Study on the Synthesis of Uncommon Sugar of L-galactose and Its Derivatives

OBJECTIVE L-galactose and its intermediate D-galacturonic acid and L-galactonic acid-1,4-lactones were prepared and optimized. METHODS D-galacturonic acid was prepared by enzymatic hydrolysis of pectin, and the best enzymatic hydrolysis technology was established by orthogonal experimental design. L-galactonic acid-1,4-lactones was synthesized from D-galacturonic acid via reduction and dehydration, L-galactose was synthesized from L-galactonic acid-1,4-lactones via reduction. RESULTS The optimum conditions for enzymatic hydrolysis were as follow:hydrolysis temperature was 50℃, The reaction time was 2 h, the enzyme-pectin ratio was 1.5:10. The structure of products were characterized by ¹H-NMR and ¹³C-NMR. The yield was 31.4%. CONCLUSION The method is simple and convenient, with short steps and high yield. It can be applied to industrial production.