Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis

• Zhiyong Yin and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67

• ) allowed for test incubations with unlabelled glutamic acid in the presence of the cofactor pyridoxal phosphate (PLP), showing the complete conversion of glutamic acid (3) into γ-aminobutyric acid (4) (Scheme 2). The crude product was used without purification for a Schotten–Baumann esterification with

• benzyl alcohol to obtain the unlabelled ester 5 with a quantitative yield over two steps. After having established this method, (5-13C)glutamic acid (3) was converted analogously into (1-13C)-5, unfortunately with a little lower, but still very good yield of 83%. By employing Yamaguchi conditions, the

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• at the α-position have not yet been studied. Typically, two primary strategies are employed to build an N-heterocycle-glutarimide diad. The first involves assembling a heterocyclic fragment utilizing glutamic acid imide (2, Scheme 1, route A), while the second involves alkylating NH-heterocycle with

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• ) and 1H,13C total correlation spectroscopy (HSQC-TOCSY), the individual spin systems within each amino acid residue were fully established. Subsequently, seven amino acid residues were identified as glutamic acid, valine-1, aspartic acid, leucine-1, valine-2, leucine-2 and valine-3, see Table 1 and

• , analysis of the LC–HRESIMSn showed the presence of several b and y sequence tag ions indicating fragmentations from the middle of the cyclic peptide and most importantly the specific positions of each amino acid residue (Figure 4). Due to the presence of the free hydroxy groups of aspartic and glutamic

• acid and the elaborate system of aliphatic side chains, the sequence tag ions generated by systematic loss of amino acids were each subjected to several facile losses of H2O, –CH3, –C2H2O and CO resulting in the generation of several peaks in the LC–HRESIMSn spectrum. The b and y ion fragmentation

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• successfully obtain a given polymorph. The work of Myerson and co-workers demonstrates this by examining polymorph dynamics to achieve a successful crystallization of ʟ-glutamic acid using a continuous mixed suspension mixed product removal crystallization (MSMPR) approach [113]. Recently, a kinetically

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• ) and GCP (green beads) groups are found near the aspartic (ASP) and glutamic acid (GLU) residues of 14-3-3ζ. In the presence of the peptides, at least one Lys or GCP group is found near the phosphorylated serine (SER) group (magnified image in (d)) of the C-Raf peptides. In this figure, all the

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• additional ethylene unit in the linker suggested a conformation with the highest similarity to the linear reference peptide P6 (see Supporting Information File 1), thus representing a good compromise between rigidity and preservation of the target secondary structure. Serine in i-position and glutamic acid

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• employing a variety of amino esters and a wide range of (hetero)aromatic and alkyl ketones. Natural products, such as 5α-cholestan-3-one and dihydrotestosterone, were also tolerated, affording a new strategy to modify biologically active compounds. Amino acids, such as tyrosine, ʟ-Phe-ʟ-Phe, glutamic acid

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• . Starting imine 135 with two well-defined stereogenic centers at the hydrocarbon backbone were prepared as a mixture of (RS)- and (SS)-diastereoisomers from ᴅ-glutamic acid. After nucleophilic addition to the imine, a successive cyclization–desulfinylation occurred to give the corresponding piperidinone

Menthyl esterification allows chiral resolution for the synthesis of artificial glutamate analogs

• Kenji Morokuma,
• Shuntaro Tsukamoto,
• Kyosuke Mori,
• Kei Miyako,
• Ryuichi Sakai,
• Raku Irie and
• Masato Oikawa

Beilstein J. Org. Chem. 2021, 17, 540–550, doi:10.3762/bjoc.17.48

• interesting that the (2R)-isomer is neuronally active because the (2S)-isomer is generally neuroactive for glutamic acid and some natural products with a glutamate motif, dysiherbaine [27] and kainic acid [28]. Since the (2R)-isomer is the neuronally active enantiomer in these analogs (Figure 1), our future

Synthetic strategies of phosphonodepsipeptides

• Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

• , another library of phosphonodepsipeptides 78 was prepared (Scheme 12) [27]. Synthesis of γ-phosphonodepsipeptides γ-Phosphonodepsipeptides 79 have been prepared from N-Cbz-ʟ-glutamic acid (80) and diethyl 2-hydroxyglutarate (84). To prepare phosphorus analogues of γ-glutamyl peptide, the starting N-Cbz-ʟ

