Industrial Biotransformations

d-Sorbitol dehydrogenase
Gluconobacter oxydans
1) Reaction conditions
[1]: 1 M (molecular weight depends on protecting group)
pH: 5.0
T: 32 °C
medium: aqueous
reaction type: oxidation
catalyst: suspended whole cells
enzyme: d-sorbitol:(acceptor)1-oxidoreductase (d-sorbitol dehydrogenase)
strain: Gluconobacter oxydans
CAS (enzyme): [9028–22–2]
2) Remarks
HO
1
NHR’
OH
OH
OH
OH
EC 1.1.99.21
● The published synthesis of 1-desoxynojirimycin and its derivatives requires multiple steps and
a laborious protecting group chemistry.
● To prevent undesired follow up reactions of 6-amino-d-sorbose in water the amino group has
to be protected by, e.g., a benzyloxycarbonyl group. The protection of 1-amino-d-sorbitol is carried
out in an aqueous medium at pH 8–10 with benzyloxycarbonyl chloride.
● The cells of Gluconobacter oxydans are produced by fermentation on sorbitol and used for the
bioconversion step, which is carried out in water without added nutrients.
● The cells are not immobilized; the very high specific substrate conversion rate would lead to
severe limitations in immobilization beads.
● 6-Amino-l-sorbose (N-protected) is used as an intermediate in the manufacture of miglitol via
1-desoxynojirimycin. 1-Desoxynojirimycin is produced by chemical intramolecular reductive
amination of 6-amino-l-sorbose. Miglitol is used in the treatment of Type 2 (non-insulin
dependent) diabetes.
HO
2
NHR’
OH
1 = 1-amino-D-sorbitol (N-protected)
2 = 6-amino-L-sorbose (N-protected) Bayer AG
Fig. 1.1.99.21 – 1
182
E
- H2
OH
O
OH