Biosynthesis and biotechnological production of aliphatic gamma- and delta-lactones

Albrecht, W.; Heidlas, J.; Schwarz, M.; Tressl, R.

Biosynthesis and biotechnological production of aliphatic gamma- and delta-lactones

1992

Albrecht, W. | Heidlas, J. | Schwarz, M. | Tressl, R.

The enantiomeric composition of gamma- and delta-lactones isolated from peaches was determined. Post-harvest ripening of the fruits was characterized by an increase in the concentration of lactones. The configuration and the optical purity both remained constant. Biosynthetic studies on gamma- and delta-lactones were performed with the lactone producing yeast Sporobolomyces odorus. After administration of [9,10,12,13-2H4]-linoleic acid to intact cells of Sp. odorus, deuterium labelled (Z)-6-dodecen-4-olide, gamma-nonalactone, and delta-decalactone could be detected. The conversion of (S)-13-hydroxy-(Z,E)-9,11-octadecadienoic acid into optically pure (R)-delta-decalactone was elucidated. Based on the results of incubation experiments with deuterium labelled hydroxy- and oxo acids, an oxidation of the secondary hydroxy group followed by a subsequent enantioselective reduction was found to be responsible for the inversion of configuration. Administered [2,2-2H2]-(E)-3-decenoic acid and [2,2-2H2]-(E)-3,4-epoxydecanoic acid were converted into deuterium labelled gamma-decalactone. Based on the abstraction of one 2H atom in the course of the biotransformations and the identification of labelled 2-decen-4-olide, a biosynthetic pathway leading to gamma-decalactone is presented. The biotechnological production of optically pure (R)-gamma-decalactone and (R)-(Z)-7-decen-4-olide from ricineloic acid and densipolic acid, respectively, is presented. With chemically modified and deuterium labelled precursors mechanistic and stereochemical features are depicted.

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