Dirigent proteins from cotton (Gossypium sp.) for the Atropselective synthesis of gossypol.

Publication Type

Journal contribution (peer reviewed)

Authors

Effenberger, I., Zhang, B., Li, L., Wang, Q., Liu, Y., Klaiber, I., Pfannstiel, J., Wang, Q., Schaller, A.

Year of publication

2015

Published in

Angew. Chem. Int. Ed. Engl.

Band/Volume

54/49

DOI

10.1002/anie.201507543

Page (from - to)

14660-3

Gossypol is a defense compound in cotton plants for protection against pests and pathogens. Gossypol biosynthesis involves the oxidative coupling of hemigossypol and results in two atropisomers due to hindered rotation around the central binaphthyl bond. (+)-gossypol predominates in vivo, suggesting stereochemically controlled biosynthesis. We aimed to identify the factors mediating (+)-gossypol formation in cotton and to investigate their potential for asymmetric biaryl synthesis. A dirigent protein from Gossypium hirsutum (GhDIR4) was found to confer atropselectivity to the coupling of hemigossypol in presence of laccase and O₂ as oxidizing agent. (+)-gossypol was obtained in > 80 % enantiomeric excess as compared to racemic gossypol in absence of GhDIR4. The identification of GhDIR4 highlights a broader role for DIRs in plant secondary metabolism and may eventually lead to the development of DIRs as tools for the synthesis of axially chiral binaphthyls.