NMR structural elucidation of channaine, an unusual alkaloid from Sceletium tortuosum. (February 2018)

• Record Type: Journal Article
• Authors: Veale, Clinton G.L.; Chen, Weiyang; Chaudhary, Sushil; Kituyi, Sarah N.; Isaacs, Michelle; Hoppe, Heinrich; Edkins, Adrienne L.; Combrinck, Sandra; Mehari, Bewketu; Viljoen, Alvaro
• Is Part Of: Phytochemistry letters. Volume 23(2018)
• Page Start: 189
• Page End: 193
• Publication Date: 2018-02
• Subjects: Channaine -- Sceletium -- Alkaloids; Botanical chemistry -- Periodicals; Chimie végétale -- Périodiques; 572.205
• DOI: 10.1016/j.phytol.2017.11.018
• Languages: English
• ISSNs: 1874-3900

Abstract

Graphical abstract: Highlights: This work details the first full NMR structural elucidation of channaine. This is also the first reported identification of channaine since 1978. Our extraction and purification method as well as our NMR data may assist in future identification of channaine. Abstract: Chemical interrogation of the Sceletium genus and Amaryllidaceae family of plants has yielded a diverse array of aryl-hydroindole containing alkaloids. Included in this class is channaine, which was tentatively identified, without comprehensive structural elucidation from Sceletium tortuosum in 1957. Following its isolation from S. strictum, the structure of channaine was eventually resolved by X-ray crystallographic analysis, which revealed an unusual cage-like ring structure at the interface of two aryl-hydroindole subunits. However, since this report in 1978, channaine has not re-appeared in the literature. In this letter, the full NMR characterisation of channaine, isolated from S. tortuosum collected from St Helena in the Western Cape Province of South Africa, is reported for the first time.