Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system

• David Liese,
• Hans Henning Wenk,
• Xin Lu,
• Jochen Kleinen and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232

• Pseudomonas aeruginosa, a Gram-negative rod-shaped bacterium [5][6][7][8]. RL are built up by one or two rhamnose sugar units as well as one to three β-hydroxy fatty acids, which can also be unsaturated. These highly functional biomolecules exhibit interesting biological and antibacterial properties, as

• micelles are entangled at ambient temperature, so that a network-like structure is formed. An illustration of the formation of RWLM by the dirhamnolipid esters is shown in Figure 9. The hydrophilic sugar parts are oriented towards the interior of the micelle and the lipophilic alkyl chains are pointed

Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases

• Julia N. Artsemyeva,
• Ekaterina A. Remeeva,
• Tatiana N. Buravskaya,
• Irina D. Konstantinova,
• Roman S. Esipov,
• Anatoly I. Miroshnikov,
• Natalia M. Litvinko and
• Igor A. Mikhailopulo

Beilstein J. Org. Chem. 2020, 16, 2607–2622, doi:10.3762/bjoc.16.212

• problems associated with the reversibility of enzymatic phosphorolysis/synthesis reactions, along with the solubility of heterocyclic bases and accessibility of PF-1Pis. Despite all this, in a number of cases these problems have been successfully solved and, as a result, the desired base and/or sugar

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• Department of Chemistry, Center for Molecular Materials (CM2), Bielefeld University, 33615 Bielefeld, Germany 10.3762/bjoc.16.207 Abstract A sugar-functionalized water-soluble tribenzotriquinacene derivative bearing six glucose residues, TBTQ-(OG)6, was synthesized and its interaction with C60 and C70

• motif. In the work presented here, we have introduced sugar motifs that possess good water solubility and biocompatibility [36][37][38] at the six outer peripheral positions of the TBTQ framework to provide, for the first time, a water-soluble TBTQ-based host bearing an extended cavity. The complexation

• Discussion Synthesis of the host TBTQ-(OG)6. The sugar-functionalized host TBTQ-(OG)6 was synthesized starting from the known compound TBTQ-(OH)6 (Scheme 1) [31][32][33]. The reaction of TBTQ-(OH)6 with propargyl bromide in the presence of potassium carbonate gave the hexakis-propargyl ether, TBTQ-(OP)6, in

Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding

• Christopher B. Barnett,
• Tharindu Senapathi and
• Kevin J. Naidoo

Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206

• approach, we aim to use the tools and workflows available as part of the Galaxy project to analyze MD simulations to find out if the sugar moiety of the Tn-antigen binds directly to the antibody. Further, if the sugar does not bind directly (as found previously), then we will use these analyses to observe

• how the sugar modulates binding. Methods The inputs, simulation scripts, Galaxy workflows (a series of tools and dataset actions that run in sequence), and data for these simulations are available at https://github.com/chrisbarnettster/bjoc-paper-2020-sm. Simulation There is an increasing number of

• pre-organized for antibody binding. A Ramachandran plot can be used to understand the role of the sugar moiety, by comparison of the dihedral angle distribution of the glycosidic linkage between the glycan and peptide portion of the Tn-antigen (Figure S3 in Supporting Information File 1). In solution

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• ligand consisting of a fusicoccane diterpene core combined with different sugar moieties was designed to improve its properties as molecular glue for the 14-3-3/p53 complex [105]. Upon peptide binding in the absence of ligand, the 14-3-3 resonances of the binding site show reduced signal intensities. The

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

• structure is output in the specified notation: either ASCII IUPAC sugar nomenclature or a graph which can be rendered in different themes which include Heidelberg, Oxford, Tokyo, CFG and extended CFG (Figure 4, middle). The output images for the glycan structure and the legends can be saved and downloaded

• , it only uses the sugar units that are defined in GLYCAM. The topologies generated for glycosylated proteins and glycolipids are compatible with the OPLS [72] and AMBER [73] force fields. The topology for carbohydrate polymers is based on the GLYCAM force field. The user needs to provide the ceramide

• representation that twists and changes its orientation according to the relative position of following sugar residues, hence provides an important conformational detail in polysaccharides. Combination

A proposed sustainability index for synthesis plans based on input provenance and output fate: application to academic and industrial synthesis plans for vanillin as a case study

• John Andraos

Beilstein J. Org. Chem. 2020, 16, 2346–2362, doi:10.3762/bjoc.16.196

• scales that are several orders of magnitude longer than organism time scales. (4) Lignosulfonic acid liquor and sawdust were considered renewable inputs since they ultimately originate from trees. Ferulic acid and ᴅ-glucose were considered renewable inputs since they originate from sugar beet biomass [47

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• that the molecular size of the flavonoids and the length of the sugar chains have a greater impact on the assembly mode of supramolecular systems. Results and Discussion Host–guest interactions The host–guest interaction can be effectively observed using 1H NMR spectroscopy, and the mode of action of

