1) The structure of theasapogenol E, one of seeds sapogenols of Thea sinensis L. has been established as 3β, 16α, 21β, 22α, 28-pentahydroxy-23-oxo-olean-12-ene (III). In conjunction with the study on alcoholic alkaline treatment of theasapogenol E leading the isomerization and/or the Meerwein-Ponndorf type reduction of the aldehyde function of III, it has been suggested that camelliagenin D (X) might be an artefact sapogenol. 2) The other two minor seeds sapogenols designated as theasapogenols D and C have been revealed identical with dihydropriverogenin A (=camelliagenin A)(IV) and camelliagenin C (V) respectively. Furthermore, the evidence supporting 22α-hydroxy (equatorial) of dihydropriverogenin A (IV) has been presented, which has led the revision of the previous structures of dihydropriverogenin A (e), priverogenin A (h) and priverogenin B (i). 3) On the basis of NMR examination, the conformation of some acetonide derivatives of dihydropriverogenin A (IV), barringtogenol C (I), and theasapogenol A (II) has been discussed.
No takes yet. Share an insight, caveat, or question.
Yosioka et al. (1971) studied this question.