Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• derivative 2b further revealed that it adopts a favorable herringbone motif characterized by short π–π distances and extensive intermolecular hydrogen bonding. These structural features are anticipated to promote efficient charge transport. Future work will involve device fabrication and comparison of the

Introduction of a human- and keyboard-friendly N-glycan nomenclature

• Friedrich Altmann,
• Johannes Helm,
• Martin Pabst and
• Johannes Stadlmann

Beilstein J. Org. Chem. 2024, 20, 607–620, doi:10.3762/bjoc.20.53

• greatly facilitate keyboard-based mining for glycan substructures in glycan repositories. Keywords: N-glycans; nomenclature; structural features; Introduction Virtually any article on protein glycosylation starts with imposing assurances about the biological significance of the various structures. This

• -vertebrates contain numerous “unusual” and remarkable structural features such as methylation, sulfation, and zwitterionic non-sugar substituents, again glucuronic acid and often unusual architectures such as substituted core-fucose just as an example [44][52]. While the methylated moss glycans are accessible

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• , where conformation 1 corresponds to a 0 rotation, conformation 2 a 2π/3 rotation, and the conformation at the activation barrier top a π/3 rotation, respectively. To confirm the origin of the activation barrier that appears between conformation 1 and 2, we discuss the structural features of the

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• showed strong efficacy against commercially important weeds, in particular resistant ryegrass (LOLSS_R), combined with promising crop safety. In our view, these results underline that chemical innovation using isostere concepts and addressing unusual structural features is a useful tool to broaden the

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• rapid and comparatively easy deduction of structural features with the only requirement being the molecule's solubility in deuterated solvents. Therefore, NMR spectroscopy is of ubiquitous presence in many disciplines today. At the same time, with the high throughput analysis of samples that has been a

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• functions results principally from their unique physicochemical and structural features, including high negative charge, high viscosity and lubrication propensities, unbranched polysaccharide structures, low compressibility as well as the ability to attract and imbibe large amounts of water [17]. Unlike

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• proposed to identify the presence of structural features in oligosaccharides based on their gas-phase IR spectra [11]. To the best of our knowledge, machine learning classification studies have not been reported to identify saccharides using MS–IR carbohydrate analysis. Here, we report a study of a

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• caused by its structural features. NHCs constitute a well-established class of new ligands in organometallic chemistry. Although initially NHCs were regarded as pure σ-donor ligands, later experimental and theoretical studies established the presence of a significant back donation from the d-orbital of

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• ). These structural features enable the construction of a five-membered ring upon treatment with alkenes [9], diazo compounds (reaction g) [10], and nitriles [11]. Several approaches are available for the synthesis of cyclopropanedicarboxylates 1a, which consist of three steps: 1) conjugate addition, 2

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• , recently, we have reported a new class of FPDs, aroylpyrrolobenzothiazinetriones (APBTTs) 1 (Figure 2) [37][38], whose structural features allowed us to assume a possibility of the development of a new approach to PBTAs via a nucleophile-induced ring contraction in the 1,4-benzothiazine moiety of compounds

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• demonstrated thanks to the synthesis of analogues, which hardly superseded the natural product properties, highlighting the importance of the macrocycle and of the lactol ring for this biological activity (3 is inactive) [6][7]. Considering the structural features of these toxins and their valuable biological

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• innovative study of their crystal isostructurality within the series and with published complexes. SCXRD was employed to deduce structural features of the complexes at the molecular level, while the occurrence of severe guest disorder prompted the non-routine application of a method for yielding complex

• are isostructural, all of the salient structural features illustrated above and below for the γ-CD·PRO crystal are common to the γ-CD·BES crystal, which was not amenable to single crystal X-ray analysis. Solubility analysis Solubility determinations for the four native CD inclusion complexes (β-CD·BES

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• natural products have been popular synthetic targets mainly due to their intriguing structural features. For example, several total syntheses of 3–6 have been reported [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Previously, two synthetic studies of aberrarone

• . Impressed by the structural features and biological profiles, our group embarked a project on the total synthesis of this natural product. Herein, we report our stereoselective synthesis of its 6-5-5 tricyclic skeleton. Our retrosynthetic analysis is shown in Scheme 1. For the formation of the D ring with

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• , which somehow echoes with the last quote above, should be mentioned here: “There is a common misconception that “novel” compounds or concepts will lead to dramatically different structural features. It is unlikely that the drug of the future will be built from radically other structural classes than

• today’s drugs. […] the majority of the compounds will be built from the structural features known already today, yet they may occupy white areas on the map of chemical space”. The future will see if this statement is fully true but as explained above, active singletons in a chemical library appear to be

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• photophysical changes, have some common structural characteristics. For instance, heterocyclic units containing a nitrogen atom such as pyridine and thiazole, are one of the key structural features either in small molecules or polymers. Thus, the introduction of nitrogen with lone pairs of electrons in

