Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• tetrahydropyridazine scaffold is also found in numerous natural linear or cyclic peptides such as svetamycins or antrimycins as dehydropiperazic acid (Figure 2) [10]. Whereas many publications have been devoted to the synthesis and structure of piperazic acid derivatives (dehydro, chloro, hydroxy, …) [11][12], nothing

• feature results will be further confirmed by the insertion of these cyclic β-dehydropiperazic acids in longer peptide sequences. Examples of bioactive tetrahydropyridazine derivatives. Linear and cyclic peptides incorporating the dehydropiperazic acid moiety. Piperazic acid and analogues and target

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• resulting peptides exhibit unique structural features due to thioether bridges between dehydrated serine or threonine (Dha/Dhb) and cysteine (Cys). These thioether bridges lead to cyclic peptides with the modified amino acid lanthionine (Dha-Cys) or methyllanthionine (Dhb-Cys). The strong antimicrobial

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• chair) produced more than 20. Analysis of the predicted core sequence seemed to suggest moroidin-like molecules (Figure 3), but no cyclic peptides have been isolated from any member of this family. Unfortunately, sourcing members of this small family proved challenging and we were unable to evaluate

• burpitide natural products from plants. Phylogenetic visualization of the potential precursor peptides validated families known to make these cyclic peptides, but also suggested new producers. Finally, metabolomic analyses supported the predicted new sources of burpitides, aiding in our understanding of the

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• several positions and also form 6–14 residue cyclic peptides [37][38]. It should be noted that TycC TE was more sensitive to the amino acid changes near the site of ring closure. The alkyne-containing analogs were conjugated to a variety of azido sugars via copper(I)-catalyzed cycloaddition to obtain the

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• heptapeptides isolated predominantly from Aspergillus sp. [1][2][3][4][5][6][7][8]. Distinctive features of these cyclic peptides include the non-proteinogenic amino acid γ-aminobutyric acid (GABA) and the incorporation of up to five ᴅ-amino acids (Figure 1) [1][2][3][4][5][6][7][8]. The amino acids at

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• ., vitamin B12, chlorophyll, metalloproteins, cyclic peptides, etc). PAMs themselves and their metal complexes exhibit various useful properties [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], particularly, they possess a wide range of biological activities and are used as contrast

Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• chemical communication. The retrosynthesis of peptide 1 is displayed in Scheme 1. First, the cyclic peptide 1 was linearized by retrosynthesis, and acid-labile protecting groups were attached onto the reactive side chain. The biomimetic synthesis of cyclic peptides often enables efficient synthesis [12][13

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• . For example, consider a pair of molecules (Figure 1) that selectively inhibit the Gq11-signaling pathway in cells [15][16]. The molecules are complex cyclic peptides, and the construction of analogs of the molecules to probe the basis of their activity is a significant challenge. In an ideal situation

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

• –Miyaura cross-coupling; Introduction Peptide cyclisation emerged as a popular approach to limit conformational mobility in order to enhance the binding affinity towards a biological target. Moreover, cyclic peptides are more stable against proteolytic digestion and can provide an improved membrane

• peptide macrocyclisation of the two above mentioned side chain residues of the natural amino acids. However, these Pd-mediated stapling reactions were performed only on an analytical scale and the secondary structures of the cyclic peptides were not studied. Since tryptophan has only an incidence of about

• data [72]. Moreover, the epimerization by the conditions of SMC is unlikely as it has been excluded by total hydrolysis of a late-stage SMC modified RGD peptide [67]. Analysis of the secondary structures of the cyclic peptides P2–P4 by CD spectroscopy also did not show a significantly increased α

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• highly complex peptides. Cyclic peptides are known to be structurally and chemically stable against enzymatic degradation because the cyclic skeleton restricts the conformation and limits β-turns. In this manganese catalysis, the late-stage C–H allylation manifold was extended to the construction of a

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

Enzyme-instructed morphological transition of the supramolecular assemblies of branched peptides

• Dongsik Yang,
• Hongjian He and
• Bing Xu

Beilstein J. Org. Chem. 2020, 16, 2709–2718, doi:10.3762/bjoc.16.221

• utilizes nonlinear peptides. For example, nonribosomal peptides exist in other geometries, such as branched (e.g., bleomycin) or cyclic peptides (e.g., vancomycin) [31]. While the understanding of the synthesis of branched peptides is well-developed, the self-assembly and enzymatic conversion of branched

Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

• Rémi Martinent,
• Javier López-Andarias,
• Dimitri Moreau,
• Yangyang Cheng,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

