Evidence for an octanoate synthase operating during the biosynthesis of piliformic acid in Poronia piliformis
摘要:
Sodium [1-C-13]-octanoate is incorporated intact into the C-8 unit of piliformic acid 1 in Poronia piliformis whereas sodium [3-C-13]-decanoate 2 is incorporated into this unit only after prior beta-oxidation to [1-C-13]-acetyl-CoA. Also 8-fluoraoctanaote 3 is utilised by P. piliformis as an intact unit to generate 9-fluoropiliformic acid 5 whereas 10-fluorodecanoate 4 is not. These results suggest that octanoate is biosynthesised de novo for secondary metabolism and is not assimilated from higher fatty acids by beta-oxidation. (C) 1998 Elsevier Science Ltd. All rights reserved.
experiments with (2)H- and (13)C-labeled decanoic acid, their 3-oxygenated congeners, and octanoicacid have suggested that 1 is biosynthesized via coupling of a C(5) unit with octanoate, rather than via introduction of a C(3) unit at the alpha position of a decanoate derivative. Further feeding study of [2,3-(13)C(2)]decanoic acid concluded that the former route is operating in the biosynthesis of 1.