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• from supramolecular protocols in catalysis [9]. Metal–ligand-based 2D and 3D self-assembled architectures have been extensively studied over the past decades [15][16][17][18][19][20][21]. While in the early years, the focus has been on the exploration of structural features, more recent advancements

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• structural features of these molecules. Amamistatin B (5) exhibits three bidentate ligand groups and can thus form an octahedral complex with ferric iron. The removal of one of these groups (e.g., the hydroxamate function at the ε terminus of the lysine residue) already leads to a considerable loss of iron

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• , increased accessibility and with structural features that may lead to different reactivities and/or selectivities that are still to be explored. The different electrochemical behaviour of DABCO may also lead to alternative photocatalysts for its activation, such as organic dyes that may not be suitable for

Strategies for the synthesis of brevipolides

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157

• -dihydro-α-pyrone derivatives, bearing either a distinctive cyclopropane or furan ring and named brevipolides A–O (1–15), have been isolated from the invasive plant Hyptis brevipes Poit. Their fascinating structural features, and the potent biological activities, including cytotoxicity against an array of

• immunodeficiency virus (HIV). The newly discovered brevipolides with interesting structural features in conjunction with promising biological activities have prompted the researchers to conduct synthetic studies. To date, there are six reported works in the literature for the syntheses of brevipolides, with the

• correlation with biological activity. This analysis attributed two detected [M − H]− signals to dihydrobrevipolides C and F. Nevertheless, further structural identification was not performed. Conclusion The characteristic structural features of 5,6-dihydro-α-pyrone derivatives isolated from Hyptis brevipes

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

• and diagnostics, and attempts to develop new PNA therapeutics. The discussion starts with a brief review of PNA’s binding modes and structural features, followed by the most impactful chemical modifications, PNA enabled assays and diagnostics, and discussion of the current state of development of PNA

• applications. We start with a brief review of PNA’s binding modes and structural features, continue to the most impactful chemical modifications, PNA enabled assays and diagnostics, and finish with discussion of the current state of development of PNA therapeutics. The common theme that emerges is that despite

• nucleobase stacking pattern similar to that of the A-form RNA [43]. Another crystal structure of a partially self-complementary PNA–PNA duplex revealed PNA’s ability to combine the P-form Watson–Crick duplex with higher order structural features, such as reversed Hoogsteen base pairing, interstrand

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• nuclease-resistant probes for studying RNA–protein interactions [70]. To better elucidate the structural features of 3'-NP DNA responsible for this enhanced selective binding and stability, the Egli group determined the crystal structure of the fully modified 3'-NP DNA duplex with the sequence 5'-d

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• [80]. Previous studies have shown that in the monomeric state the two helical domains of Myc display unstable structural features, similar to those of small IDPs, existing rather as a highly flexible pair of transient α-helices [81]. Based on this, Konrat and co-workers explored a combination of 19F

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• reports on the various synthetic efforts for both the formal and total synthesis of racemic and enantiopure inthomycins A–C (1–3). These compounds have three key structural features: an oxazole ring, a triene system, and an amide moiety with a chiral, hydroxylated carbon at the β-position. These

Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

• Dimas J. P. Lima,
• Antonio E. G. Santana,
• Michael A. Birkett and
• Ricardo S. Porto

Beilstein J. Org. Chem. 2021, 17, 28–41, doi:10.3762/bjoc.17.4

• ] (Figure 2). The small amount of these homotropane alkaloids isolated from ladybirds (e.g., for (−)-adaline, 35 mg from 800 specimens) emphasizes the desirability of practical syntheses for further biological studies [17]. Besides, the attractive structural features of (−)-adaline (1) and its relatives

Semiautomated glycoproteomics data analysis workflow for maximized glycopeptide identification and reliable quantification

• Steffen Lippold,
• Arnoud H. de Ru,
• Jan Nouta,
• Peter A. van Veelen,
• Magnus Palmblad,
• Manfred Wuhrer and
• Noortje de Haan

Beilstein J. Org. Chem. 2020, 16, 3038–3051, doi:10.3762/bjoc.16.253

• mannose, Hex/H, 162.0528 Da), N-Acetylhexosamines (N-acetylglucosamine or N-acetylgalactosamine, HexNAc/N, 203.0794 Da), fucose (Fuc/F, 145.0579 Da), and sialic acid (N-acetylneuraminic acid, NeuAc/S, 291.0954 Da). The combinatorial possibilities of these building blocks and the variety of structural

• features, such as the linkage position and anomeric configuration, make protein glycosylation a highly complex posttranslational modification (PTM). Glycoproteomics has become important for many life science disciplines, in particular for biomedical and biopharmaceutical research [3][4][5]. Glycopeptide