Novel alkaloids, paxdaphnines A and B with unprecedented skeletons from the seeds of Daphniphyllum paxianum |
| |
Authors: | Cheng-Qi Fan |
| |
Institution: | State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 555 Zuchongzhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China |
| |
Abstract: | Two novel Daphniphyllum alkaloids with unprecedented skeletons, namely paxdaphnines A (1) and B (2), have been isolated from the seeds of Daphniphyllum paxianum. Paxdaphnine A (1) is a 19-nor-Daphniphyllum alkaloid with highly caged skeleton, and paxdaphnine B (2) is the first 1,19-bisnor-Daphniphyllum alkaloid. The relative structures of 1 and 2 were elucidated by spectral methods, and their unique biosynthetic pathway postulated. The absolute structure of 1 was determined by X-ray diffraction of the iodide derivative (1a) of 1, and the absolute stereochemistry of 2 was proposed by correlation with the biosynthetic pathway for 1. |
| |
Keywords: | Paxdaphnines A and B Daphniphyllum alkaloids Absolute stereochemistry X-ray diffraction Biosynthetic pathway |
本文献已被 ScienceDirect 等数据库收录! |
|