The microbiological production of analogues of mould metabolites. Part 2. Production of 9α-fluorogibberellin A4, 9α-fluorogibberellin A14, and other fluoroterpenoids by Gibberella fujikuroi

Abstract

ent-15β-Fluorokaur-16-en-19-oic acid (3) has been prepared from xylopic acid and fed to fermentations of Gibberella fujikuroi in the presence of AMO-1618. The products have been shown to include 9α-fluorogibberellin A₄(28), 9α-fluorogibberellin A₁₄(17), 15α-fluorofujenal (23), 15α-fluoro-7β-hydroxykaurenolide (18), a metabolite which may be 15α-fluoro-1β,7β-dihydroxykaurenolide (21), and 1α-carboxy-2β-hydroxy-1β,4aα-dimethyl-8-methylenegibbane-10β,9α-carbolactone (25). In the absence of AMO-1618 ent-15β-fluorokaur-16-en-19-ol had no detectable effect upon a fermentation of G. fujikuroi.