Biomedical Engineering Reference
In-Depth Information
Figure 2. Molecular structures of fatty acids used for the synthesis of acyl ascorbate.
1. Optimal Conditions for Enzymatic Synthesis
of Acyl Ascorbate in a Batch Reaction
The condensation of L-ascorbic acid and lauric acid was carried out in dehydrated
acetonitrile using various lipases from different origins, such as Chirazyme
®
L-2 C2 from
Candida antarctica
(Roche Molecular Biochemicals, Germany), which was the same as
Novozym
®
435 (Novo Nordisk Bioindustry Japan, Japan) and immobilized on a macroporous
acrylic resin, lipases PS from
Pseudomonas cepacia
, A from
Aspergillus niger
, F from
Rhizopus oryzae
and M from
Mucor javanicus
(Amano Enzyme, Japan), lipases PL and QL
from
Alcaligenes
sp
.
, AL from
Achrobacter
sp., OF from
Candida cylindracea
and MY from
C. cylindracea nov.
sp. (Meito Sangyo, Japan), lipase type VII from
C. cylindracea
(Sigma
Chemical, USA), to find the lipase which could catalyze the condensation in the medium
[24]. Acetonitrile was dehydrated by adding molecular sieves 5A at a concentration of 0.2
g/mL-solvent. Twenty milliliters of the dehydrated solvent, 1 mmol of ascorbic acid and 5
mmol of a fatty acid were put into a glass vial with a screw-cap, then 400 mg of lipase was
added. The vial was tightly sealed and immersed in a water-bath. The condensation reaction
