Screening of Neu5Acα(2–6)gal isomer preferences of siglecs with a sialic acid microarray

Abstract

Sialic acids (Sias) are important terminal sugars on cell surfaces involved in a wide range of protein-carbohydrate interactions. Hence, agents modulating sias-mediated protein interactions are promising inhibitors or vaccine candidates. Here, we report the synthesis of Neu5Acα(2-6)Gal structural analogs and their binding to a series of siglecs. The results showed distinct binding patterns with conserved siglecs (hCD22 and mCD22) compared to rapid evolving siglecs (Siglecs -3 & -10).

Synthesis and Azobenzene Isomerization Investigation of Photoswitchable Glycomacrocycles

“…Esterification of 3 with methyl 2,3-di- O -benzyl-α-D-glucopyranoside 4 furnished the desired 6- O -esterified compound 5 (41%), along with the 4- O -esterified compound 6 (15%) and the 4,6-di- O -esterified one 7 (17%) (Scheme ). Azide function was then introduced on the 6-position of phenyl 2,3,4-tri- O -benzyl-α-D-thiomannopyranoside 8 to 9 through mesylate intermediate or to 10 through reaction with chloroacetyl chloride, followed by the S N 2 reaction with NaN 3 (Scheme ). The CuAAC reaction of 9 or 10 with the propargyl derivative 5 led, respectively, to the glycosyl donor–acceptor pairs 11 and 12 in 85–86% yield as pure E -isomers.…”

“…To a solution of 8 (201.8 mg, 0.372 mmol) and Et 3 N (205 μL, 1.475 mmol) in CH 2 Cl 2 (15 mL) at 0 °C was added chloroacetyl chloride (60 μL, 0.738 mmol). The mixture was stirred for 2 h at 0 °C and at rt overnight.…”

“…Phenyl 6-Azide-2,3,4-tri-O-benzyl-6-deoxy-1-thio-α-Dmannopyranoside (9). To a solution of 8 32 (1.12 g, 2.06 mmol) and Et 3 N (580 μL, 4.1 mmol) in CH 2 Cl 2 (18 mL) was added MsCl (260 μL, 3.3 mmol) at 0 °C. The solution was stirred for 20 h at rt before addition of methanol (280 μL).…”

ABO Antigens Active Tri- and Disaccharides Microarray to Evaluate C-type Lectin Receptor Binding Preferences

“…In contrast, the assembly of 3 (O-antigen, Fucα(1-2)GalβPEGNH 2 ) and 4 (Fucα(1-3)GlcNAcβPEGNH 2 ) involved the assembly of thiofucoside donor 10 and reducing end sugar 4,6-benzilidine-galactoside 12a and glucosamine acceptor 14 , respectively. The thiogalactoside building block 7 and thiofucoside donor 10 were synthesized as previously described 19 – 22 . The donor 8 was synthesized from a known thiogalactoside donor 15 , which was synthesized from D-galactose in 4 steps, as described 22 .…”

“…The thiogalactoside building block 7 and thiofucoside donor 10 were synthesized as previously described 19 – 22 . The donor 8 was synthesized from a known thiogalactoside donor 15 , which was synthesized from D-galactose in 4 steps, as described 22 . Benzylation of the C-2 and C-3 hydroxyl function of 15 provided the desired thiogalactoside building block 8 ( Fig.…”