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Search for "tryptophan" in Full Text gives 104 result(s) in Beilstein Journal of Organic Chemistry.

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

  • Marcus Baumann,
  • Ian R. Baxendale and
  • Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

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  • chemistry; heterocycle; hydrogenation; indole; multistep; Introduction Indoles are amongst the most important bioactive heterocyclic structures being commonly encountered in the amino acid tryptophan (1), the related neurotransmitter serotonin (2) as well as numerous complex alkaloid natural products and
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Published 29 Nov 2017

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

  • Matthias Wünsch,
  • David Schröder,
  • Tanja Fröhr,
  • Lisa Teichmann,
  • Sebastian Hedwig,
  • Nils Janson,
  • Clara Belu,
  • Jasmin Simon,
  • Shari Heidemeyer,
  • Philipp Holtkamp,
  • Jens Rudlof,
  • Lennard Klemme,
  • Alessa Hinzmann,
  • Beate Neumann,
  • Hans-Georg Stammler and
  • Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

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  • % [21]. Synthesis of propargylamines containing electron-withdrawing substituents Aromatic and carbonyl substituents in the Cβ-position of propargylamines (occurring in analogoues of the amino acids phenylalanine, tyrosine, histidine, tryptophan, aspartic acid and asparagine) increase the acidity of the
  • imine 5h) after desilylation with TBAF (Table 2). As the benzylic proton of sulfinylimine 5h is quite acidic, approach II was not pursued for the synthesis of propargylamines analogous to tyrosine, histidine, tryptophan, and aspartate. Proteinogenic amino acids do not contain substituents, which
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Published 15 Nov 2017

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

  • Yaroslav D. Boyko,
  • Valentin S. Dorokhov,
  • Alexey Yu. Sukhorukov and
  • Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

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  • Ottenheijm in the total synthesis of an analogue of the tryptophan-containing natural alkaloid neoechinulin B (indole 77) [67][68] (Scheme 28). At the initial stage, N-methylindole was alkylated with ethyl bromopyruvate oxime and sodium carbonate to give adduct 78, which was then transformed into N
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Published 23 Oct 2017

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

  • Santanu Hati,
  • Ulrike Holzgrabe and
  • Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

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  • tryptophan derivatives with appropriate aldehydes. A hypervalent iodine reagent, iodobenzene diacetate was used in stoichiometric quantities to facilitate both oxidative decarboxylation/dehydrogenation of 108–110 to afford the desired natural products 111–113 (Scheme 42). Conclusion Substantial amount of
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Published 15 Aug 2017

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

  • Spyros D. Chatziefthimiou,
  • Mario Inclán,
  • Petros Giastas,
  • Athanasios Papakyriakou,
  • Konstantina Yannakopoulou and
  • Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

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  • expected to have restricted mobility and limited disorder. Indicative of the interest and possible applications of the CD use in chiral selectivity/discrimination of tryptophan are studies in aqueous solution [21], in electrochemistry for sensor development [17][22][23], as components of solid phases in
  • complexation (Supporting Information File 1, Figure S1). The inflection point of the graphs at 0.5 indicates a 1:1 stoichiometry for both enantiomers. The tryptophan protons were affected differently upon complexation (Supporting Information File 1, Figure S2), i.e., the graphs due to shifts of the indole’s
  • orientation of the guest inside the host and the formation of the crystals per se. Experimental Materials and methods N-Acetyl-L-tryptophan (L-NAcTrp), N-acetyl-D-tryptophan (D-NAcTrp) and β-CD were obtained from Sigma-Aldrich. Deuterium oxide was a product of Deutero GmbH. NMR spectroscopy The spectra were
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Published 09 Aug 2017

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and 3JHH coupling constant analyses

  • Weslley G. D. P. Silva,
  • Carolyne B. Braga and
  • Roberto Rittner

Beilstein J. Org. Chem. 2017, 13, 925–937, doi:10.3762/bjoc.13.94

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  • derivatives of tryptophan [20], phenylalanine and tyrosine [21], aspartic acid [22], proline [23] and histidine [24]. These studies have provided significant results to understand the importance of the corresponding amino acids in processes in which they take part in the polypeptide chain. Furthermore, these
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Published 17 May 2017

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

  • Katarina Kemper,
  • Max Hirte,
  • Markus Reinbold,
  • Monika Fuchs and
  • Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

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  • insights into cyclization mechanism but also lead to novel products or changes in the product spectra. This has also been demonstrated for the bacterial diterpene cyclooctat-9-en-7-ol synthase (CotB2) [57], also a putative Class I TPS. Mutation of tryptophan 288 to glycine in CotB2 resulted in the
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Published 08 May 2017

