- 著者
-
北川 勲
石津 隆
大橋 一慶
澁谷 博孝
- 出版者
- 公益社団法人 日本薬学会
- 雑誌
- YAKUGAKU ZASSHI (ISSN:00316903)
- 巻号頁・発行日
- vol.120, no.10, pp.1017-1023, 2000-10-01 (Released:2008-05-30)
- 参考文献数
- 20
- 被引用文献数
-
6
9
Monthly changes of the content-ratio between S-(-)-and R-(+)-hyoscyamine as well as those between S-(-)-and R-(+)-scopolamine in the leaves of Datura metel L. cultivated in the field, were quantitatively analyzed by the use of HPLC with a chiral adsorbent. It was found that S-(-)-isomer was predominant for hyoscyamine and the ratio of R-(+)-isomer gradually increased during the growth, whereas in the case of scopolamine, S-(-)-isomer was the sole one found throughout the cultivation period. The 1H-NMR study in the CD3OD solution has suggested that S-(-)-hyoscyamine (1) and S-(-)-scopolamine (2) take a "face-to-face"conformation between their tropane skeletons and the benzene rings of the tropic acid moieties. In the presence of an equimolar NaOD in the CD3OD solution, the racemization at C-2' of 1 and 2 proceeded more rapidly than the hydrolysis at the tropic acid ester bond, presumably due to the steric hindrance caused by their"face-to-face"conformations. In the D2O and H2O solutions, on the other hand, the racemization and the hydrolysis of 1 proceeded smoothly, while those of 2 did not occur. It has been supposed that these individual reaction manners are ascribable in considerable extent to the different basicity of N atom in each tropane skeleton of 1 and 2 and to stronger intramolecular hydrogen bond occurring between the carbonyl oxygen at C-1' and the hydroxyl group at C-3' in the tropic acid moiety of 1.