Enzymatic Preparation of Aucubigenin and Its Stability

Aucubigenin was prepared from aucubin by β-glucosidase hydrolysis. The single water and n-butanol-water two-phase enzymatic hydrolysis conditions of aucubigenin were optimized bysingle factor experiment. The main factors that affected the stability of aucubigenin were investigated.The results showed that the optimum conditions of single-phase enzymatic hydrolysis were temperature 35℃, time 20 min, enzyme dosage 25 U/mL, and the yield of aucubigenin reached 46.3%. Through screening, the n-butanol-water two-phase reaction system was constructed. The optimum conditions of two-phase enzymatic hydrolysis were n-butanol volume fraction 80%, temperature 35℃, enzyme dosage 25 U/mL, time 20 min, and the yield of aglycone reached 87.9%.Aucubigenin had poor thermal stability, and it was relatively stable in 12 h at-20 and 0℃; it was easy to decompose under neutral and alkaline conditions, and was most stable at pH 3.0, only 12% degraded in 8 h; the stability of the aqueous solution of aucubigenin with 5 g/L V_C was significantly improved, only 8% degraded within 2 h; aucubigenin was very stable in n-butanol and hardly degraded in 8 h.