New Clean Processes For Extraction Of Pentosan And Preparation Of Its Derivatives

With the continuous consumption of petrochemical resources,the utilization of renewable resources has received more and more attention.Biomass resources are one of the most abundant renewable resources on the earth today.However,at present,biomass resources have not been fully and effectively utilized.Therefore,the fine and efficient use of biomass resources has practical and long-term significance for the sustainable development of human beings.Wheat bran is the by-products of in wheat processing,which is rich in hemicelluloses(pentosan)with excellent chemical and biological activity,pentosan is an important food additive component,and its chemically modified products have various Physiological activities,at present,abundant wheat bran in China is used to produce feed with low added value.It is of great practical significance to develop the clean processes to to extract pentosan from wheat bran and the preparation its derivatives.This paper first developed a new process for the efficient extraction of pentosan from wheat bran by hydrothermal method.The effect of hydrothermal temperature,extraction time,solid-liquid ratio on target product yield and product molecular weight were investigated.The optimal extraction parameters were as follows:hydrothermal temperature150 ~oC,hydrothermal time 15 h,solid-liquid ratio 1:10 The yield of t pentosan was 27.5%,and the molecular weight was 60675.The method has the advantages of high product yield,simple process operation,no use of aggressive harmful reagents,and the process is clean and pollution-free.Anticoagulant drugs can effectively inhibit thrombotic diseases,and the preparation of heparin,one of the mostly used anticoagulant drugs,is derived from animal organs,and is of high cost in raw materials and biorejectivity.Since pentosan sulfate has a similar chemical structure and anticoagulant activity with heparin,the development of new plant-derived pentosan sulfates has become a key topic in the field.For the first time,the synthesis of pentosan sulfate from pentosan and sulfamic acid was carried out by mechachemistry method.The effect of the mass ratio of pentosan to sulfamic acid,the rotation speed of ball mill and the milling time on the degree of sulfuric acid substitution(DS)and pentosansulphate yield were studied.The suitable process parameters for the reaction were determined as:the mass ratio of pentosan to sulfamic acid was 1:2,the rotation speed of the ball mill was 650 rpm,and the milling time was 12 h.Under this condition,the target product yield was 189.9%,and the DS was 1.714..The product was identified as the target product by FT-IR,NMR analysis.