Chemical glycobiology

• Elisa Fadda,
• Rachel Hevey,
• Benjamin Schumann and
• Ulrika Westerlind

Beilstein J. Org. Chem. 2025, 21, 8–9, doi:10.3762/bjoc.21.2

• glycan assembly [9]. Target-directed synthetic strategies are being developed by Reihill et al. [10] and Karak et al. [11], exploring the syntheses of the linker-displaying, sulfated TF disaccharide and lipid II analogues, respectively. The direct application of synthetic glycans is shown by Fan et al

• methods to make the glycosciences even more palatable to generalists. And we see a field that innovates. This thematic issue seeks to highlight the amazing breadth of contemporary chemical glycobiology. Dal Colle et al. investigate the determinants that influence the oligosaccharide yield in automated

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• Universität Berlin, Arnimallee 22, 14195 Berlin, Germany 10.3762/bjoc.19.77 Abstract Automated glycan assembly (AGA) affords collections of well-defined glycans in a short amount of time. We systematically analyzed how parameters connected to the solid support affect the AGA outcome for three different

• purification steps. Keywords: automated glycan assembly; photocleavable linker; polysaccharides; solid-phase synthesis; Introduction Automated glycan assembly (AGA) is a solid-phase method that enables the rapid synthesis of complex oligo- and polysaccharides from protected monosaccharide building blocks

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

• approach (also known as fragment coupling) allows connecting pre-assembled oligosaccharide blocks. To decrease the synthetic time required for the chemical synthesis of polysaccharides, automated techniques have been developed [28][29][30][31]. Automated glycan assembly (AGA) connects monosaccharide BBs on

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

• 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

• after each glycosylation and further optimized reaction conditions allowed for the synthesis of a series of oligosaccharides, ranging from hexa- to branched dodecasaccharides. Keywords: arabinomannan; automated glycan assembly; capping; Introduction Bacterial infections caused by MTB killed 1.7

• Mai Hoang for the proofreading of the manuscript. This work used Dr. Bharate’s thesis “Automated Glycan Assembly of Oligomannose Glycans for Sensing Applications” as a source.

1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides

• Fei-Fei Xu,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2017, 13, 1994–1998, doi:10.3762/bjoc.13.195

• trimethylsilyl trifluoromethanesulfonate (TMSOTf) were employed as co-promoters in solution or automated glycan assembly on solid phase. Keywords: automated glycan assembly; 1,3-dibromo-5,5-dimethylhydantoin; glycosylation; promoter; thioglycosides; Introduction Thioglycosides are versatile glycosylating

• donors [3][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, most of those activators are expensive and toxic [5][17][19]. Poor solubility complicates the use of some promoters during automated glycan assembly [20][21][22][23], while the instability of some activators in solution requires them to

• acetonitrile [45] was used as co-solvent. With all these donors, the α-stereoselectivity increased at higher temperature [46]. Donor 13, containing a remote participating group, produced the disaccharide with better α-selectivity [22][42]. Automated glycan assembly is the most rapid means to access complex

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

• participation groups and solvent effects. It lends further credence to the linear assembly concept in which one monosaccharide unit at a time is incorporated, and which serves as the basis for automated glycan assembly [43]. With the synthetically sourced hexasaccharide repeating unit in hand detailed

Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

• Markus W. Weishaupt,
• Stefan Matthies,
• Mattan Hurevich,
• Claney L. Pereira,
• Heung Sik Hahm and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2016, 12, 1440–1446, doi:10.3762/bjoc.12.139

• variability. Herein, we report the first iterative automated glycan assembly (AGA) of a conjugation-ready S. pneumoniae serotype 3 CPS trisaccharide. This oligosaccharide was assembled using a novel glucuronic acid building block to circumvent the need for a late-stage oxidation. The introduction of a washing

• ]. Automated glycan assembly builds on monomeric building blocks that are incorporated during iterative glycosylations [28][29]. Here, a set of building blocks was identified that can be employed interchangeably in the automated syntheses of a wide variety of biologically relevant glycans. To minimize the post

• using Pd(OH)2/C in methanol/water/acetic acid (50:25:1 v/v/v) afforded the fully deprotected S. pneumoniae serotype 3 CPS antigen 11 in 71% yield over three steps (Scheme 5). Conclusion The first automated glycan assembly of a conjugation-ready S. pneumoniae serotype 3 trisaccharide 11 using glucuronic

Automated solid-phase synthesis of oligosaccharides containing sialic acids

• Chian-Hui Lai,
• Heung Sik Hahm,
• Chien-Fu Liang and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2015, 11, 617–621, doi:10.3762/bjoc.11.69

• carbohydrate antigens (TACAs) such as the sialyl-Tn antigen (sTn) [2]. Neu5Ac is often the terminal residue and is usually linked via an α-(2,3) or α-(2,6) linkage to galactose (Gal) (Figure 1) [3]. Automated glycan assembly enables rapid access to structurally defined oligosaccharides [4][5] including

• incorporation of sialic acid–galactose disaccharide building blocks [5][11]. Here, we describe a sialic acid building block that can be utilized for automated glycan assembly. Results and Discussion Sialylating oligosaccharides in high yield and α-selectivity was challenging since the presence of a C-1 carboxyl

• these considerations sialyl phosphate building blocks 4 and 5 [14] were selected for automated glycan assembly using monosaccharides (Scheme 1). The synthesis of building block 4 commenced with the placement of a C-9 Fmoc protecting group on thioglycoside 1 [14] to produce 2. Installation of O