Synthesis and evaluation of a putative acyl tetramic acid intermediate in tenellin biosynthesis in Beauveria bassiana. A new role for tyrosine

✍ Scribed by M.Caragh Moore; Russell J Cox; Gordon R Duffin; David O'Hagan

• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 832 KB
• Volume: 54
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(98)00557-2

✦ Synopsis

The acyltetramic acid 6 previously proposed as a putative intermediate in tenellin biosynthesis in Beauveria bass/ana has been synthesised in two isotopically labelled forms. This compound was not incorporated into tenellin and was not identifiable in extracts of B. bass/ann and is unlikely to be involved in teneUin biosynthesis. On the other hand a re-evaluation of the role of tFrosine reveals that it is a good precursor to tenellin and is probably generated in vivo by the action of a phenylal=Lnine hydroxyluse directly from L-pbenylalanine. Thus the long held contention that acylteLramic acid 6 und=rgoos oxidative ring expansion to a pyridone no longer appears a valid hypothesis for tenellin biosynthesis.