Page 122 - phytochemistry I - PharmD Clinical
P. 122
Natural "vanilla extract" is prepared from vanilla pods. Artificial vanilla
flavoring is often a solution of pure vanillin, usually of synthetic origin.
Because of the scarcity and expense of natural vanilla extract, synthetic
preparation of its predominant component has long been of interest.
Methods for preparing vanillin:
1. From coniferin
Coniferin glycoside is hydrolysed to coniferyl alcohol with the loss
of a glucose molecule. Then coniferyl coniferyl alcohol is oxidized
to give vanillin.
2. From eugenol:
Eugenol constitues about 95% of clove oil, which is treated with an
alkali at high temperature to be converted to isoeugenol. Then
vanillin is produced through oxidation of isoeugenol.
3. From lignin
Lignins are phenolic polymers found in plant cell walls, which are
responsible, with cellulose, for the stiffness and rigidity of plant
stems.. Lignin undergoes catalytic oxidation to form vanillin.
۱۲۰