• and cyclic peptides with Schmuck cations for gene transfection. Evolution from CPPs to CPDs and COCs. Structure of a) the trifunctional transporter 23 and c) the HaloTag reporter 26. b) Schematic mechanism of the thiol-mediated uptake of COCs with dynamic covalent disulfide exchange with exofacial

• attached to the tweezers are used to facilitate endosomal escape. These results indicate that the balance between the number of GCP, the binding affinity, and the buffering capacity of Schmuck peptides plays a key role in the gene transfection process. In 2016, the Schmuck group developed the first cyclic

• peptides that can be used as gene transfection vectors [36]. Unlike linear Schmuck peptides, the cyclic peptide 16 can self-assemble into nanofibers due to the binding between the GCP moiety and the backbone of an adjacent peptide. This binding interaction could stabilize the stacking of peptides by

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis

• David C. B. Siebert,
• Roman Sommer,
• Domen Pogorevc,
• Michael Hoffmann,
• Silke C. Wenzel,
• Rolf Müller and
• Alexander Titz

Beilstein J. Org. Chem. 2019, 15, 2922–2929, doi:10.3762/bjoc.15.286

• resistances in clinically used bacterial targets, innovative antiinfective strategies comprising new antibiotic classes and virulence-attenuating compounds have been developed [3][4]. The argyrins 1–8 are a family of 8 naturally occurring cyclic peptides isolated by Sasse, Höfle and co-workers from the

• myxobacterium Archangium gephyra (Figure 1) [5][6]. These cyclic peptides have interesting biological activities such as cytotoxic activity presumably via proteasome inhibition and immunomodulatory effects, and they also show good antibiotic effects against P. aeruginosa [7][8][9]. The structure–activity

• relationship for the natural argyrins A–H revealed argyrin B as most potent derivative (2, IC50 0.08 µg/mL). In 1996, two cyclic peptides with a similar sequence but a proposed regioisomer of the methoxytryptophan were reported as antibiotics A21459A and B [7][10]. Later, it was shown that A21459A and B are

Synthesis of novel sulfide-based cyclic peptidomimetic analogues to solonamides

• José Brango-Vanegas,
• Luan A. Martinho,
• Lucinda J. Bessa,
• Andreanne G. Vasconcelos,
• Alexandra Plácido,
• Alex L. Pereira,
• José R. S. A. Leite and
• Angelo H. L. Machado

Beilstein J. Org. Chem. 2019, 15, 2544–2551, doi:10.3762/bjoc.15.247

• ), as expected for the C-terminal carboxamide, we observed three ions derived from the breaking of two amide bonds, starting from the opening of the macrocycle by the loss of one, two or three amino acid residues as neutral fragments. This fragmentation pattern agrees with the one expected for cyclic

• peptides [40]. Noteworthy, the detected ions A–C always showed the –SCH2CH=NH moiety, confirming the formation of the sulfide group (Schemes S4–S11, Supporting Information File 1). The NMR experiments also confirmed the macrocyclic structure (Supporting Information File 1). The 1H NMR spectra of compounds

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

• Sachin S. Burade,
• Sushil V. Pawar,
• Tanmoy Saha,
• Navanath Kumbhar,
• Amol S. Kotmale,
• Manzoor Ahmad,
• Pinaki Talukdar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

• peptides from C-3 fluorinated ᴅ-glucofuranoid amino acids and demonstrated their selective anion transport activity [17][18]. In continuation of our interest in sugar-derived cyclic peptides [19], we aimed to synthesize cyclic peptides I and II from the corresponding linear di- and tetrapeptides, however

• converted to amino acid di- and tetrapeptides 8 and 9, respectively, using hydrolysis followed by a hydrogenation reaction protocol (Scheme 2). In order to get cyclic peptides I and II (Figure 1), an individual intramolecular coupling reaction of linear dipeptide 8 and tetrapeptide 9 was attempted. Thus

• different types of cyclic peptides as anion transporters. Gale, Luis, and co-workers [41] have separately reported the linear pseudopeptides as receptors and transporters of chloride and nitrate anions. Inspired by our recent ion transport studies with fluorinated acyclic and cyclic sugar derived peptides

Solid-phase synthesis of biaryl bicyclic peptides containing a 3-aryltyrosine or a 4-arylphenylalanine moiety

• Iteng Ng-Choi,
• Àngel Oliveras,
• Lidia Feliu and
• Marta Planas

Beilstein J. Org. Chem. 2019, 15, 761–768, doi:10.3762/bjoc.15.72

• amino acids [11]. Cyclic peptides containing biaryl linkages constitute attractive targets. On the one hand, a wide range of biaryl natural products have been reported to display interesting biological properties, such as biphenomycins, arylomycins and glycopeptide antibiotics [4]. On the other hand

