Eudistomidin G, a new β-carboline alkaloid from the Okinawan marine tunicate Eudistoma glaucus and structure revision of eudistomidin B

✍ Scribed by Yohei Takahashi; Haruaki Ishiyama; Takaaki Kubota; Jun’ichi Kobayashi

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 306 KB
• Volume: 20
• Category: Article
• ISSN: 0960-894X
• DOI: 10.1016/j.bmcl.2010.05.071

✦ Synopsis

A new b-carboline alkaloid, eudistomidin G (1), has been isolated from the Okinawan marine tunicate Eudistoma glaucus, and the structure was elucidated from spectroscopic data. Furthermore, the structure of eudistomidin B (2), which has been isolated from the same tunicate, was revised from 2a to 2b by detailed analyses of spectroscopic data. Asymmetric synthesis of the revised structure (2b) of eudistomidin B (2) and its (1S,10S)-diastereomer (2c) has been accomplished with the Noyori catalytic asymmetric hydrogen-transfer reaction. The absolute configuration of eudistomidin B (2) was confirmed to be 2b possessing (1R,10S)-configuration, from comparison of the 1 H NMR data, CD spectra, [a] D values, and HPLC analysis of 2b, 2c, and natural eudistomidin B.