Construction of a library of fully protected oligosaccharide for preparing various subtypes of chondroitin sulfate

Chondroitin sulfate (CS) regulates a wide range of biological processes, including cell differentiation and division, cancer development, and viral infections. We herein explored and established the method to se-lectively remove the 4,6-benzyl protective group of galactosamine, selectively introduced different types of protecting groups at positions 4 and 6, and synthesized four different subtypes of CS oligosaccharide modules-CS-O, A, C, and E-and a small library of 16 fully protected tetrasaccharides with different sub-types of CS disaccharides, which could be converted into the final corresponding CS product according to the literature. This work will be helpful for the research of structure-activity relationship and pharmaco-logical mechanism of CS in the future and unlocking the "sulfation code." & COPY; 2023 Elsevier Ltd. All rights reserved.