• positively charged groups. Due to these structural properties, biaryl cyclic peptides have a great potential to meet the ever-increasing expectations of new drugs. However, their synthesis is viewed as very challenging. The formation of biaryl bonds in peptides has been performed through a Suzuki–Miyaura

• cross-coupling reaction [15][16][17][18][19] or via a Pd-catalyzed C–H activation reaction [20][21]. We have used the former reaction for the solid-phase preparation of biaryl cyclic peptides bearing a Phe-Phe, a Phe-Tyr or a Tyr-Tyr linkage [22][23]. Our approach involved the synthesis of the linear

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• peptides for their ability to disrupt PPIs in the β-sliding clamp of Staphylococcus aureus. In this elegant study, from a library of 900,000 cyclic peptides, which was intracellularly generated using the split-intein circular ligation of peptides and proteins (SICLOPPS) technology [66], three hits

Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• analysis of the cyclic ketones muscone and civetone [1]. Other classical examples are cyclic peptides such as valinomycin and cyclic oligosaccharides like cyclodextrins [2][3][4]. The literature has been recently reviewed [5]. Also, oligonucleotides form cyclic structures commonly existing in plasmid DNA

• and deprotection steps are necessary to control the cyclization process. Preorganization of the molecules can help to make cyclization more efficient. Azide–alkyne "click" chemistry has been executed to generate cyclic peptides [11][12][13], cyclic oligonucleotides [14][15][16][17] and other

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• the Ru complex and the cyclic peptides by the calixarene should be an advantage by preventing any negative effect of the RGD peptidic units on the photochemistry of the complex and, alternatively, prevents any influence of the complex on the affinity of the RGD patterns to interact with the targeted

• BIOVIA© software and geometry-optimized using the CHARMM force-field, taking into account previous molecular modelling simulations on cyclic peptides [83]. The structures were linked together yielding through several steps of energy minimizations, maintaining the ruthenium complex constrained in

Recyclable hypervalent-iodine-mediated solid-phase peptide synthesis and cyclic peptide synthesis

• Dan Liu,
• Ya-Li Guo,
• Jin Qu and
• Chi Zhang

Beilstein J. Org. Chem. 2018, 14, 1112–1119, doi:10.3762/bjoc.14.97

• . Compound 6 was subsequently oxidized with NaOCl/HCl to obtain FPID in 90% yield. Cyclic peptides, an important kind of peptides, possess several favorable properties such as target selectivity, good binding affinity and low toxicity, which make them attractive candidates in the development of therapeutics

• [43][44]. Due to the particular significance of cyclic peptides, chemists pay considerable attention to the efficient synthesis of cyclic peptides [45]. In the second part of the investigation of the synthetic utility of the FPID/(4-MeOC6H4)3P system, we tested this system in the cyclic peptide

• synthesis. The roots of Pseudostellaria heterophylla are well-known traditional Chinese medicine, which are often used as a lung and spleen tonic. There are more than 10 cyclic peptides isolated from it, for example, pseudostellarin A–H and heterophyllin A–D [37][46][47][48][49]. Cyclo(Gly-Gly-Tyr-Pro-Leu

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• fast renal clearance or low binding selectivity/affinity due to the unstable structure of the linear peptides, cyclic peptides have been introduced. An immense number of cyclic peptides have been synthesized [35][36][37] and many of them have displayed superior affinity and selectivity for the receptor

• than their parent linear counterparts [38]. Cyclic peptides are usually synthesized by reacting the N-terminus with the C-terminus or by exploiting specific functional groups of certain amino acids present in the sequence. A representative example is the sulfhydryl group of cysteine-containing peptides

• which may cyclize through the formation of intramolecular disulfide bonds [39]. The most commonly used linear peptides and cyclic peptides that can be delivered inside cancer cells via endocytosis and one that smuggles into glioma tissues via transcytosis (angiopep-2) are presented below: Arginine

Development of novel cyclic NGR peptide–daunomycin conjugates with dual targeting property

• Andrea Angelo Pierluigi Tripodi,
• Szilárd Tóth,
• Kata Nóra Enyedi,
• Gitta Schlosser,
• Gergely Szakács and
• Gábor Mező

Beilstein J. Org. Chem. 2018, 14, 911–918, doi:10.3762/bjoc.14.78

• cyclic NGR peptide–Dau bioconjugates including chemostability, lysosomal degradation, cellular uptake studies and in vitro cytostatic/cytotoxic effect. Results and Discussion Synthesis of cyclic NGR–Dau conjugates The NGR cyclic peptides were prepared as shown in Figure 1. All derivatives were