0000000000262541
AUTHOR
Mohammed Nour
New ursolic and betulinic derivatives as potential cytotoxic agents.
Fifteen new ursolic and betulinic triterpenoids, bearing various functionalities at C-3 and C-28 were synthesized as potential cytotoxic agents. All compounds were obtained by a hemisynthetic route via ursolic and betulinic acids. Preliminary screening of these compounds on human HT 29 colon cancer cells revealed inhibitory activity for three of them. Beta-D-Glucopyranosyl-3beta-hydroxyurs-12(13)-en-28-oate 1c, 3beta-3-(3-pyridyl)-prop-2-enoyloxyurs-12(13)-en-28-oic acid 1i and the potassium salt of 3beta-cinnamoyloxylup-20(29)-en-28-oic acid 2d demonstrated cytotoxic activity in the micromolar range: 8.0, 45.0 and 8.0 microM, respectively.
Lymphatic absorption of phytosterol oxides in rats
Two of the main classes of oxyphytosterols (7-keto and epoxides) were synthesized from sitosterol and campesterol and given to mesenteric duct-cannulated adult male rats. Lymph was collected during 24 h and was analyzed for oxysterols. The results showed that the lymphatic recovery of the phytosterol oxides was low: 4.7% of the given dose for epoxy derivatives and 1.5% for 7-keto compounds. The campesterol oxides presented a better absorption than the sitosterol oxides. During the process of absorption, the epoxyphytostanols were also partly transformed in campestanetriol and stigmastanetriol.
A review of natural and modified betulinic, ursolic and echinocystic acid derivatives as potential antitumor and anti-HIV agents.
The aim of this review is to update current knowledge on the betulinic, ursolic and echinocystic acids and their natural and semisynthetic analogs, focussing on their cytotoxic and anti-HIV activities. Then, the last results of the authors' team on unusual semisynthetic derivatives of these triterpenoids will be presented in order to establish structure/activity relationships.