Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• showed that the activity of a difunctional organocatalyst in lactose hydrolysis was improved 5.2-fold by immobilisation on different solid supports that mimic the active site channels of enzymes [113]. In a solid-supported system, the solvent can exert a different influence on the catalytic activity

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

• mL−1 tetracycline and grown at 200 rpm and 37 °C overnight. One liter of autoinduction media (20 g L−1 tryptone, 10 g L−1 yeast extract, 50 mM NH4Cl, 2 mM MgSO4, 0.5% glycerol, 17 mM KH2PO4, 72 mM K2HPO4, 0.05% glucose, and 0.2% lactose) supplemented with 10 μg mL−1 ampicillin and 1.5 μg mL−1

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• project with groups from Universities in Munich and Pennsylvania we are investigating carbohydrate–lectin interactions using programmable glycodendrimersomes based on synthetic glycans. We have earlier synthesized 2-[2-(2-azidoethoxy)ethoxy]ethyl (TEG-N3) glycosides of lactose, 3’-Su-lactose and LacdiNAc

• -linked TEG-spacer glycosides with per-acetylated lactose and 2-phthalimidoglucosamine [1][2] worked well with 2-chloroethanol as a spacer (68%, pure α) but failed with the TEG-Cl spacer [12], why we instead decided to use a thioglycoside donor to introduce the spacer. To ensure α-selectivity a di-tert

• 10 furnished target 1 in a 90% yield. Formation of a stannylidene acetal via tin-activation was employed to achieve selective 3’-O-sulfation of compound 1 [27], with a variety of conditions being attempted (Table 1). With a TEG-N3 lactose compound, tin-activation was performed with Bu2SnO in

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• structure is an important scaffold which can be found in many pharmaceutical active natural products and synthetic medicinal compounds [2]. Pramanicin, for example, is a 2-pyrrolidone-containing natural product isolated from a lactose-containg liquid fermentation of a sterile fungus growing in grass which

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

• both enzymes (Figure 3A) (and TcTS transferase activity in the presence of an acceptor substrate, such as lactose – Figure 3B) by releasing the fluorophore 4-methylumbelliferone (MU) for detection upon cleavage of the substrate 2'-(4-methylumbelliferyl) α-ᴅ-N-acetylneuraminic acid (MUNANA). Compounds

• described by Neres and co-workers [34]. Briefly, TcTS assay was performed in duplicate in 96-well plates containing 200 mM phosphate buffer solution pH 7 (20 μL), 0.8 mg/mL recombinant enzyme (20 μL), 5 mM lactose (20 μL) and 5 mM inhibitor (20 μL) solutions. This mixture was kept for 10 min at 25 °C

• lactose and with 40 μL buffer. The data from three independent experiments were analysed with GraphPad Prism software version 4.0 (San Diego, CA, USA). Inhibition percentages were calculated according to the equation: % I = 100 [1 (Vi/V0)], where Vi is the velocity in the presence of inhibitor and V0 is

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

A consensus-based and readable extension of Linear Code for Reaction Rules (LiCoRR)

• Benjamin P. Kellman,
• Yujie Zhang,
• Emma Logomasini,
• Eric Meinhardt,
• Karla P. Godinez-Macias,
• Austin W. T. Chiang,
• James T. Sorrentino,
• Chenguang Liang,
• Bokan Bao,
• Yusen Zhou,
• Sachiko Akase,
• Isami Sogabe,
• Thukaa Kouka,
• Elizabeth A. Winzeler,
• Iain B. H. Wilson,
• Matthew P. Campbell,
• Sriram Neelamegham,
• Frederick J. Krambeck,
• Kiyoko F. Aoki-Kinoshita and
• Nathan E. Lewis

Beilstein J. Org. Chem. 2020, 16, 2645–2662, doi:10.3762/bjoc.16.215

• ). Similarly, galactofuranose, a common fungal monosaccharide, would be written “A^” Open form rule indicates that if the MS at the reducing end is open – a linear rather than cyclic MS, then the final character to the right of the string should be "o". For example, lactose, galactose β-linked to glucose would

Computational tools for drawing, building and displaying carbohydrates: a visual guide

