Semisynthesis, characterisation, and antibacterial evaluation of a novel lecanoric acid-derived amide library

• Ethan D. Abbott,
• Sasha Hayes,
• Jonathan M. White,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2026, 22, 1023–1032, doi:10.3762/bjoc.22.81

• ) [1]. Through this partnership, the alga provides food for both itself and the fungal symbiont by reducing atmospheric CO2 into organic sugars. The fungal partner protects the organism from UV exposure, parasitic attacks, and animal predators by producing a diverse range of natural products [2][3]. Of

Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies

• Antonio Angelastro,
• Jonathan Bargh,
• Subhajit Guria,
• Victor Laserna and
• Louis Luk

Beilstein J. Org. Chem. 2026, 22, 857–881, doi:10.3762/bjoc.22.67

• Knoevenagel–Michael addition (TKM) conjugation to enable production of glycoengineered high DAR ADCs [129]. Qasba’s engineered bovine galactosyltransferase (β4GalT1(Y289L)) is an elegant example of using glycosyltransferases to remodel glycans of target protein with non-natural sugars (e.g., GalNAz), leading

• of azido-carrying nucleotide sugar analogues (UDP-GalNAz), thereby introducing the bioorthogonal handle on the glycan [131][132]. Similarly, sialyltransferases, featuring remarkable substrate promiscuity, have also been exploited to install non-natural sugars on glycans [115][116][117][118][119

• sugars such as Ac4GlcNAz (34), Ac4ManNAz (35) and Ac4GalNAz (36) into cellular glycosylation pathways for bioorthogonal labelling; c) in vitro glycoengineering employs chemical (e.g., periodate) and/or enzymatic remodelling including the use of engineered oxidases (galactose oxidase

Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• fragments of natural molecules such as steroids, peptides or sugars, its solubility in water improves, thereby increasing the possibility of potential biological activity. In 2020, Martín and colleagues investigated fullerene 50 as a dipolarophile in 1,3-dipolar cycloaddition with azomethine ylide based on

Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers

• İlknur Polat,
• Selçuk Eşsiz and
• Emine Salamci

Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40

• azidomorphine (4) are utilized as pharmaceuticals (Figure 1) [1][6][7][8][9]. Additionally, recent studies demonstrated that nonglycosyl azides hamper glycan acceptance by carbohydrate-processing enzymes [10][11]. Moreover, azido sugars are used directly in cell biology studies. Therefore, synthetic

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• ]. Glutamine serves as a nitrogen donor for the biosynthesis of asparagine, amino sugars, and nucleotides. Glutamine is also hydrolyzed to glutamate by glutaminase (GLS) enzymes, which are often overexpressed in cancer cells. The resulting glutamate supports the biosynthesis of glutathione and can be

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• sugars (Figure 1) [42][43][44][45][46][47][48]. More specifically cycloaddition reactions of nitrones (1,3-dipoles) with N-aryl-substituted maleimides (electron-poor dipolarophiles) are a highly popular and versatile method for the formation of regio- and stereoselective pyrrolo-isoxazolidine-fused ring

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• intermediate in synthesis [1][2]. Several nucleoside analogue drugs are prepared using γ-butyrolactones, that when reduced give pentose sugars that can be used as glycosyl donors [3][4]. A number of these clinically used drugs contain fluorine as a hydroxy bioisostere at C2, most notably gemcitabine (1) and

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• such as bagasse, corncobs, stalks, switchgrass and hardwoods [156][157][158][159][160][161][162], thanks to preliminary selective dissolution and depolymerization of hemicellulose into pentose sugars. Deep eutectic solvents were recently shown to allow fractionation of lignin and production of furfural

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• feature asymmetrically distributed functional groups across their two pyranose rings, emphasizes the importance of robust, stereoselective synthetic strategies capable of producing fully orthogonally protected 1,1′-linked sugars suitable for selective chemical modification. This review highlights recent

• innovative, specialized approaches. While the synthesis of α,α-1,1'-linked nonreducing sugars was already comprehensively reviewed [36][37], the construction of β,β- and β,α-1,1'-glycosides has received noticeably less attention. This review provides an overview of the most recent developments in 1,1

• synthesis of symmetrically functionalized nonreducing disaccharide-based molecules. However, most biologically active molecules that contain nonreducing sugars are characterized by the presence of non-symmetrically distributed functional groups, which requires the use of selectively orthogonally protected

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• 113a–d, which are valuable precursors of oxetane nucleosides (Scheme 29) [77]. The triflates were prepared from the corresponding 1,2-O-isopropylidenepentofuranose sugars in 4 steps and then treatment with methanolic K2CO3 smoothly induced the ring contraction, affording the oxetane products in 70–82

