Studies on the biosynthesis of the antibiotic moenomycin A

Feeding experiments (C-13 and N-15-labeled precursors) shed light on the biosynthetic origin of the chromophore (unit A of 1), the N-acetyl groups, the 4-C-methyl group of the moenuronamide unit (part F of 1), the sugar units. and the lipid part (unit 1 of 1) of the antibiotic moenomycin A (1). The lipid part is completely isoprenoid and is constructed via the non-mevalonate pathway. The central Clo part originates from a precursor like geranyl or linalyl diphosphate and is formed by a route involving ring formation between C-2 and C-6 of the monoterpene unit, two successive rearrangements to give a 7-membered ring intermediate and cleavage of the ring between C-5 and C-11 (moenocinol numbering).