Flow synthesis, characterization, anticoagulant activity of xylan sulfate from sugarcane bagasse.

High-value utilization of hemicellulose is critical to improve the append value of integrated biorefineries. In this research, the alkali-soluble sugarcane bagasse hemicellulose was sulfated using chlorosulfonic acid and N,N-dimethylformamide/LiCl under homogeneous conditions. With the aid of flow technique, a rapid, mild, and efficient method for the synthesis of xylan sulfate with high molecular weight and controllable degree of substitution was achieved. The results showed that the reaction time and the degradation of xylan chain were drastically reduced compared to the "in flask" batch conditions. High molecular weight of the product (M = 148,217) with a reasonable degree of substitution (DS = 1.49) could be obtained even at room temperature in 10 min under the present flow system. Anticoagulant experiments showed good anticoagulant activity of the resultant xylan sulfate, which could significantly prolong the activated partial thromboplastin time and thrombin time. This work not only provides a novel method for the synthesis of xylan sulfate, but also offers new opportunities for the production of other functional polysaccharide derivatives under the flow reaction conditions.