One-Pot Assembly of the Highly Branched Tetradecasaccharide from Ganoderma lucidum Glycan GLSWA-1 with Immune-Enhancing Activities

Abstract

The highly branched tetradecasaccharide repeating unit and shorter sequences of GLSWA-1 with immune-enhancing activities from Ganoderma lucidum have been prepared via a one-pot glycan assembly strategy. The synthetic route features (1) orthogonal one-pot glycosylation on the basis of PVB glycosylation to streamline glycan synthesis avoiding such issues as aglycone transfer, (2) one-pot assembly of oligosaccharides with up to four different glycosyl linkages, and (3) modular and convergent [4+5+5] one-pot assembly of the highly branched tetradecasaccharide.

One-Pot Assembly of Mannose-Capped Lipoarabinomannan Motifs up to 101-Mer from the Mycobacterium tuberculosis Cell Wall

“…Due to issues of regioselectivities and stereoselectivities during glycan assembly, traditional carbohydrate syntheses often involve a stepwise process, which is laborious and time-consuming. The one-pot glycan assembly strategy has merits such as acceleration of synthesis, no requirement of intermediate purification during the glycosylation interval, and reduction of chemical wastes, thereby highly streamlining carbohydrate synthesis. − Herein, we report the first total synthesis of mannose-capped LAM 101-mer 1 from the Mtb cell wall via the orthogonal one-pot assembly strategy on the basis of glycosyl ortho -(1-phenylvinyl)­benzoates (PVB), which precludes such issues as aglycone transfer inherent to one-pot glycosylation with thioglycosides (Scheme ). Short sequences 2 – 4 are also prepared for in-depth biological studies to better understand the structure–activity relationship.…”

Total Synthesis of Nona-decasaccharide Motif from Ganoderma sinense Polysaccharide Enabled by Modular and One-Pot Stereoselective Glycosylation Strategy

“…While traditional synthesis of glycans is a stepwise and laborious process, one-pot glycans synthesis is a streamlined process and has the following advantages: (1) no need of intermediates purification during glycosylation interval; (2) acceleration of glycans synthesis; and (3) reduction of chemical waste. , Here, we report the first chemical synthesis of nona-decasaccharide 1 from G. sinense polysaccharide GSPB70-S through modular and one-pot glycosylation strategy on the basis of glycosyl ortho -(1-phenyvinyl)­benzoates (PVB), which not only speeds up carbohydrates synthesis but also avoids potential issues, such as aglycone transfer inherent to one-pot glycosylation based on thioglycosides. , Shorter sequences 2 – 4 were also prepared for SAR biological studies. The following features are highlighted in our synthetic approach: (1) N -methyl- N -phenylformamide (MPF)-modulated preactivation-based one-pot 1,2- cis -glycosylation for highly stereoselective assembly of continuous α- d -GlcN-(1 → 4) and α- d -Gal-(1 → 4) glycosidic linkages, as well as two contiguous α- d -GlcN-(1 → 4) bonds; (2) several orthogonal one-pot glycosylations to streamline diverse linear and branched glycans synthesis on the combinations of glycosyl N -phenyltrifluoroacetimidates (PTFAI), glycosyl ortho -alkynylbenzoates (ABz), and glycosyl PVB; and (3) [1 × 4 + 15] Yu glycosylation for the final efficient assembly of long, highly branched, and complex nona-decasaccharide 1 .…”