Chemical Derivatization of Sulfated Glycosaminoglycans

Abstract

Sulfated glycosaminoglycans (GAGs) are a family of complex polysaccharides ubiquitously distributed in extracellular matrices and at cell surfaces and playing key roles in a myriad of biological processes. Their structures are based on disaccharide building blocks, usually containing an amino sugar and an uronic acid, decorated with one or more sulfate groups. Many efforts to gain access to a large number of sulfated GAG polysaccharides with potential tailored biomedical applications, usually based on suitable chemical (and chemo-enzymatic) derivatization procedures that modified the native polysaccharide structures, have been reported in the last two decades. In this review we survey such reactions on the basis of (i) the sulfated GAG substrate [(fucosylated) chondroitin sulfate, dermatan sulfate, heparin, and heparan sulfate], and (ii) the sort of structural modification (sulfation pattern modification, oxidation, carboxy group derivatization, N- and O-acylation, reducing-end functionalization)

Chemical composition of isoprene SOA under acidic and non-acidic conditions: effect of relative humidity

“…Silylation of polar compounds results in reduced polarity, enhanced volatility, and increased thermal stability, and they enable the GC-MS analysis of many compounds otherwise involatile or too unstable for these techniques. Therefore, appropriate caution should be taken, for example, with desulfation reactions associated with primary organosulfates (Takano et al, 1992;Kolender et al, 2004;Bedini et al, 2016Bedini et al, , 2017Cui et al, 2018), and corrections might be warranted when analyzing methyltetrols.…”

“…-The presence of the abundant m/z 97 peak corresponding to the HSO − 4 ion indicates that the hydrogen atom is present at the carbon atom next to that bearing HO-SO 2 -O-moiety (Attygalle et al, 2001). There are, however, exceptions seen in Figs.…”

“…The SO 2 levels at Zielonka were approximately 0.6 and 3.0 µg m −3 at Godów. At each site, organic carbon / elemental carbon ratio (OC/EC) values was determined for each filter using a thermo-optical method (Birch and Cary, 1996). The organic carbon value at Zielonka was approximately 1.7 and 5.4 µg m −3 at Godów, although aerosol masses were not determined.…”

A Study for the Access to a Semi-synthetic Regioisomer of Natural Fucosylated Chondroitin Sulfate with Fucosyl Branches on N-acetyl-Galactosamine Units

“…Firstly, the Bn protecting groups on putative Fuc branches were oxidatively cleaved with NaBrO 3 and Na 2 S 2 O 3 in a H 2 O/ethyl acetate mixture [50] to give derivatives 13-i-iv with three free hydroxyls on Fuc branches. The liberated alcohol moieties were then sulfated together with the residual non-fucosylated GalNAc sites under standard conditions with the SO 3 ·pyridine complex in DMF at 50 • C [51]. Finally, alkaline hydrolysis of the ester protecting groups, followed by purification of the polysaccharides by dialysis and filtration on a C-18-silica reverse phase plug, furnished semi-synthetic fCS-i-iv in 50-58% weight yield (over five steps, calculated from 5; see Table 1).…”

Decoration of Chondroitin Polysaccharide with Threonine: Synthesis, Conformational Study, and Ice-Recrystallization Inhibition Activity

“…Many other pharmacological and biomedical applications are currently under development,4 with a particular focus on the field of drug delivery and tissue engineering. In the last two decades many works appearing in the literature have reported chemical and chemo-enzymatic derivatization of CS or unsulfated chondroitin, aiming to access modified polysaccharide structure with tailored biomedical applications 5–10. Among the derivatization reactions, carboxyl group modification with amines or hydrazides is very common.…”