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|Section2= |Section7= }} Betulinic acid is a naturally occurring pentacyclic triterpenoid which has antiretroviral, antimalarial, 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''), selfheal (''Prunella vulgaris''), 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 (''Pseudocydonia sinensis'', former ''Chaenomeles sinensis KOEHNE''),〔 (''Chaenomeles sinensis KOEHNE'' is now named ''Pseudocydonia sinensis'')〕 rosemary, and ''Pulsatilla chinensis''. ==Antitumor activity== In 1995, betulinic acid was reported as a selective inhibitor of human melanoma. Then it was demonstrated to induce apoptosis in human neuroblastoma ''in vitro'' and ''in vivo'' in model systems. At one time, it was undergoing drug development with assistance from the Rapid Access to Intervention Development program of the National Cancer Institute.〔 Also, betulinic acid was found active ''in vitro'' against neuroectodermal (neuroblastoma, medulloblastoma, Ewing's sarcoma) and malignant brain tumors,〔 ovarian carcinoma,〔 in human leukemia HL-60 cells,〔 and malignant head and neck squamous cell carcinoma SCC25 and SCC9 cell lines. In contrast, epithelial tumors, such as breast, colon, small cell lung and renal cell carcinomas, as well as T-cell leukemia cells, were completely unresponsive to treatment with betulinic acid.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Betulinic acid」の詳細全文を読む スポンサード リンク
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