Synthesis of Streptococcus pneumoniae serotype 9V oligosaccharide antigens

• Sharavathi G. Parameswarappa,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2020, 16, 1693–1699, doi:10.3762/bjoc.16.140

• escape the host immune response [1][7]. These polysaccharides of SP consist of repeating units (RU) that range from di- to heptasaccharides that may be branched and/or charged [8]. Modifications such as O-acetylation, phosphorylation, and sulfation further increase CPS complexity. Many bacterial

• polysaccharides are O-acetylated [9][10]. Especially SP serotypes, such as 9 (A, V) and 18C differ in O-acetylation. Two O-acetylated serotypes (9V and 18C) are part of the commercial vaccine Prevnar® 13. The traditional CPS isolation approach produces varying length CPS with different degrees of acetylation. An

Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• . Polysaccharides and, among them, starch derivatives such as cyclodextrins (CD), have recently emerged as they are safe, of low cost and biodegradable. Cyclodextrin nanosponges (CD-NS) are crosslinked cyclodextrin polymers characterized by a nanosized three-dimensional network. The reactive hydroxy groups of CDs

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• with a production of 1011–1012 tons per year, followed by lignin as second most abundant raw material [16]. Lignin is a three-dimensional phenolic polymer and is responsible for the cementation of cellulose fibres in plants [17]. Hemicelluloses, predominantly xylan, are non-cellulosic polysaccharides

Convenient synthesis of the pentasaccharide repeating unit corresponding to the cell wall O-antigen of Escherichia albertii O4

• Tapasi Manna,
• Arin Gucchait and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2020, 16, 106–110, doi:10.3762/bjoc.16.12

• of devastating diarrheal infections in different countries [9]. The role of cell wall O-polysaccharides in regulating the virulence properties of bacteria is well established [10]. Recently, Naumenko et al. [11] reported the structure of the repeating unit of the cell wall O-polysaccharide of the E

• cell wall polysaccharides with suitable proteins, which include vaccines against Haemophilia influenza type b (Hib) [12][13], meningitis [14], pneumococcal infections [15][16] and enteric diseases such as cholera [17], diarrhea [18] and urinary tract infections [19]. Despite the possibility of

• isolating the polysaccharides by fermentation techniques, it is difficult to get a significant quantity of polysaccharide fragments from natural sources with adequate purity. Therefore, the development of chemical synthetic strategies is quite pertinent to obtain a requisite quantity of oligosaccharide

Automated glycan assembly of arabinomannan oligosaccharides from Mycobacterium tuberculosis

• Alonso Pardo-Vargas,
• Priya Bharate,
• Martina Delbianco and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2019, 15, 2936–2940, doi:10.3762/bjoc.15.288

• , Germany 10.3762/bjoc.15.288 Abstract Arabinomannan (AM) polysaccharides are clinical biomarkers for Mycobacterium tuberculosis (MTB) infections due to their roles in the interaction with host cells and interference with macrophage activation. Collections of defined AM oligosaccharides can help to improve

• the understanding of these polysaccharides and the development of novel therapeutical and diagnostic agents. Automated glycan assembly (AGA) was employed to prepare the core structure of AM from MTB, containing α-(1,6)-Man, α-(1,5)-Ara, and α-(1,2)-Man linkages. The introduction of a capping step

• chemical synthesis of AM is an attractive alternative. AM polysaccharides as large as 92-mers as well as many shorter AM oligomers have been prepared by solution-phase synthesis [16][17][18][19][20]. These multi-step syntheses are challenging and time-consuming. AGA reduces time and effort to access

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

• play a key role in determining and regulating the biology of these organisms [1] and act as the elicitor of the innate immune response [2]. As these polysaccharides can protect the bacteria concerned by killing the serum complements of the host system and can stop phagocytosis, they are extremely

Mechanochemical amorphization of chitin: impact of apparatus material on performance and contamination

• Thomas Di Nardo and
• Audrey Moores

Beilstein J. Org. Chem. 2019, 15, 1217–1225, doi:10.3762/bjoc.15.119

• contamination level results from the fact PTFE is very soft and easily scratched by chitin. Clear signs of wear were observed in PTFE jars after several runs, confirming the mechanism. Conclusion Milling is an effective way to amorphize polysaccharides. Amorphization is dependent on factors such as mass, impact

• increased hardness does not increase amorphization as max impact energy transfer to the sample has been achieved. This can give control over mixing or physical modification of the polysaccharides for mechanochemistry experiments and allow for better selection of milling media. Contamination has been

