Journalartikel

Jahr der Veröffentlichung: 2015

Seiten: 15-21

Zeitschrift: Journal of Molecular Catalysis B: Enzymatic

Bandnummer: 121

ISSN: 1381-1177

DOI Link: https://doi.org/10.1016/j.molcatb.2015.07.008

Verlag: Elsevier

Abstract: 
The edible fungus Pleurotus sapidus (PSA) is a particularly interesting biocatalytic system for allylic oxidation and has a remarkably broad substrate range from terpenoids to fatty acids. The oxidations are most likely catalyzed by a lipoxygenase and involve the formation of peroxides via radical intermediates in the first rate-limiting step. We provide herein a rationalization of the observed regioselectivity of these conversions by means of computational determination of bond dissociation enthalpies of a set of tailor-made spirocyclic terpenoids. It was found that only strongly activated allylic positions (BDH298 of <80 kcal/mol) with neighboring heteroatoms or with activating alkyl groups are oxidized to the corresponding unsaturated lactones or enones, respectively. With the synthesis and purification of allylic hydroperoxide intermediates, we have been able to characterize the putative direct precursors of enones in PSA oxidations. Our results suggest a two-step oxidation mechanism involving hydroperoxide intermediates which are rapidly converted to the observed enones by an enzymatic reaction.

Harvard-Zitierstil: Weidmann, V., Kliewer, S., Sick, M., Bycinskij, S., Kleczka, M., Rehbein, J., et al. (2015) Studies towards the synthetic applicability of biocatalytic allylic oxidations with the lyophilisate of Pleurotus sapidus, Journal of Molecular Catalysis B: Enzymatic, 121, pp. 15-21. https://doi.org/10.1016/j.molcatb.2015.07.008

APA-Zitierstil: Weidmann, V., Kliewer, S., Sick, M., Bycinskij, S., Kleczka, M., Rehbein, J., Griesbeck, A., Zorn, H., & Maison, W. (2015). Studies towards the synthetic applicability of biocatalytic allylic oxidations with the lyophilisate of Pleurotus sapidus. Journal of Molecular Catalysis B: Enzymatic. 121, 15-21. https://doi.org/10.1016/j.molcatb.2015.07.008