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

  • Stephen Hill and
  • M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

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  • overlap with the cell autofluorescence. Recent years have seen an increase in synthetic reports of large scale N-doped CDs with good QYs from carbohydrate starting materials. For example in 2014, Leitão et al. described the microwave synthesis of CDs using 2.5 g of glucose and 0.3 g of tryptophan as the N
  • properties are only observed below a diameter of 10 nm, which is not the case here and has since been observed in one other carbohydrate-derived CD synthesis [34]. The team demonstrated the utility of the glucose/tryptophan-derived CDs as a sensor of peroxynitrite anions (NO3−) in solution. The peroxynitrite
  • traditionally difficult to detect. The team was able to show significant quenching of the CDs via tryptophan oxidation of the exposed residues on the surface of CDs (Scheme 5). Post-oxidation fluorescence is compromised and therefore can be used as a signal for selectively sensing peroxynitrite up to
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Published 10 Apr 2017

Posttranslational isoprenylation of tryptophan in bacteria

  • Masahiro Okada,
  • Tomotoshi Sugita and
  • Ikuro Abe

Beilstein J. Org. Chem. 2017, 13, 338–346, doi:10.3762/bjoc.13.37

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  • the thiol groups of proteins in eukaryotes. In contrast, the Bacillus quorum sensing peptide pheromone, the ComX pheromone, possesses a posttranslationally modified tryptophan residue, and the tryptophan residue is isoprenylated with either a geranyl or farnesyl group at the gamma position to form a
  • tricyclic skeleton that bears a newly formed pyrrolidine, similar to proline. The post-translational dimethylallylation of two tryptophan residues of a cyclic peptide, kawaguchipeptin A, from cyanobacteria has also been reported. Interestingly, the modified tryptophan residues of kawaguchipeptin A have the
  • same scaffold as that of the ComX pheromones, but with the opposite stereochemistry. This review highlights the biosynthetic pathways and posttranslational isoprenylation of tryptophan. In particular, recent studies on peptide modifying enzymes are discussed. Keywords: Bacillus subtilis
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Published 22 Feb 2017

Phosphated cyclodextrins as water-soluble chiral NMR solvating agents for cationic compounds

  • Cira Mollings Puentes and
  • Thomas J. Wenzel

Beilstein J. Org. Chem. 2017, 13, 43–53, doi:10.3762/bjoc.13.6

Graphical Abstract
  • -indanol (23), tryptophan (24), tryptophan methyl ester (25), 1-methyltryptophan methyl ester (26), 1-(1-naphthyl)ethylamine (27), N,N-dimethyl-1-(1-naphthyl)ethylamine (28), propranolol (29), pheniramine (30), brompheniramine (31), doxylamine (32), and carbinoxamine (33) (Figure 2) in their protonated
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Published 06 Jan 2017

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

  • Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

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  • ., alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, cysteine and methionine), they can be easily included inside the CDs. This complexation leads to modification of the protein. For sake of clarity, only some typical examples are reported in this section. In their paper on the
  • whereas the opposite is true for the Me-α-CD. It should be noted that the thermal stability reduction is very important for G1-β-CD. Based on fluorescence spectroscopy, the authors suggested that CDs include the side chains of tryptophan (Trp) residues of lysozyme within their internal cavities to
  • NMR signals corresponding to Trp residues were shifted upon the addition of G1-β-CD due to encapsulation of the tryptophan residues in the G1-β-CD cavity [92]. In addition, the 1H NMR signals for cysteine 64 and isoleucine 98 were also influenced to a considerable extent with the addition of G1-β-CD
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Published 07 Dec 2016

Rearrangements of organic peroxides and related processes

  • Ivan A. Yaremenko,
  • Vera A. Vil’,
  • Dmitry V. Demchuk and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

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Published 03 Aug 2016

Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides

  • Andrew W. Truman

Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120

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  • streptococcal RiPP that is involved in bacterial communication [127]. Here, StrB catalyses the formation of a carbon–carbon bond between lysine and tryptophan side chains [25]. This is proposed to be mechanistically similar to thioether bond formation, although the role of the second [4Fe–4S] cluster is likely
  • to differ slightly as it is unlikely that either carbon initially bonds to this cluster (Figure 10B). Instead, a radical on the lysine β-carbon (generated by 5’-dA• hydrogen abstraction) attacks C-7 on the tryptophan ring. This generates an indolyl radical that can lose an electron to the second [4Fe
  • candidate enzymes. A number of these cyclisations are found in partially characterised pathways, such as the S–C cross-link in α-amanitin (Figure 8B) that is formed between cysteine and tryptophan residues (the tryptathionine linkage [131]). The ComQXPA quorum sensing (QS) system [132] found in Bacillus
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Published 20 Jun 2016

