白桦脂酸

Betulinic acid is found in abiyuch. Betulinic acid is a naturally occurring pentacyclic triterpenoid which has anti-retroviral, anti-malarial, and anti-inflammatory properties, as well as a more recently discovered potential as an anticancer agent, by inhibition of topoisomerase. It is found in the bark of several species of plants, principally the white birch (Betula pubescens) from which it gets its name, but also the Ber tree (Ziziphus mauritiana), the tropical carnivorous plants Triphyophyllum peltatum and Ancistrocladus heyneanus, Diospyros leucomelas a member of the persimmon family, Tetracera boiviniana, the jambul (Syzygium formosanum), flowering quince (Chaenomeles sinensis), Rosemary, and Pulsatilla chinensis. Controversial is a role of p53 in betulinic acid-induced apoptosis. Fulda suggested p53-independent mechanism of the apoptosis, basing on fact of no accumulation of wild-type p53 detected upon treatment with the betulinic acid, whereas wild-type p53 protein strongly increased after treatment with doxorubicin. The suggestion is supported by study of Raisova. On the other hand Rieber suggested that betulinic acid exerts its inhibitory effect on human metastatic melanoma partly by increasing p53.