Preparations of Betulinic Acid Derivatives
Betulinic acid, 3~hydroxy-lup20(29)-ene-28-oic acid is a pentacyclic triterpene. Esterification reactions of betulinic acid were investigated. Betulinic acid esters such as 3-0-succinyl-betulinic acid, 3-0-(2',2'-dimethylsucciny1)-betulinic acid, 3-0-(3',3'-dimethylsucciny1)-b...
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Format: | Thesis |
Language: | English English |
Published: |
2004
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Subjects: | |
Online Access: | http://psasir.upm.edu.my/id/eprint/7080/1/FSAS_2004_5%28a%29.pdf http://psasir.upm.edu.my/id/eprint/7080/ |
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Summary: | Betulinic acid, 3~hydroxy-lup20(29)-ene-28-oic acid is a pentacyclic triterpene.
Esterification reactions of betulinic acid were investigated. Betulinic acid
esters such as 3-0-succinyl-betulinic acid, 3-0-(2',2'-dimethylsucciny1)-betulinic
acid, 3-0-(3',3'-dimethylsucciny1)-betulinic acid and 3-0-glutaryl-betulinic acid
were prepared. Their structures were determined by spectroscopic methods.
Optimization studies on the esterification reactions were carried out for
betulinic acid with succinic anhydride and with 2',2'-dimethylsuccinic acid
only. The effects of varying parameters such as the mole ratio, temperature, time
course and mole of catalyst were investigated.
Generally, the optimal conditions for preparing 3-0-succinyl-betulinic acid was
obtained by mixing betulinic acid with succinic anhydride in a 1:8 ratio and
refluxing in 0.124 mole of pyridine for 24 hours at a temperature of 115°C ; the
optimal conditions for the preparation of 3-0-(2',2'-dimethylsucciny1)-betulinic acid was obtained by refluxing betulinic acid and Zf,2'-dimethylsuccinic acid in
a 1:6 ratio with the presence of 0.124 mole of pyridine for 24 hours at a
temperature of 85°C. The percentage conversions as detected by gas
chromatography analysis were 53.5 and 56.2%, respectively. |
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