19132-81-1Relevant academic research and scientific papers
Differentiation- and apoptosis-inducing activities by pentacyclic triterpenes on a mouse melanoma cell line
Hata, Keishi,Hori, Kazuyuki,Takahashi, Saori
, p. 645 - 648 (2007/10/03)
In a study to investigate the relationship between the chemical structure and the differentiation-inducing activity of pentacyclic triterpenes, several lupane, oleanane, and ursane triterpenes were prepared and their effects on B16 2F2 melanoma cell differentiation and growth were examined. Eleven lupane triterpenes used in this study acted on the melanoma cells as a melanogen, but no induction of melanogenesis of B16 2F2 cells by oleanane and ursane was detected. The differences at C-17 of the lupane series and acetylation of the OH group at C-3 did not markedly influence their activities. However, the ED50 value for up-regulation of melanin biosynthesis was markedly decreased by the oxidation of the OH group at C-3 of lupeol (1). Betulinic acid (11), its methyl ester (12), lup-28-al-20(29)-ene-3β-ol (9), and lup-28-al-20(29)-en-3-one (10) inhibited B16 2F2 cell proliferation by induction of apoptosis. These findings suggested that the carbonyl group at C-17 might be essential for the apoptotic effects of these compounds on B16 2F2 cells.
Triterpenoids of the Bark of Pieris japonica D. Don (Japenese Name: Asebi). II. 13C Nuclear Magnetic Resonance of the γ-Lactones of Ursane- and Oleane-type Triterpenes
Katai, Masaaki,Terai, Tadamasa,Meguri, Haruo
, p. 1567 - 1571 (2007/10/02)
Eight triterpenoids and a sterol were isolated from the bark of Pieris japonica D.Don (Japenese name: asebi, Ericaceae) and have been elucidated as 3β-acetoxyurs-11-en-28,13-olide, 3β-acetoxy-12α-hydroxyolean-28,13-olide, 3β-acetoxy-28-hydroxyurs-12-ene, 3β,28-dihydroxyurs-12-ene, 3β-acetoxyurs-12-en-28-al, taraxeryl-acetate, taraxerol, taraxerone and β-sitosterone by a combination of chemical and spectroscopic studies. 13C Nuclear magnetic resonance spectral analysis of several γ-lactones of the ursane and oleanane series was undertaken, and all the carbons were assigned by means of single frequency off-resonance and selective decoupling methods and by comparison of the signals with those of methyl esters of acetyl ursolic acid and acetyl oleanolic acid.Keywords - Pieris japonica; bark; triterpenoid; ursane-type γ-lactone; oleanane-type γ-lactone; 1H-NMR; 13C-NMR
