Application of stable isotope labelling methodology to the biosynthesis of the mycotoxin, terretonin, by aspergillus terreus: incorporation of 13C-labelled acetates and methionine, 2H- and 13C, 18O-labelled ethyl 3,5-dimethylorsellinate and oxygen-18 gas
✍ Scribed by C.Rupert McIntyre; Fiona E. Scott; Thomas J. Simpson; Laird A. Trimble; John C. Vederas
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- French
- Weight
- 965 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
Incorporation of 13C-labelled acetates and methionine, 14C and ZH-labelled ethyl 3,5-dimethylorsellinate into terretonin (5) by cultures of Aspergillus terreus indicated that its biosynthesis proceeds via a mixed polyketide-terpenoid (meroterpenoid) pathway. Incorporation of 1803 gas and ethyl 3,5-dimethylorsellinate (7) doubly labelled with 13C and 180 in the carbonyl of the carboxyl group and at the C-6 position into terretonin (5) and observation of 180 isotope-induced shifts in the 13C n.m.r. spectra and SC/MS studies of the enriched metabolites determined the origin of all of the oxygen atoms in (5) and provided mechanistic insight into the biosynthetic pathway. Andibenin B (I)I, andilesin A (2)2 and anditomin (3)3 are members of a group of metabolites isolated from Aspergillus variecolor. Along with au&in (4) isolated from Aspergillus ustus,4 Penicillium diversum and Emericella dentata6 they form a group of metabolites which arise via a common pathway.