• Kanhaya Lal,
• Rafael Bermeo and
• Serge Perez

Beilstein J. Org. Chem. 2020, 16, 2448–2468, doi:10.3762/bjoc.16.199

• the tools available for the representation of a simple disaccharide: lactose (β-D-Galp-(1→4)-D-Glcp). Figure 2 shows how different web-available platforms rendered it. On the one hand, thanks to the unified nomenclature, there is no ambiguity regarding the nature of the carbohydrate represented. On

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

• Laura Sršan and
• Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

• -linked structures are N-acetylglycosylamines, glucose, galactose, mannose, cellobiose, lactose, and maltose [19]. Therefore, we intended to prepare glycopeptide structures containing these sugars in a stepwise way, up to tripeptides. An orthogonal Fmoc/t-Bu protecting group strategy was chosen along with

• synthesis of a series of new glycopeptides containing asparagine, tryptophane, alanine, and phenylalanine linked to various saccharides, such as glucose, galactose, mannose, cellobiose, lactose, and maltose. We further compared two common peptide coupling procedures that use HBTU and HATU, respectively. We

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

• Alexander Dahlqvist,
• Axel Furevi,
• Niklas Warlin,
• Hakon Leffler and
• Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

• to attenuate such processes [3][10][11][14]. Experimental galectin inhibitors have often been developed with a close resemblance to natural disaccharide ligands, such as lactose and N-acetyllactosamine (lacNAc) [15] via thiodigalactosides [16][17][18][19], as adding a second monosaccharide unit to

• those of lactose and LacNAc for galectin-3 and also to have selectivity over other galectin-1 [22][23]. Later, combining non-natural thiophenyl aglycons with C3-triazole groups at D-galactose led to the discovery of high affinity and selective galectin-3 inhibitors [24]. In this work, we present a

• C-galactoside aglycons, we performed a 200 ns molecular dynamic simulation of 1b in the complex with galectin-1 and galectin-3. Starting conformations were selected with the galactopyranose of 1b positioned overlapping with the positions of the lactose or N-acetyllactosamine galactopyranoses in

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• increased safety in NPC animal models [12]. Moreover, superstructures of cyclodextrins like mono-lactose-appended β-CD [13] and biocleavable pluronic/β-CD-based polyrotaxanes [14] as well as PEG-lipid micelles (DSPE-PEG) in combination with HP-β-CD [15] have shown enhanced therapeutic effects and exhibit a

AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

• Jayashree Rajput,
• Srinivas Hotha and
• Madhuri Vangala

Beilstein J. Org. Chem. 2018, 14, 682–687, doi:10.3762/bjoc.14.56

• -tri-O-benzoyl-α-L-rhamnopyranosyl azide (12) in 71% yield. Furthermore, C5-O-TBDPS-protected perbenzoylated arabinofuranose (Table 2, entry 4) afforded the desired azide 13 in 70% yield along with some amounts of desilylated product. Furthermore, azidation of perbenzoylated maltose and lactose (Table

Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• lactose-2-aminothiazoline conjugate as a CT antagonist. Its affinity for CTB was determined by monitoring the change in fluorescence of tryptophan-88, located in the GM1 binding site, upon titration of the protein with the inhibitor. Compound 6 showed excellent binding with a Kd value of 23 µM [41

• length increase. Hence, they concluded that the length, size and chemical nature of the ligand has a major effect on binding with the protein toxin. While the ganglioside GM1 head group is the highest affinity natural ligand for CTB, galactose and lactose (Figure 8) head groups have also been used for

• synthesising bivalent and tetravalent multivalent inhibitors and showed substantial gains in binding affinity in comparison to the corresponding monovalent ligands. Pieters and co-workers attached a lactose-derived monomeric ligand to the dendrimer 18, and found that there was an affinity and potency gain from

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• debenzylation followed by global acetylation to afford product 30. The extension of this approach to convergent oligosaccharide synthesis and reiterative sequencing in presented in Scheme 8. Thus, maltose and lactose disaccharide building blocks were linked via the xylylene tether, and the resulting compound 31

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• ). Encouragingly, disaccharides LacNAc and lactose derivatives are compatible (Table 6, entries 5 and 6) [84]. Fairbanks and colleagues have also devised a two-step one-pot method to obtain glycosyl click products [85]. The authors utilized 2-azido-1,3-dimethylimidazolium hexafluorophosphate (ADMI) [86], which

Aqueous semisynthesis of C-glycoside glycamines from agarose

• Juliana C. Cunico Dallagnol,
• Alexandre Orsato,
• Diogo R. B. Ducatti,
• Miguel D. Noseda,
• Maria Eugênia R. Duarte and
• Alan G. Gonçalves

Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121

• -1-aminodisaccharides (those prepared from lactose, maltose and cellobiose) [23]. The primary stage of our optimization to obtain 3 consisted in evaluating the influence of different ammonium salts or ammonium hydroxide as nitrogen source to the reductive amination reactions (Table 1, entries 1–6

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• transporter to be determined was the one of lactose permease LacY [60]. Later on, the structures of different bacterial homologues were also solved. It is only recently that the structure of human GLUT1 was reported [61]. Nevertheless, the joint difficulty to solubilize and crystallize membrane proteins

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• intracellular stability. Liz-Marzan et al. assessed the ability of glycan ligands to reduce the protein corona formation around rod-shaped AuNPs [71]. Lactose- and polyethylene glycol (PEG)-functionalized gold nanorods demonstrated similar ability in reducing the interaction with proteins, when compared to

• citrate-AuNPs. Moreover, comparing the macrophage NP uptake, the authors demonstrated that the lactose shell can prevent phagocytosis more efficiently than PEG coating. A deep knowledge of any aspect which can influence the GAuNP behavior is important to drive the correct design of the nanosystem and is

• signals [80]. The greatest advantage in using SERS is the possibility to provide unique spectral signatures describing glycan–protein interactions. Boons and co-workers prepared label-free microarrays of lactose-coated AuNPs (diameter of 60 nm) to study lactose galectin (i.e., galectine 1 and galectin 3

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• of novel FCDs with improved properties. For example, simple monosaccharides such as glucose, glucosamine, mannose, fructose and their derivatives and common disaccharides, e.g., sucrose, lactose, and maltose have been employed to prepare fluorescent carbon dots (FCDs) using different methodologies

Silyl-protective groups influencing the reactivity and selectivity in glycosylations

• Mikael Bols and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12

• been employed by Gervay–Hague and co-workers to protect glycosyl donors [13][14][15][16][17]. The reaction of a hexa-TMS-protected lactose derivative 10 with TMS iodide converted it to glycosyl iodide 11 that glycosylated alcohols in good yields (Scheme 4). The TMS protective groups are however rather

Synthesis of multi-lactose-appended β-cyclodextrin and its cholesterol-lowering effects in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2017, 13, 10–18, doi:10.3762/bjoc.13.2

• synthesize a novel multi-lactose-appended β-CD (multi-Lac-β-CD) and to evaluate its cholesterol-lowering effect in U18666A-treated HepG2 (NPC-like HepG2) cells. Further, the study aimed at delivering β-CD to hepatocytes via cholesterol-accumulated HepG2 cells, and indicated that the newly synthesized multi

• -Lac-β-CD had an average degree of substitution of lactose (DSL) of 5.6. This newly synthesized multi-Lac-β-CD was found to significantly decrease the concentration of intracellular cholesterol with negligible cytotoxicity as compared to HP-β-CD. An increased internalization of TRITC-multi-Lac-β-CD

• NPC-like HepG2 cells via asialoglycoprotein receptor (ASGPR)-mediated endocytosis. Keywords: asialoglycoprotein receptor; cholesterol; cyclodextrin; lactose; Niemann–Pick type C disease; Introduction The Niemann–Pick type C (NPC) disease is a lipid storage disorder with the accumulation of membrane

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• atom containing ligand as well as PVL lectin from Psathyrella velutina [26] using methyl β-D-selenoGlcNAc. Recently, the crystal structure of human galectin-9 in complex with a selenium-containing lactose disaccharide has been described [27]. In 2014, we have characterized the toxin Tectonin-2 from the

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

• Felicia D’Andrea,
• Giorgio Catelani,
• Lorenzo Guazzelli and
• Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

• enantioform of the four diastereoisomeric aldohexos-5-ulose series. A general approach was developed starting from β-D-galactopyranosides, including the commercially and cheaply available lactose [36][37][38]. Presented here is the extension of the above synthetic route to inositols using aldohexos-5-uloses

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• for peracetylated-β-D-lactose 15a (entry 15, Table 2) and peracetylated rutin 17a (entry 17, Table 2) where the remaining 50% of product was constituted by a mixture of different non-fully acetylated forms, even after more than one acetylation run. Moreover, peracetylation of rutin (17), which is the