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• scaffolds – alkanes – then we will progress to ethers, alcohols, sugars, amines (and their derivatives), carbonyl compounds, peptides, and finally sulfur-containing compounds. By arranging the material in this way, we hope that newcomers to the field might be able to readily envisage ways to apply these

• pendant aryl moiety, is better for target-binding and hence 41 is a ≈10-fold more potent inhibitor of BACE-1 than 40. Several further examples of cyclic ethers will be examined in section 5 (sugars). The anomeric effect applies in acyclic ethers, too. Consider the non-fluorinated scaffold, Ph–O–CH3 (42

• progress from ethers (section 2) to a closely related class of molecules, namely, the alcohols. The focus here in section 3 will be mostly on simple examples; more complex poly-ol examples will be discussed in section 4 (sugars). Taking the example of a simple alcohol such as ethanol, consider what happens

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• thiourea [112], keeping acetyl or benzoyl protection intact (Scheme 7) [113] which contributed to the selective deprotection of sugars in systematic oligosaccharide synthesis. The chloroacetyl group can also be similarly selectively deprotected with other reagents like N,N-pentamethylene thiourea [114][115

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• their activity against various types of cancer. N-Glycosides of indigo, indirubin, and isoindigo, blue, red, and yellow sugars, turned out to be of special interest because of their high cancerostatic activity and structural novelty. The present article provides an account on the synthesis and

• , indirubin, and isoindigo which can be regarded as blue, red, and yellow sugars, respectively. Review Indigo-N-glycosides (blue sugars) In 2002, Laatsch and Maskey reported the isolation of the akashins A, B and C, indigo-N-glycosides, from terrestric Streptomyces (Scheme 2) [17][18]. These natural products

• -mannose (14) afforded indigo-N-mannoside α-15a, albeit, in low yield (Scheme 11) [21]. Deacetylation afforded product α-15b. Indirubin-N-glycosides (red sugars) In contrast to indigo, indirubin is a non-symmetrical compound containing an amine- and an amide-type nitrogen atom. In our group, we developed a

Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

• determinants that govern specific molecular interactions. Keywords: computational tools; glycan–protein interactions; MD; molecular recognition; Review Introduction Carbohydrates also referred to as saccharides, sugars, or glycans, constitute one of the main building blocks of biomolecules, alongside lipids

• of different and particular structures [7][8]. Additionally, glycans can adopt a wide variety of different shapes; five-membered ring sugars can exhibit envelope and twist conformations usually represented on a pseudo-rotational wheel; while six-membered ring structures can adopt chair (C), boat (B

• , such as in the case of 1-6 linked sugars, an additional torsion, namely ω (O6–C6–C5–O5), must be defined and three staggered conformers, denoted as gg/tg/gt (ω angles of −60°/180°/60°, respectively), should be considered (Figure 1). Longer and branched glycans exhibit heightened structural dynamics

Monitoring carbohydrate 3D structure quality with the Privateer database

• Jordan S. Dialpuri,
• Haroldas Bagdonas,
• Lucy C. Schofield,
• Phuong Thao Pham,
• Lou Holland and
• Jon Agirre

Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83

• glycans of that type, and the format of the data inside each of these glycan types is identical. The data contained in each glycan entry is shown in Table 1. Each entry contains information about the protein chain attachment, the number of sugars in the glycan, the WURCS2.0 code [25], the standard

• available alongside the Privateer Web App [26], https://privateer.york.ac.uk/database. The first section of this visual report displays a global outlook on the validity of the model through two graphs. The first graph shows the conformational landscape for the pyranose sugars. For a sugar model to be deemed

• of the tree is the glycan information, separated into glycan types. Each glycan also contains a list of sugars, with a range of validation information and a list of linkage with torsion angle information. Tree visualisation was created with jsoncrack.com. Left: Graphical representation 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

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

• Michael O. Akintubosun and
• Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

• noticed that some other enzymes from this PFAM are also paired with aminotransferases to generate amino sugars found in natural products [25][26], so we looked to see if aminotransferases are commonly found by PF01408 sequences. We observed three separate aminotransferase PFAMs near many of the PF01408

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

• biopolymer have been established decades ago and are commonly used in a routine and automated manner. However, the development of such technology for the sequencing of the third class of biological polymer – glycans, also known as carbohydrates, saccharides, or "sugars" – lags far behind. This lack of

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• ′′′′. The linkages in the sugar moiety were determined based on the HMBC correlations of H-1′/C-3, H-1′′/C-2′, H-1′′′/C-3′′′, and H-1′′′′/C-2′′ and the SSCCs of the anomeric protons. The sugars contained in 1 and their absolute configurations were confirmed by analyzing the monosaccharide mixture obtained

