Abstract
The structure of theasapogenol A, one of seeds sapogenols of Thea sinensis L. has been established as 3β, 16α, 21β, 22α, 23, 28-hexahydroxy-olean-12-ene (II), and some additional investigations on the oxide ring formation between C-21 and C-16 of barringtogenol C (I) and II have been summarized. In addition, the evidence concerning to the anisotropic effect caused by the trityl function has been presented.