Study On Enzymatic Synthesis Of 2-O-β-Glucopyranosyl-L-Ascorbid Acid

In this paper,a new method for the determination of 2-o-β-Glucopyranosyl-L-ascorbid acid by Reversed Phase High Performance Liquid Chromatography(HPLC) with was established.The samples were analyzed on a 5μm Zorbax SB-Aq column with diode array detection at 254 nm, under the following conditions:mobile phase,0.08%trifluoroacetic acid; flow rate,1.0 mL/min;column temperature,30℃;the injection volume was 20μL.2-o-β-glucopyranosyl-L-ascorbid was isolated from the dried fruit of Lycium barbarum,a plant of the Solanaceae family by Fast Protein Liquid Chromatography(FPLC),under the following conditions:HiPrep ^TM16/10 Q XL column;mobile phase,5%acetic acid solution;flow rate,5.0 mL/min;detection wavelength,280 nm;the injection volume was:10 mL。A Trichoderma.viride had been screened,which synthesizes glucopyranosyl-transferase.DPPH radical scavenging test approved that the free radical scavenging capacity of AA-2βG in reaction liquid last longer than L-AA.The optimal medium for glucopyranosyl- transferase synthesis was:15.0%straw powder,5.0%bran,0.4%(NH₄)₂SO₄,0.012% MgSO₄,1×CMC tween-40,10 mL water.The optimal fermentation condition:32℃,4 d.The optimal synthesis condition:40 mg/mL cellobiose,40mg/mL ascorbic acid,16mg/mL enzyme,acetate buffer(pH 5),stirred at 37℃for 24 h.The enzyme activity of FPA,CMC and C1 in 4 cellulase were compared.The enzyme activity of C1 in Yaulk cellulase and self-made cellulose were higher than other 2 two kind cellulase.The enzyme activity of glucopyranosyl- transferase is determined by C1.