Eudistomin K: crystal structure and absolute stereochemistry

✍ Scribed by Robin J. Lake; John D. McCombs; John W. Blunt; Murray H.G. Munro; Ward T. Robinson

• Publisher: Elsevier Science
• Year: 1988
• Tongue: French
• Weight: 214 KB
• Volume: 29
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)80655-3

✦ Synopsis

The crystal structure of a derivative of the antiviral and antitumour compound eudistomin K la has been determined, confirming the proposed structure and stereochemistry. The conformation found for the oxathiazepine ring in the solid state is similar to that proposed for the solution state from nmr spectroscopic measurements.

The oxathiazepine eudistomins, first reported from the Caribbean ascidian Eudistoma olivaceuml la-d, and more recently from the New Zealand ascidian Ritterella sigillinoides2 la-b,e, are tryptophan derivatives of considerable synthetic and biological interest. These eudistomins are distinguished by the unusual structural combination of N, 0, C and S, and as a group display potent antiviral and antitumour activity 1 p2. The original structure determination of this new class of alkaloid was based on nmr and mass spectrometric evidence', and supported by a subsequent, extensive nmr spectroscopic study2.

We now report the crystal structure and confirm the absolute stereochemistry of the p-bromobenzoyl derivative of eudistomin K 1 h (Figure ).