Enhanced absorption of digitoxin from orally administered digitoxin-polyvinylpyrrolidone coprecipitates
✍ Scribed by Elliot I. Stupak; Theodore R. Bates
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 465 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
alanine(Xll1, S:<). A chemical method was developed for the separation of the amino acid VIll from the phenolic products present in the hydrolysis mixture.
- Under basic conditions. hydrolysis of the acetamidomalonate ester IX gave low yields (5-7yJ of the required amino acid VIII.
However, no phenolic side-products were formed under this condition.
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Synthesis of the formamidomalonate ester XVI and its hydrolysis under basic conditions were carried out in an effort to realize higher yields of triniethoxyphenylalariine (VIII). The hydrolysis of the ester XVI also gave unsatisfactory yields of the target amino acid V11I.
-
An eficient alternative synthesis of trimethoxyphenylalanine (VIII) was achieved which involves the formation of the hydantoin derivative XXllI and its hydrolysis under basic conditions (66 yield).
-
GCmass spectrometric examination of the peyote amino acid fraction gave no evidence for the presence of trioxygenated phenylalanine analogs, VllI and XI-XIII. This observation suggests that the carboxyl group may not survive beyond the stage of dopa during the biosynthesis of the trioxygenated peyote alkaloids.