• -glutamic acid (80) was first transformed to the corresponding dimethyl phosphonate 81. After aminolysis and chlorination the corresponding phosphonochloridate 83 was obtained. The latter was further reacted with diethyl 2-hydroxyglutarate (84), affording γ-phosphonodepsidipeptide 79 in only 6.7% yield

• (Scheme 26) [39]. Synthesis of γ-phosphonodepsipeptides To prepare phosphorus analogues of γ-glutamyl peptide, N-Cbz-ʟ-glutamic acid (80) was initially converted to the corresponding dimethyl phosphonate 81 and further to the methyl phosphonic monoester 82. The ester 82 was then coupled with diethyl 2

Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils

• Jan-Erik Ostwaldt,
• Christoph Hirschhäuser,
• Stefan K. Maier,
• Carsten Schmuck and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11

• with TFA yielded the bis-GCP derivate 1 in 40% yield over two steps. Accordingly, the ACP derivative 6 was coupled with BINAM, followed by deprotection to give bis-ACP derivative 2 (60% yield over two steps). For the extension of the linker unit, BINAM was first coupled with glutamic acid (O-benzyl and

• performed structural modifications in order to increase the solubility. Keeping the BINAM backbone and the ACP binding unit, we performed two modifications (as described above, see Figure 2b): First, the linker unit was extended by insertion of a benzyl-protected glutamic acid between the BINAM core and the

• supramolecular ring–chain polymerization. a) GCP and ACP motif, as charged and neutral BUs and BINAM as precoordinating LU. b) Compounds 1, 2, 3 and 4 are based on the combination of BINAM with the GCP or ACP motif, respectively. Synthesis of compounds 1 to 4. Reagents and conditions: i) ʟ-Boc-glutamic acid

Circularly polarized luminescent systems fabricated by Tröger's base derivatives through two different strategies

• Cheng Qian,
• Yuan Chen,
• Qian Zhao,
• Ming Cheng,
• Chen Lin,
• Juli Jiang and
• Leyong Wang

Beilstein J. Org. Chem. 2021, 17, 52–57, doi:10.3762/bjoc.17.6

• luminescence with glum values of +0.0021, and −0.0025, respectively. The second way to fabricate the rac-TBPP-based CPL-active material is to co-gel the fluorescent rac-TBPP with a chiral ᴅ-glutamic acid gelator DGG by co-assembly strategy. At the molar ratio of rac-TBPP/DGG = 1:80, the glum value of the co

• -active enantiomers R2N-TBPP and S2N-TBPP, respectively. The other stratgy is to co-assemble the fluorescent rac-TBPP with the chiral ᴅ-glutamic acid gelator DGG to form the CPL-active co-gel. Interestingly, adjusting the stoichiometric ratios of rac-TBPP/DGG of the co-assembling system, the handedness of

• DGG. In the CPL-active co-gels, noncovalent weak interactions might be formed between achiral fluorophores and a chiral gelator. So, the CPL emission of co-gels could be adjusted easily by external stimuli. The ᴅ-glutamic acid gelator DGG and its enantiomer LGG possess three hydrogen-bond sites, two

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• serum albumin. Other biomolecules such as adenosine, adenosine monophosphate, adenosine triphosphate, phosphate, pyrophosphate, glucose, heparin, hyaluronic acid and chondroitin sulfate, and amino acids containing two carboxylates (glutamic acid and aspartic acid) have not increased the fluorescence

• biological analytes including such as adenosine, adenosine monophosphate (AMP), adenosine triphosphates (ATP), phosphate (Pi), pyrophosphate (PPi), ct-DNA, glucose, bovine serum albumin (BSA), glutamic acid and aspartic acid. They are also selective over the similar biological analytes hyaluronic acid or

GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis

• Toan K. Phung,
• Cassandra L. Pegg and
• Benjamin L. Schulz

Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180

• cysteines was set as a fixed modification, and dynamic modifications included deamidation of asparagine, monooxidised methionine, and the formation of pyroglutamate at N-terminal glutamic acid and glutamine. All variable modifications were set as “Common 1” allowing each modification to be present once on a

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• in mind, we synthesized an octapeptide, PEP-1, which contains two valine (Val) units and one leucine (Leu) unit as the hydrophobic residues and one glutamic acid (Glu) residue, two arginine (Arg) units, and one cysteine (Cys) substituent as polar moieties (Scheme 1). This choice of amino acids

A dynamic combinatorial library for biomimetic recognition of dipeptides in water

• Florian Klepel and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2020, 16, 1588–1595, doi:10.3762/bjoc.16.131

