反应 #446832

ord-518a169bf99e48148ef9f6922b57e577

反应方程式

O=C[C@H](O)[C@@H](O)[C@@H](O)[C@H](O)CO
D-galactose
O=C=O
CO2
O=C[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO
glucose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose
→
O=C(CO)[C@@H](O)[C@@H](O)[C@H](O)CO
tagatose

反应物

O=C[C@H](O)[C@@H](O)[C@@H](O)[C@H](O)CO
D-galactose
O=C=O
CO2
O=C[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO
glucose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose
OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O
lactose

试剂

无

溶剂

O
water

反应条件

温度
50°CELSIUS
详细条件
See reaction.notes.procedure_details.

后处理

  1. 1
    workup.ADDITIONtreated with 80 mg lactase 30,000
  2. 2
    workup.ADDITIONadded
  3. 3
    温度The mixture was heated to 75° C. briefly
  4. 4
    过滤was then filtered
  5. 5
    温度was heated to 70° C
  6. 6
    过滤had been filtered
  7. 7
    其他degassed
  8. 8
    workup.WAITThe run time was approx. 55 minutes
  9. 9
    其他The filtered reaction mixture
  10. 10
    浓缩described above was concentrated to 30% by weight solids
  11. 11
    其他the mixture was separated into two groups of fractions
  12. 12
    浓缩The second group of fractions was concentrated to 10% by weight solids for the isomerization step
  13. 13
    workup.ADDITIONwas treated with 2.0 g calcium hydroxide and 0.15 g calcium chloride
  14. 14
    其他the precipitate formed within 1.5 hours

实验过程

A 100 ml flask containing 10.0 g lactose and 50 ml water was warmed to 50° C. and treated with 80 mg lactase 30,000 enzyme as in Example 3. After 6 hours the solution was analyzed by HPLC and found to contain 10% lactose, 45% D glucose, and 45% D-galactose, based on the lactose added. The mixture was heated to 75° C. briefly to denature the protein, and was then filtered. A 2.5 cm interior diameter by 60 cm length glass column was packed with about 300 ml of BIO-RAD AG 50W-X8 resin in the calcium form, minus 400 mesh. BIO-RAD AG 50W-X8 is the trademark for a cationic ion exchange resin sold by Bio-Rad, Richmond CA. The column was heated to 70° C. The mobile phase was deionized water which had been filtered and degassed and which was pumped at a flow rate of 4.0 ml per minute. Typical pressure was 30 psig. The sample injection loop was 10 ml. The run time was approx. 55 minutes. The filtered reaction mixture described above was concentrated to 30% by weight solids, then injected in portions into the column. By using a refractive index detector to monitor the eluant, the mixture was separated into two groups of fractions. The combined first group of fractions contained 0.8 g of lactose and 4. 2 g D-glucose. The combined second group of fractions contained 0.3 g of D-glucose and 4.4 g of D-galactose. The second group of fractions was concentrated to 10% by weight solids for the isomerization step. The D-galactose solution, stirred at room temperature in a small flask, was treated with 2.0 g calcium hydroxide and 0.15 g calcium chloride, and the precipitate formed within 1.5 hours. The precipitate of calcium hydroxide - tagatose complex was neutralized with CO2 to give 2.2 g D - tagatose.

来源

DOI: 10.6084/m9.figshare.5104873.v1专利: US05002612uspto-grants-1991_03