Synthetic derivatives of the α- and β-amyrin triterpenes and their antinociceptive properties Original Research Article

Fifteen different derivatives of an α- and β-amyrin mixture were synthesized by acylation with appropriate anhydride or acid chlorides and oxidation in the presence of tert-butyl chromate or PCC. The molecular structures of the obtained compounds were confirmed by means of IR and 1H NMR spectra. The compounds were screened for antinociceptive activity using the acetic acid pain model. The 3-O-acyl derivatives α- and β-amyrin propionate 4, α- and β-amyrin hexanoate 6, and α- and β-amyrin octanoate 7 were found to be the most active compounds of the series. In addition, we also have found that α- and β-amyrin octanoate 7 was able to reduce acetic acid-induced abdominal constriction when administered by oral route. Furthermore, this compound reduced the nociceptive response induced by intraplantar injection of formalin.