5. ANTIBIOSIS AND ANTIBIOTICS
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aromatic precursor, possibly gentisaldehyde, which undergoes a ring
cleavage followed by lactonization (CXXXIV).
O^OH
Biosynthesis of patulin
(CXXXIV)
The biosynthesis of many antibiotics seems to involve some kind of
coupling of two or more phenolic units.
A first type of such coupling is seen in griseofulvin (CXXXV), an
antifungal compound produced by several species of Penicillium and by
Carpentes brefeldianum, in its natural analogs bromogriseofulvin and
OCH.
Griseofulvin
(CXXXV)
OH
dZ-Erdin (R = COOH) and
rf-geodin (R = COOCH 3
)
(CXXXVI)
dechlorogriseofulvin, and in the very similar and closely related compounds, d-geodin and d,Z-erdin (CXXXVI) from A. terreus
(287-289a).