Conjugate addition–enantioselective protonation reactions

  • James P. Phelan and
  • Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

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  • the major enantiomer was not defined (Scheme 3) [18]. Indium was used to initiate the addition of a perfluorobutyl radical to α-aminoacrylate 11 followed by hydrogen atom transfer to the resulting α-amino α-ester radical from (R,R)-12. Enantioenriched tryptophan derivatives are useful building blocks
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Published 15 Jun 2016

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

  • Daniel Wiegmann,
  • Stefan Koppermann,
  • Marius Wirth,
  • Giuliana Niro,
  • Kristin Leyerer and
  • Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

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  • between F288 and glutamic acid 287 (E287) with the peptide motif arginine-tryptophan-x-x-tryptophan (RWxxW, x represents an arbitrary amino acid) was found. Mutants F288L and E287A showed reduced or no detectable enzyme inhibition, thus indicating a secondary binding site for potential MraY inhibitors
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Published 22 Apr 2016

Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

  • Gergely L. Tolnai,
  • Jonathan P. Brand and
  • Jerome Waser

Beilstein J. Org. Chem. 2016, 12, 745–749, doi:10.3762/bjoc.12.74

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  • is highly attractive, but the use of a carbon linker is usually required. Herein, we report the gold-catalyzed direct alkynylation of tryptophan in peptides using the hypervalent iodine reagent TIPS-EBX (1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one). The reaction proceeded in 50–78% yield
  • ][15][16][17], whereas the more challenging modification of the electron-rich aromatic residues of tyrosine [18][19][20] and tryptophan [21][22][23][24][25][26][27][28][29][30][31] has been the focus of recent interest. As tryptophan is a rare amino acid, its functionalization is especially interesting
  • wondered if this transformation could be extended to tryptophan-containing peptides. Even if the reaction gave C3-alkynylation for C3-unsubstituted indoles, we demonstrated that C2-alkynylation could be achieved on skatole (2a, Scheme 1B) [37]. Very recently, Hansen et al. indeed reported a modified
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Published 19 Apr 2016

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

  • Gabor Benkovics,
  • Ondrej Hodek,
  • Martina Havlikova,
  • Zuzana Bosakova,
  • Pavel Coufal,
  • Milo Malanga,
  • Eva Fenyvesi,
  • Andras Darcsi,
  • Szabolcs Beni and
  • Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

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  • -phenylalanine, N-(1-naphthyl)ethylenediamine, 4-nitroaniline, p-aminoacetophenone, tyramine) and nine in the form of anions (N-acetyl-DL-phenylalanine, N-acetyl-DL-tryptophan, N-benzoyl-DL-phenylalanine, N-boc-DL-tryptophan, N-FMOC-DL-valine, N-FMOC-DL-alanine, N-FMOC-DL-leucine, DL-3-phenyllactic acid, (R
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Published 19 Jan 2016

Recent highlights in biosynthesis research using stable isotopes

  • Jan Rinkel and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

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  • are widely used as antibiotics in fish farming industry. All compounds from this class feature a nine-membered dilactone core and a 3-formamidosalicylic acid moiety [84]. The latter provides an interesting biosynthetic rearrangement starting from tryptophan, which was investigated both by isotopic
  • labeling experiments and by using fluorine as a positional label of the aromatic structure [85]. The formamido-residue in antimycine A1 (79, R1 = R2 = H, Scheme 14) is located in the meta-position with respect to the carboxylic acid moiety, whereas in the precursor molecule 76, derived from tryptophan (75
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Published 09 Dec 2015

Synthesis of constrained analogues of tryptophan

  • Elisabetta Rossi,
  • Valentina Pirovano,
  • Marco Negrato,
  • Giorgio Abbiati and
  • Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

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  • library of compounds bearing the free amino acid function at C-3 and pertaining to the class of constrained tryptophan analogues. Keywords: constrained tryptophans; Diels–Alder; indoles; tetrahydrocarbazoles; unnatural amino acids; Introduction With the term of “unnatural” amino acids, a plethora of
  • six-membered ring [8]. Moreover, fused bicyclic unnatural amino acids are present in the structures of two antiviral drugs, boceprevir (Merck) [9] and telaprevir (Vertex, Johnson & Johnson) [10] used against hepatitis C genotype 1 viral infections (Figure 1). In this research field, tryptophan
  • analogues received less attention with respect to others congeners. Constraints and modifications in the tryptophan core have been mainly attained following two different strategies: embodying the nitrogen atom of the amino acid function in a β-carboline framework or inserting a linking group between the α
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Published 27 Oct 2015

