反应详情

To a pH 7.0˜7.5 solution of N-acetylmannosamine (2.7 g, 12.2 mmole) and sodium pyruvate (2.7 g, 24.5 mmole) in water (15 ml) was added a dialysis bag (cut off MW of 20,000) containing N-acetylneuraminate lyase [EC 4.1.3.3] (25 units) in a reaction mixture of N-acetylmannosamine (0.54 g) and sodium pyruvate (0.54 g) in water (3 ml) at pH 7.0-7.5. The reaction mixture was shaken at 60 r.p.m. at 30° C. for 5 days. The enzyme bag was removed and reused for new batch of reaction. The reaction mixture was diluted with water (15 ml), then passed through a column of Amberlite IRA-400 (HCOO− form) (150 ml). The resin was then washed with water (300 ml), eluted with 0.5M HCOOH solution. The eluate was collected and vacuum evaporated to dryness. The residue was dissolved in water (2 ml) then diluted with glacial acetic acid (10 ml) at 4° C. overnight, filtered the crystals, washed with EtOH, dried to afford N-acetylneuraminic acid as white crystalline powder (1.5 g, 39.8%).

1. customThe enzyme bag was removed
2. customreused for new batch of reaction
3. washThe resin was then washed with water (300 ml)
4. washeluted with 0.5M HCOOH solution
5. customThe eluate was collected
6. customvacuum evaporated to dryness
7. dissolutionThe residue was dissolved in water (2 ml)
8. additionthen diluted with glacial acetic acid (10 ml) at 4° C. overnight
9. filtrationfiltered the crystals
10. washwashed with EtOH
11. customdried