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• -1–C-5 segment of thailanstatin methyl esters Both syntheses of the C-1–C-5 tetrahydropyran segment of thailanstatin A (7) utilize sugar precursors. In the Ghosh synthesis [31], the triacetyl ᴅ-glucal 60 is converted into the trans C-1-allylated tetrahydropyran 98 according to literature procedures

• C-1–C-6 tetrahydropyran fragments of FR901464 (1). The preparation of the C-1–C-5 tetrahydropyran fragment of the thailanstatins has, so far, utilized sugar-derived precursors. A variety of reactions have been utilized for union of these fragments via a diene segment. While a Ru-catalyzed cross

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• enzymes require an activated sugar donor uridine diphosphate (UDP)-Galf, which is synthesized from UDP-galactopyranose (UDP-Galp) by the enzyme UDP-Galp mutase [9] (Supporting Information File 1, Figure S1). The recently published GlfT2 X-ray structure with a UDP donor part [10] was used in the reaction

• -up of lipid-linked galactan precursors. The crude enzymes used in the assay allow for in situ synthesis of the acceptor for galactan polymerization, decaprenyl-P-P-GlcNAc-Rha (GL2), from endogenous decaprenyl phosphate and sugar nucleotides UDP-GlcNAc and TDP-Rha supplied in the reaction mixture

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• N-heterocyclic compounds such as phenanthridine, carbazole, and dibenzo[b,d]azepine. Simultaneously, Guo’s group published the arylation of nucleosides bearing a purine moiety. The transformation was regioselective and tolerated various substituents at the N9 position of the purine, including sugar

• synthetically meaningful σ-bromo esters. The mildness of the reaction conditions warranted tolerance of sensitive and/or biologically relevant sugar, menthol, and steroid motifs (Figure 37). The mechanistic studies conducted by Ackermann et al. clearly showed that the metallacyclic intermediates resulting from

Nonenzymatic synthesis of anomerically pure, mannosyl-based molecular probes for scramblase identification studies

• Giovanni Picca,
• Markus Probst,
• Simon M. Langenegger,
• Oleg Khorev,
• Peter Bütikofer,
• Anant K. Menon and
• Robert Häner

Beilstein J. Org. Chem. 2020, 16, 1732–1739, doi:10.3762/bjoc.16.145

• -Dod-NBD was obtained in 10 steps, starting from citronellol and tert-butyldimethylsilyl (TBDMS)-protected dodecanediol [39]. The reaction of either of the alcohols with the sugar phosphoramidite using ETT led to phosphite intermediates 1a and 1b, respectively. The intermediates were then oxidized with

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• conversion of cellulose and even spruce in a one-step hydrogenolysis reactions to form C4 to C6 sugar alcohols [20]. For the C6 sugar alcohols including the isosorbide formation, the yield was below 6% whatever catalyst was used at 160 °C, under 50 bar of H2 in a 36 mL stainless steel autoclave equipped with

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• -thioanhydro-α-D-gulopyranoside (84), the thietane-containing gulopyranoside [48] (Scheme 18). For the preparation of thioanhydro sugar derivatives, Cubero and co-workers treated methyl 6-S-acetyl-2,4-di-O-benzoyl-3-O-methanesulfonyl-6-thio-α-D-galactopyranoside (85) with methanolic sodium methoxide to

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• level of blood sugar in patients with type 2 diabetes and belongs to the dipeptidyl peptidase-4 (DPP-4) class of inhibitors [114][115]. This enzyme breaks down the incretins GLP-1 and GIP, gastrointestinal hormones released in response to a meal. By preventing the breakdown of GLP-1 and GIP, they are

• able to increase the secretion of insulin by the pancreas that modulates blood sugar level when it is high. Sitagliptin was granted FDA approval in October, 2006 [116]. Retagliptin phosphate: Retagliptin phosphate (184) is under investigation as a DPP-4 inhibitor for treating type-2 diabetes. It is an

• participating in the modulation of blood sugar levels by increasing insulin secretion. Consequently, GLP1R plays a key role in the development of drugs to treat diabetes mellitus [128][129][130]. 5.2.7. Sodium channel blockers (benzazepinone Nav1.7 blocker): Sodium channel blockers are used in the treatment of

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

• functional group that would require an additional protection orthogonal to the Fmoc/t-Bu protocol and the acetyl groups of the sugar moieties. However, numerous other natural or unnatural amino acids, functionalized or not, could be used for this reaction protocol. Results and Discussion For the synthesis of

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• installation of the1,3-diene units at the anomeric center of the future C-aryl glycoside (23) in high yields (94–98%, Scheme 24). Alternatively, an intramolecular enyne metathesis promoted by the first-generation Grubbs catalyst produced the spiro-C-aryl glycoside 24 from sugar enyne precursors (Scheme 25

Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose

• Lukáš Kerner and
• Paul Kosma

Beilstein J. Org. Chem. 2020, 16, 9–14, doi:10.3762/bjoc.16.2

• ; lipopolysaccharide; Introduction Glycosyltransferases are important enzymes that accomplish the transfer of activated sugar phosphates onto their respective acceptor molecules [1]. In most cases, nucleotide diphosphate sugars serve as the reactive species, but lipid-linked diphosphate derivatives are equally

Regioselectivity of glycosylation reactions of galactose acceptors: an experimental and theoretical study

• Enrique A. Del Vigo,
• Carlos A. Stortz and
• Carla Marino

Beilstein J. Org. Chem. 2019, 15, 2982–2989, doi:10.3762/bjoc.15.294

• . Regioselectivity responds to multiple steric and electronic factors present in both the glycosyl donor and acceptor, and they are characteristic for each particular sugar. Although relative reactivity values have been established for glycosyl donors, it has not been possible to do the same for glycosyl acceptors

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• the antifungal asperfuran [15], named glycoasperfuran. The absolute configuration of the sugar moiety was established by comparing the specific rotation of the aqueous layer of its acid hydrolysate ([α]D20 +30 (c 0.02, MeOH)) with that of 4-O-methyl-β-ᴅ-glucopyranose ([α]D25 +80 (c 1.3, MeOH)). This

• structurally related asperfuran had been reported as a moderately antifungal metabolite [15]. This suggested that the presence of the sugar moiety in glycoasperfuran (3) may have led to a loss of activity. Conclusion In the current study, the secondary metabolite profiling using HPLC–DAD–MS led to the

A green, economical synthesis of β-ketonitriles and trifunctionalized building blocks from esters and lactones

• Daniel P. Pienaar,
• Kamogelo R. Butsi,
• Amanda L. Rousseau and
• Dean Brady

Beilstein J. Org. Chem. 2019, 15, 2930–2935, doi:10.3762/bjoc.15.287

• the synthesis of glycomimetic products from sugar lactones, and for the synthesis of various pyrimidines. Proposed retrosynthesis of the free diol 1. Preparation of O-unprotected, trifunctionalized synthons from lactones. Preparation of a variety of β-ketonitriles. Supporting Information Supporting

Synthetic terpenoids in the world of fragrances: Iso E Super^® is the showcase

• Alexey Stepanyuk and
• Andreas Kirschning

Beilstein J. Org. Chem. 2019, 15, 2590–2602, doi:10.3762/bjoc.15.252

• natural products. Biotechnology is another way to harness fragrance components be it enzymatic or microbial. Nowadays engineered microbes are at hand that, e.g., produce scents, such as patchouli, by fermenting sugar. Patchouli is a complex mixture of sesquiterpenes ((−)-patchoulol, (+)-norpatchoulenol

Chemical synthesis of the pentasaccharide repeating unit of the O-specific polysaccharide from Escherichia coli O132 in the form of its 2-aminoethyl glycoside

• Debasish Pal and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2019, 15, 2563–2568, doi:10.3762/bjoc.15.249

• glycoside; diarrhea; galactofuranose; O-specific polysaccharide; total synthesis; Introduction O-Polysaccharides are the most complex molecular systems present in the bacterial cell wall owing to the presence of various sugar residues connected through diverse glycosidic linkages. These complex structures

• stereochemistry of the reducing end sugar. The challenging stereoselective glycosylation with the galactofuranosyl unit was achieved through a chemoselective glycosylation approach depending on the higher reactivity of the furanose derivative over the pyranose system. Structure of the target pentasaccharide

Indium-mediated C-allylation of melibiose

• Christian Denner,
• Manuel Gintner,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2019, 15, 2458–2464, doi:10.3762/bjoc.15.238

• carbohydrates at the anomeric position to obtain higher complex sugar structures. Prior to the establishment of these methods, synthetic approaches towards these compounds had to be performed on protected carbohydrates, increasing the number of synthetic steps intrinsically [1]. In 1991, Schmid and Whitesides

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

• and Research, Pune, Pune 411008, India 10.3762/bjoc.15.234 Abstract The intramolecular cyclization of a C-3-tetrasubstituted furanoid sugar amino acid-derived linear tetrapeptide afforded an oxazolone pseudo-peptide with the formation of an oxazole ring at the C-terminus. A conformational study of

• transporter for which an anion–anion antiport mechanism was established. Keywords: ion transport; oxazolone; peptidomimetics; pseudo-peptides; sugar amino acid; Introduction Tetrasubstituted α-amino acid (TAA)-derived peptidomimetics offer well-defined turn structures due to the presence of a

• conformation [5]. Amongst these, the use of sugar-derived TAAs in peptidomimetics is less explored. The linear tri-/tetrapeptides and spiro-peptides at the anomeric position of mannofructose are known [6][7][8]. Stick and co-workers have reported the synthesis of tetrasubstituted sugar furanoid amino acid