糖尿病是一种代谢性疾病，如果不进行治疗，将导致各种疾病。目前，全球糖尿病患者高达4.15亿人，预计到2040年将增加10%。番石榴多糖是番石榴果实起到治疗糖尿病的重要的活性物质。2007年，具有alpha-葡萄糖苷酶抑制活性的多糖GB90-1B从番石榴的果实中被分离提取和结构表征。然而，从自然界中分离提取纯的和足够量的多糖GB90-1B非常困难，大大阻碍了对其进行深入的生理活性研究。此项目通过化学合成番石榴多糖GB90-1B十九糖重复单元和相应的子结构，并对其进行深入的生理活性和构效关系研究。此项目对开发治疗糖尿病番石榴多糖药物具有十分重要的意义！

Diabetes is a metabolic disease, which if not treated properly, results in serious complications. This disease affects over 415 million people globally, which is estimated to increase by 10% by 2040. Psidium guajava polysaccharide is the major active ingredient of Psidium guajava fruit for the treatment of diabetes. In 2007, polysaccharide GB90-1B with high alpha-glucosidase inhibitory activity was isolated and characterized from Psidium guajava fruit. However, the extremely difficult isolation of pure and sufficient amount of polysaccharide GB90-1B has retarded in-depth studies of their biological activities. This project aims to chemical synthesis and biological studies of GB90-1B nonadecasaccharide repeating unit and substructures. This project is very meaningful for the development of therapeutic carbohydrate drugs for treatment of diabetes.