1 邦産オモト(Rhodea japonica Roth.)根茎および東部ヒマラヤ産Campylandra aurantiaca根茎のステロイド成分

抄録

In connection with a study on the structures of two steroidal compounds, BR-1(XIII) and BR-2(XIV), which were isolated from the rhizomes of an east Himalayan plant Campylandra aurantiaca, an extensive survey for the steroidal constituents of the rhizomes of domestic Rhodea japonica Roth. has been carried out in this laboratory. To date, more than twenty kinds of compounds were obtained, and fourteen of them were characterized. This study concerns the structure elucidations of additional four compounds, R-1(I), R-2(II), R-16(III) and R-23(IV), of R. japonica, and identification of BR-1(XIII) and BR-2(XIV) with I and II, respectively. The structure of I(=XIII) was determined on the basis of chemical and spectral data and unequivocally confirmed by X-ray analysis. III was also assigned the detailed structure with the aid of X-ray crystallography, while II(=XIV) and IV were characterized respectively by correlation with I and III. I(=XIII) and II(XIV) are noted as the spirostane derivatives highly oxygenated in the rings A and B, and III and IV, are, to our knowledge, the first cardenolide glycosides having D-allose attached to the aglycone. It is also worth of note that the C-ring of the aglycone (bipindogenin) of III has the boat conformation.