Synthesis and Recovery of N ‐Sulfo Heparosan From Fermentation Broth

Heparosan, a glycosaminoglycan (GAG) derived from bacterial capsular polysaccharide (CPS), shares a similar backbone with both clinically utilized heparin and heparan sulfate (HS). This facilitates its transformation into heparin/HS via chemoenzymatic strategies. Currently, the purification process of heparosan, followed by N ‐deacetylation and N ‐sulfation, requires executing several complex steps prone to the unintended loss of polysaccharides and environmental risks. In this study, heparosan extracted from fermentation broth underwent immediate N ‐deacetylation and N ‐sulfation before DEAE chromatography purification. The results showed that the recovery of N ‐deacetylated heparosan increased from less than 40% to 93.6% with negligible contaminants. After sulfation, the overall recovery yield of N ‐sulfo heparosan was 76.0%. The number average molecular weight (M n ) and weight average molecular weight (M W ) of N ‐sulfo heparosan were ascertained to be 5.2 and 10.7, respectively, with a polydispersity index (PDI) value of 2.1. The assessment of elemental composition revealed that the efficiency of N ‐sulfation was 84%, which aligns with that of commercial heparin. The strategy delineated in this investigation avoids the substantial loss of N ‐deacetylated polysaccharides resulting from the complex procedures. Furthermore, the study avoids using harmful organic solvents in preparing heparosan, thereby promoting the in vitro green synthesis of heparin‐like polysaccharides and analogous pharmaceutical compounds.