The Bioconversion of (3 RS,E )‐ and (3 RS,Z )‐Nerolidol into Oxygenated Products by Streptomyces cinnamonensis . Possible Implications for the Biosynthesis of the Polyether Antibiotic Monensin A??

The ability of the monensin‐producing organism Streptomyces cinnamonensis to bioconvert the ( E )‐and ( Z )‐isomers of nerolidol (= 3,7,1 1‐trimethyldodeca‐1,6,10‐trien‐3‐ol) into new oxygenated products has been investigated. When a 3 H‐labelled racemic form of each sesquiterpene was added to fermentations of S. cinnamonensis , several new 3 H‐labelled products could be detected. Two products were isolated from bioconversion of ( E )‐nerolidol, the amide 8 and the 9 ( Scheme 2 ), whereas four products were isolated from the bioconversion of ( Z )‐nerolidol, the epoxydiol 10 , triols 11 and 12 , and the tetrahydrofuryl alcohol 13 ( Scheme 4 ). Products 9 – 13 were obtained as a 1 : 1 mixture of diastereoisomers, and 12 was shown to arise by the overall anti addition of two OH groups to the trisubstituted ( Z )‐double bond of ( Z )‐nerolidol. Both isomers of nerolidol as well as the acetylene 7 are inhibitors of monensin production in shake cultures of S. cinnamonensis .