• of polysaccharides In a typical experiment, 200 mg of polysaccharide, chitin was placed in a jar equipped with one ball and milled in a MM 400 mixer mill for 30 min at 29.5 Hz. The resulting powder was used as is for analysis. Powder X-ray diffraction (PXRD) Sample diffractogram was recorded from 5

Convergent synthesis of the pentasaccharide repeating unit of the biofilms produced by Klebsiella pneumoniae

• Arin Gucchait,
• Angana Ghosh and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2019, 15, 431–436, doi:10.3762/bjoc.15.37

• -negative pathogenic organism causing pneumonia, urinary tract infections (UTI), intra-abdominal infections, meningitis, and pyrogenic liver abscesses in humans [1][2][3]. The bacteria have capsules in the outermost layers of the cells, which are composed of a variety of complex polysaccharides known as K

• -antigens [4]. The pathogenicity of K. pneumoniae relies on the structure of the capsular polysaccharides [5]. Besides a large number of polysaccharides present in the capsules, K. pneumoniae secrets a variety of polysaccharides which form biofilms for the protection of the organism from external agents [6

• ]. In addition, secreted polysaccharides from a particular strain also render pathogenicity of that organism. Since capsular polysaccharides of K. pneumoniae and polysaccharides secreted by it play an important role in the initial stage of infections [7], it is quite pertinent to develop therapeutics

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• -mannopyranoside-binding lectin [72]. The relatively high glycoside concentrations (in the mM range) used in this hemagglutination inhibition assays; however, indicate that the tested mono- and polysaccharides are not the optimal or native ligands for this lectin. Other mycobacteria, like Mtb, have since been

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• that, in addition to antimicrobial resistance, forms biofilms, a complex matrix of extracellular polysaccharides, polypeptides and DNA, which act as an additional protective barrier [30]. P. aeruginosa employs two lectins for biofilm formation and host–cell adhesion: proteins LecA and LecB [31][32

Synthetic avenues towards a tetrasaccharide related to Streptococcus pneumonia of serotype 6A

• Aritra Chaudhury,
• Mana Mohan Mukherjee and
• Rina Ghosh

Beilstein J. Org. Chem. 2018, 14, 1095–1102, doi:10.3762/bjoc.14.95

• SPn 6A in multicomponent vaccines like Pneumovax® has been recognized [15]. The low hydrolytic stability of the phosphodiester linkages in the clinical isolates of the SPn 6A polysaccharides poses a major drawback as it leads to low bioavailability [16]. Hence, the requirements of pure SPn 6A

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• moieties, then a molar optical rotation as large as ca. −80 deg dm−1 M−1 should be expected. By analogy with what observed for polysaccharides [41][42], differences with the observed values might be in principle ascribed to either electronic effects, or conformational rearrangements of the overall

New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• Daily Rodriguez-Padron Alina M. Balu Antonio A. Romero Rafael Luque Departamento de Química Orgánica, Grupo FQM-383, Universidad de Cordoba, Campus de Rabanales, Edificio Marie Curie (C-3), Ctra Nnal IV-A, Km 396, E14014, Cordoba, Spain 10.3762/bjoc.13.194 Abstract Polysaccharides from natural

• been an attractive option to imitate based on a fundamental and rational understanding [28][32]. In that sense, polysaccharides extracted from fungal organisms can be used both as nanoparticle carriers and sacrificial templates due to their highly functionalized structure. Although such carbohydrates

• on iron oxide and the polysaccharide S4, obtained from Lentinus Tigrinus (PS4). The most promising feature of such nanoentities based on iron oxide and polysaccharides is the bifunctional, oxidative [20] and acidic nature [21], which in turn can be fine-tuned to design highly active materials for

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

• -group-free; reductive amination; Findings Agarose (1) is the term utilized to describe a type of galactose-containing polysaccharides biosynthesized by certain species of algae belonging to the division Rhodophyta (red seaweeds). It is a linear biopolymer constituted of the disaccharide repeating unit

• available, these polysaccharides are far little explored as sources of chemical platforms for drug development. The rare monosaccharide 3,6-anhydro-α-L-galactopyranose (AnGal), naturally present in the agarose structure, is a valuable scaffold since it is a highly functionalized and a chiral-rich monomer

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• , Japan 10.3762/bjoc.13.116 Abstract A detailed electron spin resonance (ESR) analysis of mechanically induced free radicals (mechanoradicals) formation of glucose-based polysaccharides, dextran (Dx) and glycogen (Gly) was performed in comparison with amylose mechanoradicals. The ESR spectra of the

