate
  • residue to 1a allows enzymatic hydrogelation. As a soluble precursor, 1c (15.0 mg) dissolves in water (1.0 mL) at pH 7.6. After being treated with alkaline phosphatase (5.0 U/mL), the solution of 1c quickly transforms to a clear hydrogel within one hour. Due to the additional tyrosine residue, 1d, however
  • ][66][67][68] that constitute the weakly cross-linked matrices of the hydrogel. The addition of a D-tyrosine phosphate residue to 1b affords the precursor 1e. Despite containing a D-tyrosine phosphate, 1e (0.8 wt %, pH 7.6) undergoes dephosphorylation in the presence of alkaline phosphatase (5.0 U/mL
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Published 10 May 2013

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

  • Vijayanand Chandrasekaran,
  • Katharina Kolbe,
  • Femke Beiroth and
  • Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

Graphical Abstract
  • of FimH FlexX [24][25][26], flexible docking and consensus scoring [27][28], as implemented in Sybyl 6.9 [29], was employed. Docking was based on two different X-ray structures of FimH. They differ in the conformation of the so-called tyrosine gate at the entrance of the CRD, formed by the side
  • chains of Y48 and Y137. One structure is crystallised in an “open-gate” conformation [9], another in the “closed-gate” conformation [10]. Affinity of any FimH ligand is improved when it exerts favourable interactions with the tyrosine gate of FimH. Thus, this substructure is an important feature of the
  • the CRD of the lectin, as expected, and furthermore, that in both cases the azobenzene moiety exerts effective interactions with the tyrosine gate involving both benzene rings. Regardless of whether the (E)- or the (Z)-form of 2 is complexed with FimH, favourable π–π interactions can be formed between
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Published 01 Feb 2013

Synthesis of 5-(ethylsulfonyl)-2-methoxyaniline: An important pharmacological fragment of VEGFR2 and other inhibitors

  • Miroslav Murár,
  • Gabriela Addová and
  • Andrej Boháč

Beilstein J. Org. Chem. 2013, 9, 173–179, doi:10.3762/bjoc.9.20

Graphical Abstract
  • -(ethylsulfonyl)-2-methoxy-1,3-dinitrobenzene (4a) have been precisely physicochemically characterised. Keywords: angiogenesis; pharmacophoric ligand; synthesis of 5-(ethylsulfonyl)-2-methoxyaniline; VEGFR2 tyrosine kinase inhibitors; Introduction 5-(Ethylsulfonyl)-2-methoxyaniline (5) is a starting material
  • . Compound 5 is used for the development of small organic compounds, i.e., modulators targeting a broad spectrum of important human protein receptors or enzymes, e.g., VEGFR2, EGFR, PDGFR, TEK kinase, ckit, EphB4, ErbB-2 receptor tyrosine kinase, cyclin-dependent kinases 2 and 4, neu receptor, polo-like
  • VEGFR2 receptor has been solved by X-ray crystallography and is available in the Protein Data Bank (PDB: 1Y6A). The complex 1Y6A contains the intracellular tyrosine kinase domain of the VEGFR2 receptor, which accommodates two conformers of the AAZ ligand [5]. Compound 5 is an important precursor for the
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Published 25 Jan 2013

Chemical modification allows phallotoxins and amatoxins to be used as tools in cell biology

  • Jan Anderl,
  • Hartmut Echner and
  • Heinz Faulstich

Beilstein J. Org. Chem. 2012, 8, 2072–2084, doi:10.3762/bjoc.8.233

Graphical Abstract
  • protected as tert-butyl ethers (tyrosine), tert-butyloxycarbonyl derivatives (lysine), trityl derivatives (cysteine, glutamine), and as (2,2,4,6,7-pentamethyl)dihydrobenzofuran-5-sulfonyl derivative (arginine). Coupling was performed by using a 4-fold excess of each of the protected amino acids and the
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Published 27 Nov 2012

Total synthesis and biological evaluation of fluorinated cryptophycins

  • Christine Weiß,
  • Tobias Bogner,
  • Benedikt Sammet and
  • Norbert Sewald

Beilstein J. Org. Chem. 2012, 8, 2060–2066, doi:10.3762/bjoc.8.231

Graphical Abstract
  • suggests four different fragments to be assembled in the total synthesis, named unit A–D (Figure 1). Unit A is an α,β-unsaturated δ-hydroxy acid that usually also contains a benzylic epoxide or a benzylic double bond. Unit B represents a chlorinated O-methyl-D-tyrosine derivative, while unit C is a β2
  • substituents at the D-tyrosine residue were crucial for high antimitotic activity [17][18]. Moore et al. patented the synthesis of fluorinated analogues of cryptophycin-1 and cryptophycin-52 [20]. In particular, derivative 3 was shown to retain biological activity (IC50 = 39 pM) and was active against the
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Published 23 Nov 2012

Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

  • H. Bauke Albada,
  • Alina-Iulia Chiriac,
  • Michaela Wenzel,
  • Maya Penkova,
  • Julia E. Bandow,
  • Hans-Georg Sahl and
  • Nils Metzler-Nolte

Beilstein J. Org. Chem. 2012, 8, 1753–1764, doi:10.3762/bjoc.8.200

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  • activities of the synAMPs (MIC values) were compared to those of GS(K2Y2) (Y = D-tyrosine), a gramicidin S analogue, and vancomycin, one of the last lines of defense against Staphylococcus infections. From the antibacterial activity screening, the two most active peptides were selected for further analysis
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Published 15 Oct 2012

Synthetic glycopeptides and glycoproteins with applications in biological research

  • Ulrika Westerlind

Beilstein J. Org. Chem. 2012, 8, 804–818, doi:10.3762/bjoc.8.90

Graphical Abstract
  • tyrosine residues form the “tyrosine gate” [134]. By π–π stacking interactions with the aromatic tyrosine residues, monovalent α-mannose ligands containing hydrophobic aglycons, have shown increased binding affinities [128][135][136]. Employing multivalent ligands, the binding affinity to FimH could be
  • with the FimH tyrosine gate; this effect was more pronounced by the divalent glycopeptides. In accordance with other studies, it could be concluded that the distance between the mannoside ligands was important, showing stronger inhibition for the divalent glycopeptide with a larger spatial ligand
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Published 30 May 2012

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

  • Raheleh Rezaei Araghi,
  • Carsten C. Mahrenholz,
  • Rudolf Volkmer and
  • Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

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  • single hydrophobic position with tyrosine (L15Y) in the YaLdEeEg mutant results in a significant reduction in the spot intensity compared to that of wt Acid-pp. As already discussed, despite the similarity in size between Phe and Tyr residues, they exhibit prominent differences in the coiled-coil
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Published 25 Apr 2012

Enantioselective supramolecular devices in the gas phase. Resorcin[4]arene as a model system

  • Caterina Fraschetti,
  • Matthias C. Letzel,
  • Antonello Filippi,
  • Maurizio Speranza and
  • Jochen Mattay

Beilstein J. Org. Chem. 2012, 8, 539–550, doi:10.3762/bjoc.8.62

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  • this purpose, the proton-bonded diastereomeric [V∙H∙G]+ complexes [G = tyrosine methyl ester (tyrOMe), and amphetamine (amph); Figure 7] were generated in the ESI source of an FT-ICR-MS to measure the kinetics of their ligand displacement towards the enantiomers of the neutral 2-aminobutane (B) (Table
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Published 12 Apr 2012

Aldol elaboration of 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridin-4-ones, masked precursors to acylpyridones

  • Raymond C. F. Jones,
  • Abdul K. Choudhury,
  • James N. Iley,
  • Mark E. Light,
  • Georgia Loizou and
  • Terence A. Pillainayagam

Beilstein J. Org. Chem. 2012, 8, 308–312, doi:10.3762/bjoc.8.33

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  • (Figure 1) is the common structural unit of a family of natural products with a range of interesting biological activities [1]. Examples are the pigments tenellin (2a) and bassianin (2b) from insect pathogenic fungus Beauveria bassiana [2][3], pyridovericin (2c) [4] (a tyrosine kinase inhibitor) and the
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Published 27 Feb 2012

Thermodynamic and kinetic stabilization of divanadate in the monovanadate/divanadate equilibrium using a Zn-cyclene derivative: Towards a simple ATP synthase model

  • Hanno Sell,
  • Anika Gehl,
  • Frank D. Sönnichsen and
  • Rainer Herges

Beilstein J. Org. Chem. 2012, 8, 81–89, doi:10.3762/bjoc.8.8

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  • tyrosine phosphatase, this role is taken by hydrogen bonding of the phosphate ion to the positively charged arginine side chain [11]. In the key step of the hydrolysis of pyrophosphate by the yeast phosphatase, two Mg2+ ions and arginine H-bonds assist the P–O bond cleavage [12]. A number of artificial
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Published 12 Jan 2012

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

  • Jan-Christoph Kehr,
  • Douglas Gatte Picchi and
  • Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

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  • amino acid biosynthesis [70]. The biosynthetic route was proposed to start with tryptophan and tyrosine. Two of the initial steps of the sunscreen synthesis were reproduced in vitro [71]. The ORF NpR1275 was confirmed to act as a tryptophan dehydrogenase, whereas p-hydroxyphenylpyruvic acid was proposed
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Published 05 Dec 2011
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