TY - JOUR

T1 - Chemical and Genetic Studies on the Formation of Pyrrolones During the Biosynthesis of Cytochalasans

AU - Zhang, Haili

AU - Hantke, Verena

AU - Bruhnke, Pia

AU - Skellam, Elizabeth J.

AU - Cox, Russell J.

N1 - Funding Information: The authors would like to thank Dr. Jennifer Senkler and Prof. Dr. Hans-Peter Braun from the Institute of Plant Genetics, Leibniz University of Hanover for protein sequence analysis by ESI Q-TOF. Inken Hertrampf (LUH) and Franck Siacku (LUH) are thanked for technical assistance. DFG is thanked for the provision of NMR and LCMS equipment (INST 187/621-1, INST 187/686-1). V.H. was funded by DFG (CO 1328/2-1) and H.Z. was funded by the China Scholarship Council (CSC 201506200065). Open access funding enabled and organized by Projekt DEAL.

PY - 2021/2/10

Y1 - 2021/2/10

N2 - A key step during the biosynthesis of cytochalasans is a proposed Knoevenagel condensation to form the pyrrolone core, enabling the subsequent 4+2 cycloaddition reaction that results in the characteristic octahydroisoindolone motif of all cytochalasans. In this work, we investigate the role of the highly conserved α,β-hydrolase enzymes PyiE and ORFZ during the biosynthesis of pyrichalasin H and the ACE1 metabolite, respectively, using gene knockout and complementation techniques. Using synthetic aldehyde models we demonstrate that the Knoevenagel condensation proceeds spontaneously but results in the 1,3-dihydro-2H-pyrrol-2-one tautomer, rather than the required 1,5-dihydro-2H-pyrrol-2-one tautomer. Taken together our results suggest that the α,β-hydrolase enzymes are essential for first ring cyclisation, but the precise nature of the intermediates remains to be determined.

AB - A key step during the biosynthesis of cytochalasans is a proposed Knoevenagel condensation to form the pyrrolone core, enabling the subsequent 4+2 cycloaddition reaction that results in the characteristic octahydroisoindolone motif of all cytochalasans. In this work, we investigate the role of the highly conserved α,β-hydrolase enzymes PyiE and ORFZ during the biosynthesis of pyrichalasin H and the ACE1 metabolite, respectively, using gene knockout and complementation techniques. Using synthetic aldehyde models we demonstrate that the Knoevenagel condensation proceeds spontaneously but results in the 1,3-dihydro-2H-pyrrol-2-one tautomer, rather than the required 1,5-dihydro-2H-pyrrol-2-one tautomer. Taken together our results suggest that the α,β-hydrolase enzymes are essential for first ring cyclisation, but the precise nature of the intermediates remains to be determined.

KW - Knoevenagel

KW - biosynthesis

KW - cytochalasan

KW - hydrolase

KW - pyrrolone

UR - http://www.scopus.com/inward/record.url?scp=85099392305&partnerID=8YFLogxK

U2 - 10.1002/chem.202004444

DO - 10.1002/chem.202004444

M3 - Article

VL - 27

SP - 3106

EP - 3113

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 9

ER -