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

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• sulfur atom at the 3’-position, these compounds have proved to be structurally potent nucleoside analogues, and the best example is BCH-189. The majority of methods traditionally involves the chemical modification of nucleoside structures. It requires the creation of artificial sugars, which is

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• methodology utilized in Scheme 5 had been successfully employed for the preparation of C-glycopyranosyl derivatives of common and uncommon sugars like α-gluco, α-manno, β-altro, β-ido, α- and β-gulo, β-talo, α-galacto, and α-allo C-glycopyranosides [42]. Vinylated derivatives of aldopentoses 11 were treated

• with Hg(OAc)2 affording the corresponding cyclized pyanosylmethylmercuric chloride derivatives 12 (Scheme 5). This methodology can be used to synthesize rare C-glycosyl carbohydrates from easily available sugars. In a similar manner, stereoselective cyclization of C-glycosyl amino acid derivative 13

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• polymerization [18], C) chemical synthesis. The use of enzymes has undeniable advantages because it offers the possibility to use unprotected sugars as substrates and guarantees remarkable control of the regio- and stereoselectivity during glycosylation. Mono- or oligosaccharides bearing a reactive leaving group

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

• -form helix" by the study authors [41]. Despite the much larger displacement of the bases from the helix axis, the base stacking in the P-form helix resembles that of an A-form DNA duplex. The sugars of a DNA strand adopt C3′-endo conformations with an average interphosphate distance of ≈6 Å, which is

Chemical synthesis of C6-tetrazole ᴅ-mannose building blocks and access to a bioisostere of mannuronic acid 1-phosphate

• Eleni Dimitriou and
• Gavin J. Miller

Beilstein J. Org. Chem. 2021, 17, 1527–1532, doi:10.3762/bjoc.17.110

• -protected donors, suitable for iterative oligosaccharide synthesis. The development of these building blocks is showcased to access anomeric 3-aminopropyl- and 1-phosphate free sugars containing this non-native motif. Keywords: alginate; glycosyl 1-phosphate; non-native monosaccharide; tetrazole; uronate

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• of deoxyribonucleic acids (DNA) or ribonucleic acids (RNA), which contain either a purine or pyrimidine nucleobase and a furanosyl moiety of pentose sugars, 2′-deoxyribose or ribose [1][2]. Nucleotides are constituted by addition of a phosphate group at the 5′-position of the nucleosides and these

Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

• Vojtěch Hamala,
• Lucie Červenková Šťastná,
• Martin Kurfiřt,
• Petra Cuřínová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

• . Keywords: amino sugars; deoxyfluorination; fluorinated carbohydrates; hexosamine hemiacetals; thioglycosides; Introduction Fluorinated carbohydrates are versatile carbohydrate mimetics used to probe or manipulate the recognition of carbohydrates by carbohydrate-binding proteins or carbohydrate-processing

• molecules [12]. The fluorination of sugars is also a promising strategy to improve unfavorable pharmacokinetic properties of natural carbohydrates such as low lipophilicity [13][14][15][16] and fast metabolic degradation [17][18][19]. Over the last few years, considerable effort has been expended on the

• -catalyzed hydrogenolysis in ethanol/acetic anhydride appeared to be a logical deprotection step [26], the desired fluoro sugars were contaminated with varying quantities of unidentified byproducts. However, clean debenzylation was achieved by first converting the azide to an acetamide on reaction with

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

• group between the sugars in DNA and RNA is at the origin of the vastly expanded fold [29][30][31][32] and functional spaces of RNA [33][34][35][36][37][38][39]. Perhaps less known is the fact that the sugar moiety in the backbone of a nucleic acid determines the base pairing priorities. For example, in

• adenosine [114]. This duplex adopted an overall A-form, with the sugars in the C3'-endo orientation and the two, well solvated methoxy groups, pointing into the relatively wide minor groove of the duplex. It was shown that as the number of carbons in the 2'-O-alkyl chain increased, so too did the

Simulating the enzymes of ganglioside biosynthesis with Glycologue

• Andrew G. McDonald and
• Gavin P. Davey

Beilstein J. Org. Chem. 2021, 17, 739–748, doi:10.3762/bjoc.17.64

• glycolipid or some other oligosaccharide, the nucleotide A is the product of the donor and xB is the acceptor product. The strings can be seen as a compression of the familiar condensed linear IUPAC notation, using a single-letter notation to represent sugars, with upper-case denoting ᴅ, and lowercase, the ʟ

• , sugars, and are read from right to left starting with the base (reducing-end) sugar. The letters a and b are reserved for α and β-anomers, respectively, while brackets are used to delimit branches, and the letter T is used to denote the connection point to ceramide, or to another conjugate depending on

• before sugars units, and multiple modifiers on the same monosaccharide are again ordered by linkage position, from lowest to highest, reading right to left. Nomenclature of gangliosides Gangliosides are commonly labelled according to the abbreviated Svennerholm [20] nomenclature, or else by the expanded

Direct synthesis of anomeric tetrazolyl iminosugars from sugar-derived lactams

• Michał M. Więcław and
• Bartłomiej Furman

Beilstein J. Org. Chem. 2021, 17, 115–123, doi:10.3762/bjoc.17.12

• Michal M. Wieclaw Bartlomiej Furman Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland 10.3762/bjoc.17.12 Abstract Herein we present the direct asymmetric synthesis of tetrazole-functionalized 1-deoxynojirimycin derivatives from simple sugars via a

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

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

• of the PDA liposomes to about 48% of the initial value (Figure 10B). The calculated binding constant from Stern–Volmer analysis of fluorescence titration is 1.5 × 106 M−1. This system is very selective towards LPS as other analytes, including nucleotides, anionic sugars, and ctDNA did not increase