• formation have generally been conducted at low temperature (77 K) [2]. In previous papers we discussed the mechanoradical formation through mechanolysis of synthetic polymers [3][4] and polysaccharides such as amylose and cellulose [5] at room temperature under strictly anaerobic conditions. ESR spectral

• radicals. Great attention has been paid to graft polymerization of synthetic polymers onto polysaccharides, because this method easily produces a polymer combining the advantages of both natural and synthetic macromolecules [6]. A polysaccharide possessing functional group on its backbone that allows to

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

• of polysaccharides. Insights into the kinetics of catalytic events observed in the crystalline state are also presented as well as some aspects of structure determination of protein in solution. Keywords: antibodies; carbohydrate binding domains; cellulose; glycosaminoglycans; glycolipids; glycosyl

• hydrolases; glycosyl transferases; kinetic crystallography; lectins; polysaccharides; powder diffraction; small-angle X-ray scattering; starch; synchrotron radiation; transporters; X-ray crystallography; Introduction Over the last decade, glycoscience has greatly benefited from the development of structural

• to some key areas of glycoscience potentially of interest to the growing number of non-specialist users. Structural characterization of protein–carbohydrate interactions are covered as well as some involving glycolipids and colloids and the structure and architecture of polysaccharides. Insights into

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

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 1136–1138, doi:10.3762/bjoc.13.112

• Stephen Hill M. Carmen Galan School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, UK 10.3762/bjoc.13.112 Keywords: fluorescent carbon dots; monosaccharides; nanomaterials; nanotechnology applications; polysaccharides; Our original publication showns some errors in the

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

• GAuNPs are constituted by two main entities, the metallic core and the organic surface (i.e., mono- oligo- and polysaccharides). The features of these entities are tightly related to their application and effectiveness (Figure 2). Therefore, a careful design of GAuNP is required to obtain the best

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

• challenges. Keywords: fluorescent carbon dots; monosaccharides; nanomaterials; nanotechnology applications; polysaccharides; Introduction Nanotechnology applied to biological and biomedical problems has seen an explosion of research in recent years [1]. Functional nanomaterials that can carry biologically

• their differences allow tailoring of the CD structure and properties [25]. In this review, we focus on the most recent approaches developed to prepare fluorescent CDs using mono-, oligo- and polysaccharides as the main carbon source. Review Fluorescent carbon dots synthesised from monosaccharides

• , readily available neutral carbohydrate such as glucose as the carbon source in combination with a nitrogen-containing molecule. Glucosamine hydrochloride, which is a byproduct from the hydrolysis of chitosan and chitin polysaccharides found on crustacean shells, bears an amine functionality at C-2 and

Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

• Peter H. Seeberger,
• Claney L. Pereira and
• Subramanian Govindan

Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19

• polysaccharides (CPS) that surround them, are responsible for about 90% of infections worldwide [7]. The licensed polysaccharide vaccine Pneumovax 23 contains serotype 12F but is not efficacious in young children or elderly people, those at highest risk. The carbohydrate conjugate vaccines Prevanar13™ and

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• , polysaccharides serve also as structural components: cellulose for plants and chitin for arthropods. Moreover, saccharides and their derivatives play key roles in the immune system, fertilization, blood clotting, information transfer, etc. For instance, the 5-carbon monosaccharide ribose forms the backbone of the

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• glucose via biotechnological and chemocatalytic depolymerization of polysaccharides. The conversion of D-sorbitol into isosorbide via sorbitan is then usually performed by a twofold dehydration reaction using different types of catalysts (Scheme 1) [49][50][51][52][53][54][55][56][57][58][59][60]. In 1968

Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

• Eric Buchy,
• Branko Vukosavljevic,
• Maike Windbergs,
• Dunja Sobot,
• Camille Dejean,
• Simona Mura,
• Patrick Couvreur and
• Didier Desmaële

Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109

• of cells usually consist of spectral contributions from proteins, lipids and polysaccharides. For the simultaneous detection of both the drug and the cell components with the aim to investigate how they interact, a significant spectral contrast is required. Unfortunately, it can be hardly achieved

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• chain (OPS) called O antigen and capsular polysaccharide (K antigen) of Azospirillum, which is an extracellular form of LPS [8][9], are important for the interaction between bacteria and host plants. The cell-surface polysaccharides of Azospirillum are involved in overcoming of unfavorable conditions

• oligosaccharide, selective solvolysis with CF3CO2H was employed. Recently, this method has been successfully used for the structure elucidation of the O-specific polysaccharides of Escherichia coli (e.g. [20]). The reagent was found to cleave selectively the glycosidic linkage of 6-deoxyhexoses (Rha, Fuc