Alstonia scholaris: Struktur des Indolalkaloides Narelin

✍ Scribed by Yutaka Morita; Manfred Hesse; Hans Schmid; Avijit Banerji; (Mrs.) Julie Banerji; (Mrs.) Asima Chatterjee; Willi E. Oberhänsli

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: German
• Weight: 1018 KB
• Volume: 60
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19770600434

✦ Synopsis

Alstonia scholaris: The structure of the indole alkaloid nareline

Besides the known akuammidine, picralinal, picrinine and pseudoakuammigine a new indole alkaloid called nareline (M=352) was isolated from Alstonia scholaris R. BR., which belongs to the plant family of Apocynaceae. Its structure 2 was deduced by single crystal X‐ray diffraction. 2 represents the absolute configuration. The spectroscopic data of 2 and its derivatives (Scheme 1) as well as their chemical behavior support this structure. In biogenetic sense nareline is related to the bases akuammiline (4) and picraline (5) (Scheme 2). In contrast to those the C‐atom 5 is exocyclic and represents an aldehyde group which forms together with the oxygen atom of the N (4)‐hydroxylamine group a cyclic half acetale. ‐ By oxidation (CrO~3~/CH~3~COOH) of 2 the oxindol derivative 19 (oxonareline) is formed which contains a cyclic acetal as a partial structure element (Scheme 4).