1963 年 83 巻 7 号 p. 671-673
Triterpenoid components were examined in the flowers of Pieris japonica (THUNBERG) D. DON, and β-amyrin, oleanolic acid, ursolic acid, and β-sitosterol were isolated and identified. In addition, a hitherto unknown neutral triterpenoid (C32H52O2, m. p. 188-189°) was isolated. Its infrared spectrum suggested the presence of endo-methylene group and the spectrum was similar to that of lupeol acetate except for the region of 1000-1100cm-1. It was therefore assumed that this new triterpenoid is its epimer with respect to its 3-hydroxyl group but no evidence has yet been obtained.