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

  • Louis P. Sandjo,
  • Victor Kuete and
  • Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

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  • studies performed on this topic. Riddick showed the oxidation product of tryptophan (61) (kynurenine (62)) as the precursor for the biosynthesis of pyridoacridines (Figure 6) [74]. Kynurenine (62) with acetic acid forms the quinolinone 63, which in presence of amino acids such as cysteine, asparagine
  • tryptophan (61a) and dopamine (66) performed by Steffan et al. established these two chemical entities as precursors of shermilamine B (67), a secondary metabolite produced by tunicates. Consequently, the authors postulated that tryptophan was transformed into kynurenine (62), which was in turn
  • tryptophan and dopamine as precursors of pyridoacridines. Thus, formaldehyde and amino acids are responsible for the thiazole, piperidone, oxathiolane and thiomorpholinone rings found in pyridoacridines structures. Biological activity The biological activity of pyridoacridines, including both natural and
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Published 18 Sep 2015

Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

  • Mohamed Yacine Ameur Messaoud,
  • Ghenia Bentabed-Ababsa,
  • Madani Hedidi,
  • Aïcha Derdour,
  • Floris Chevallier,
  • Yury S. Halauko,
  • Oleg A. Ivashkevich,
  • Vadim E. Matulis,
  • Laurent Picot,
  • Valérie Thiéry,
  • Thierry Roisnel,
  • Vincent Dorcet and
  • Florence Mongin

Beilstein J. Org. Chem. 2015, 11, 1475–1485, doi:10.3762/bjoc.11.160

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  • , as well as in pharmaceuticals (e.g., pyrrolnitrin, zomepirac) and polymers (e.g., photovoltaic cells). Indole is similarly present in numerous natural products (e.g., tryptophan, melanin, bufotenin, psilocin, indican) including bioactive products (e.g., strychnine, brucine, yohimbine, reserpine
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Published 24 Aug 2015

Azobenzene-based inhibitors of human carbonic anhydrase II

  • Leander Simon Runtsch,
  • David Michael Barber,
  • Peter Mayer,
  • Michael Groll,
  • Dirk Trauner and
  • Johannes Broichhagen

Beilstein J. Org. Chem. 2015, 11, 1129–1135, doi:10.3762/bjoc.11.127

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  • dansyl competition assay is employed for this purpose [1][14]. However, as this assay is fluorescence-based and azobenzenes can quench fluorescence [15], this might cause a distortion in the obtained data. Furthermore, irradiation with UV light (i.e., λ = 280 nm for tryptophan excitation) can result in
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Published 07 Jul 2015
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Published 08 Apr 2015

Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

  • Michele Mari,
  • Simone Lucarini,
  • Francesca Bartoccini,
  • Giovanni Piersanti and
  • Gilberto Spadoni

Beilstein J. Org. Chem. 2014, 10, 1991–1998, doi:10.3762/bjoc.10.207

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  • alkylation; indoles; migration; tryptophans; Introduction Facile access to tryptophan and unnatural tryptophan derivatives is of general interest because tryptophans are found in many naturally occurring compounds and are an important component of biologically active compounds [1][2][3][4][5][6][7
  • ]. Tryptophan and tryptophan analogs also have applications in chemical biology thanks to the highly environment-sensitive fluorescence properties of the indole ring [8][9][10][11][12][13][14][15][16][17] and when incorporated into peptides, they lead to compounds with increased resistance to enzymatic
  • (also known as pyrroloindolines), and tryptophan-containing natural products from simple indole starting materials [38][39][40][41][42][43][44]. In 2010, we reported a novel one-pot approach for the preparation of pyrroloindolines 4 by a cascade addition/cyclization strategy between simple alkyl C3
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Published 26 Aug 2014

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

  • Fabrizio Chiodo,
  • Marco Marradi,
  • Javier Calvo,
  • Eloisa Yuste and
  • Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

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  • tryptophan). An Acquity UPLC coupled to LCT Premier XE mass spectrometer (Waters, Mildford, MA) was employed for the drug quantification. The chromatographic separations were performed on a 100 × 2.1 mm Acquity BEH 1.7 µm C18 column (Waters, Mildford, MA). The gradient elution buffers were A (water and 0.1
  • samples were spiked with 10 µL of the appropriate internal standard solution before the LC–MS analysis (tryptophan and cytidine at 1 µM were used for quantification of 3TC and ABC, respectively). Calibration curves were designed over the range of 1–200 nM in triplicate. All the standard solutions were
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Published 12 Jun 2014
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