• ; HRESIMS (m/z): [M + Na]+ calcd for C35H47NO21SNa, 872.2253; found, 872.2241. Identification of sugars in 1 and 2 Compound 1 (5 mg) was dissolved in 0.5 M hydrochloric acid in a glass centrifuge tube and heated at 95 °C for 2 h. The solution was neutralized with 0.5 M NaOH and concentrated in vacuo. To the

• nm was performed using a photodiode array detector. Compounds 2, 6, and 7 were derivatized and analyzed in a similar manner. Furthermore, derivatives of authentic sugars were analyzed, and peaks were observed at 8.34 (ᴅ-mannose), 12.17 (ᴅ-galactose), 12.74 (ʟ-glucose), 13.96 (ᴅ-glucose), 15.18 (ʟ

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• alcohol 66 can be lithitated and reacted with a range of electrophiles, even without the need for a Lewis acid catalyst, and good levels of stereoinduction can be achieved. The method was used for the synthesis of a range of hexose sugars, as well as iminosugars (viz 66 → 67 → 68), wherein the piperidine

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• studies, one of us (M. R. E. A.) felt intrigued by the potential of chemical hybridization of cholesterol through simple connections of pharmacophores including sugars, chalcones, quinolone, theophylline, and ferrocene using click chemistry [9][10][11]. Following this strategy, cholesterol was

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

• Sanaz Ahmadipour,
• Alice J. C. Wahart,
• Jonathan P. Dolan,
• Laura Beswick,
• Chris S. Hawes,
• Robert A. Field and
• Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

• = red, phosphorus = purple, chlorine = green, hydrogen = pink. C6–Cl is the gg rotamer (from the Cl6–C6–C5–O5 torsion angle). GMD function with probe 19 over 120 min (GMD (100 µg/mL), GDP sugars (50 µM), NAD+ (200 µM)). Dotted trace dictates expected fluorescence output following spiking with GDP-Man 1

Synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides

• Md Azadur Rahman,
• Kana Kuroda,
• Hirofumi Endo,
• Norihiko Sasaki,
• Tomoaki Hamada,
• Hiraku Sakai and
• Toshiki Nokami

Beilstein J. Org. Chem. 2022, 18, 1133–1139, doi:10.3762/bjoc.18.117

• indicated that thus-generated oligosaccharides 2c–4c, with a lower oxidation potential, also consumed electricity and converted to the corresponding hydroxy-substituted sugars, as observed by MS analysis. Thioglycoside 1d (Ar = 2,4-F2C6H3, Eox = 1.73 V vs SCE), which had the highest oxidation potential

• as the optimal amount of electricity to prevent formation of byproducts, such as hydroxy-substituted sugars that carry an anomeric hydroxy group instead of the ArS group. Although we tested other ammonium triflates, such as tetraethylammonium triflate and 1-butyl-1-methylpyrrolidinium triflate as

• obtained at T1 = −60 °C and T2 = −30 °C, although heptasaccharide 7a was not produced. MALDI–TOF MS spectra indicated the formation of byproducts derived from longer oligosaccharides at T1 = −30 °C and T2 = −30 °C (Figure 5). The relative intensity of the molecular ion peaks of hydroxy-substituted sugars

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• pentaerythritol homoglycocluster reported by the Carvalho group [17] and a C-sialoside bearing phenylpropyl group at C-2 [18] (Figure 1C). In the context of mimicking the terminal sugars α-ᴅ-Neu5Ac(2,3)-β-ᴅ-Gal of Trypanosoma cruzi mucins to obtain potent TcTS inhibitors, our group previously synthesised a small

• ) and compounds were visualised by UV irradiation (λ = 254 nm) and/or dipping in ethanol/sulfuric acid (95:5 v/v) followed by heating. A Biotage SP4 flash chromatography system was used for purification of the protected sugars with normal phase silica (pre-packed SNAP Ultra cartridges). Deprotected

• sugars (final products) were lyophilised using a Büchi Lyovapor L-200 freeze dryer. 1H, COSY, 13C, DEPT-135 and HSQC NMR spectra were recorded on a Bruker Avance III 400 MHz spectrometer at 298 K. Chemical shifts (δ) recorded in CDCl3 and D2O are reported with respect to the solvent residual peak at 7.26

Chemical and chemoenzymatic routes to bridged homoarabinofuranosylpyrimidines: Bicyclic AZT analogues

• Sandeep Kumar,
• Jyotirmoy Maity,
• Banty Kumar,
• Sumit Kumar and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2022, 18, 95–101, doi:10.3762/bjoc.18.10

• anomeric triacetylated sugars 19a,b with thymine and uracil in the presence of BSA and TMSOTf in acetonitrile afforded nucleosides 20a,b, respectively in high yields. The deacetylation of these nucleosides was carried out using K2CO3 in a solvent mixture of methanol and water (9:1) to afford nucleoside 21a