• cleaved (see Supporting Information File 1 for details). It also enables easy incorporation of nonnatural amino acids if desired [21]. We prepared a DCL by dissolving CFC, CEC, CSC and CAC (C for cysteine, F for phenylalanine, E for glutamic acid, S for serine, A for alanine) in an equimolar ratio in a

Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals

• Adam Drop,
• Hubert Wojtasek and
• Bożena Frąckowiak-Wojtasek

Beilstein J. Org. Chem. 2020, 16, 616–620, doi:10.3762/bjoc.16.57

• ensure the required configuration of the asymmetric centers determining the biological activity of this compound. They include the use of naturally occurring chiral substrates, such as ʟ-glutamic acid [13], ʟ-tartaric acid [14][15][16], ᴅ-glucose [17], and sorbitol [18] as starting materials, as well as

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• ,1''R)-146. After treatment with acetic acid and ester hydrolysis the intermediary amino alcohol (2R,3S,4S)-147 was oxidized and hydrogenolytic removal of benzyl groups completed the synthesis. The orthogonally protected 3-hydroxy-ʟ-glutamic acid (2S,3R)-148 was obtained from the aziridine ester (2R

Selectivity in multiple multicomponent reactions: types and synthetic applications

• Ouldouz Ghashghaei,
• Francesca Seghetti and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2019, 15, 521–534, doi:10.3762/bjoc.15.46

• involving terephthalaldehyde; C) Multiple GBB processes with diaminodiazines. Biased substrates for selective MMCRs. The Union concept. A) Asinger–Ugi combination; B) Passerini–Ugi/azide from anthranilic acid; C) Passerini–Ugi multiple MCR from glutamic acid. Relevant examples of consecutive MCRs exploiting

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• Dorota G. Piotrowska Iwona E. Glowacka Andrzej E. Wroblewski Liwia Lubowiecka Bioorganic Chemistry Laboratory, Faculty of Pharmacy, Medical University of Lodz, Muszynskiego 1, 90-151 Lodz, Poland 10.3762/bjoc.15.22 Abstract Glutamic acid is involved in several cellular processes though its role

• as the neurotransmitter is best recognized. For detailed studies of interactions with receptors a number of structural analogues of glutamic acid are required to map their active sides. This review article summarizes syntheses of nonracemic hydroxyglutamic acid analogues equipped with functional

• pool; glutamate analogues; Introduction L-Glutamic acid (1, Figure 1) plays an important role in the biosynthesis of purine and pyrimidine nucleobases [1]. It also takes part in metabolic transformation to L-glutamine by L-glutamate synthetase (GS) which is crucial for cell maintenance. In neoplastic

Computational characterization of enzyme-bound thiamin diphosphate reveals a surprisingly stable tricyclic state: implications for catalysis

• Ferran Planas,
• Michael J. McLeish and
• Fahmi Himo

Beilstein J. Org. Chem. 2019, 15, 145–159, doi:10.3762/bjoc.15.15

• + state. With only one known exception [7], the protonation/deprotonation of the N1′ position is performed by a highly conserved glutamic acid residue that is thought to stabilize the imino tautomer IP [6]. The subsequent loss of a proton from N4′ of APH+ gives the IP state. Deprotonation of the C2

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• movement of the catalyst with shorter spacer within the channel seems advantageous for the turnover. Additionally, a few potentially coordinating residues (glutamic acid and tyrosine) are further away from the active site when the shorter spacer is utilized [60]. Structural expansions of β-barrel proteins

Novel solid-phase strategy for the synthesis of ligand-targeted fluorescent-labelled chelating peptide conjugates as a theranostic tool for cancer

• Sagnik Sengupta,
• Mena Asha Krishnan,
• Premansh Dudhe,
• Ramesh B. Reddy,
• Bishnubasu Giri,
• Sudeshna Chattopadhyay and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2018, 14, 2665–2679, doi:10.3762/bjoc.14.244

• modified by removal of the L-glutamic acid residue to give the pteroic acid moiety (Figure 2). The binding affinity of the modified folate is relatively weaker than folic acid [41]. The targeting ligand, pteroic acid, is covalently coupled to 8-aminocaprylic acid to separate the active binding site of

• tris(tert-butoxy) protected DUPA ligand 4. Reagents and conditions: (a) Triphosgene, triethylamine, dichloromethane (DCM), −50 °C to rt; (b) L-glutamic acid γ-benzyl-α-tert-butylester hydrochloride, triethylamine, DCM, rt, overnight; (c) H2, Pd/C, CH2Cl2, 24 h, rt. Attempted synthesis of PSMA targeted