Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• affect its pharmacological properties and metallophoric potential against copper(II) when compared to the unsubstituted counterpart. Nevertheless, the bioinspired compound was still able to reduce oxidative stress and affect the aggregation of the amyloid-β peptide, related to pathophysiological events

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• ability of the products. Up to >80% inhibition of the amyloid-β peptide aggregates were achieved with these compounds, with the highest activity found for the 4-N-methylpiperidyl derivative. Ethers The synthesis of the bis(indol-6-yl) ether 175 was performed by Chai in 2017. Their protocol used a Cu(OAc)2

Stereoselective synthesis of perillaldehyde-based chiral β-amino acid derivatives through conjugate addition of lithium amides

• Zsolt Szakonyi,
• Reijo Sillanpää and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2014, 10, 2738–2742, doi:10.3762/bjoc.10.289

• proved to be versatile building blocks both in pharmacological developments and asymmetric syntheses [1][2][3][4][5][6][7][8]. Alicyclic and bicyclic chiral β-amino acids have played a key role in the synthesis of β-peptide-type foldamers, where through the selection of an appropriate alicyclic or

• incorporated in a β-peptide sequence will be able to force the formation of unique β-helix or β-sheet structures, thereby affording a novel route to promising β-peptides. Structure of 10D and an ORTEP plot of its configuration. Reagents and conditions: (i) 2-methyl-2-butene, t-BuOH, NaClO2 (aq), NaH2PO4 (aq

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• preparation of condensed O,N-heterocycles with the 1,2,8,9-tetrahydro-7bH-quinolino[1,2-d][1,4]benzoxazepine skeleton, the neuroprotective activities of which were tested against hydrogen peroxide (H2O2), Alzheimer's amyloid β-peptide fragment Aβ25–35 and oxygen–glucose deprivation (OGD)-induced neurotoxicity

Molecular architecture with carbohydrate functionalized β-peptides adopting 3₁₄-helical conformation

• Nitin J. Pawar,
• Navdeep S. Sidhu,
• George M. Sheldrick,
• Dilip D. Dhavale and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2014, 10, 948–955, doi:10.3762/bjoc.10.93

• cooperative effects. To evaluate carbohydrate interaction and recognition, the structurally defined attachment of sugar units to a rigid template is highly desired. β-Peptide helices offer conformationally stable templates for the linear presentation of sugar units in defined distances. The synthesis and β

• -peptide incorporation of sugar-β-amino acids are described providing the saccharide units as amino acid side chain. The respective sugar-β-amino acids are accessible by Michael addition of ammonia to sugar units derivatized as α,β-unsaturated esters. Three sugar units were incorporated in β-peptide

• oligomers varying the sugar (glucose, galactose, xylose) and sugar protecting groups. The influence of sugar units and the configuration of sugar-β-amino acids on β-peptide secondary structure were investigated by CD spectroscopy. Keywords: carbohydrate recognition; conformation; glycopeptide; β-peptide

Synthesis of trifunctional cyclo-β-tripeptide templates

• Frank Stein,
• Tahir Mehmood,
• Tilman Plass,
• Javid H. Zaidi and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2012, 8, 1576–1583, doi:10.3762/bjoc.8.180

• protection of the primary α-amino group. Therefore, tert-butyloxycarbonyl (Boc) protection was used to mask all α-amino groups during solid-phase synthesis of the tripeptide. Synthesis of the cyclo-β-peptide scaffold The Boc protected β-amino acid building blocks for SPPS of the cyclic β-tripeptide were

• (5) and the nucleobase moieties thymine-1-yl acetic acid (6) and (N4-benzyloxycarbonyl)cytosine-1-yl acetic acid (7) were attached to the cyclo-β-peptide yielding monofunctionalized templates 14, 10 and 12 (Figure 4). The second amino group was Fmoc-deprotected with 20% piperidine in DMF. Coupling of

• the fully protected cell-penetrating peptide penetratin 8 [26] with the homolysine side chain of the cyclic β-tripeptide 15 was accomplished by HOBt and HBTU activation in solution using a 10-fold access of penetratin. The β-peptide template 16 functionalized at two side chains was obtained, purified

The C–F bond as a conformational tool in organic and biological chemistry

• Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

• case of β-peptide 66, the fluorine atom aligns antiparallel to the adjacent C=O bond and gauche to the adjacent amide nitrogen, and this reinforces the helical conformation of the β-peptide. In contrast, the helical conformation of β-peptide 67 cannot accommodate these favourable alignments, so in this