title: Hydroxylation of Longiborneol by a Clm2-Encoded CYP450 Monooxygenase to Produce Culmorin in Fusarium graminearum.
abstract: A second structural gene required for culmorin biosynthesis in the plant pathogen Fusarium graminearum is described. Clm2 encodes a regio- and stereoselective cytochrome P450 monooxygenase for C-11 of longiborneol (1). Clm2 gene disruptants were grown in liquid culture and assessed for culmorin production via HPLC-evaporative light scattering detection. The analysis indicated a complete loss of culmorin (2) from the liquid culture of the ΔClm2 mutants. Culmorin production resumed in a ΔClm2 complementation experiment. A detailed analysis of the secondary metabolites extracted from the large-scale liquid culture of disruptant ΔClm2D20 revealed five new natural products: 3-hydroxylongiborneol (3), 5-hydroxylongiborneol (4), 12-hydroxylongiborneol (5), 15-hydroxylongiborneol (6), and 11-epi-acetylculmorin (7). The structures of the new compounds were elucidated by a combination of HRMS, 1D and 2D NMR, and X-ray crystallography.
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Adilah
authors.initials: A
authors.lastname: Bahadoor
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Danielle
authors.initials: D
authors.lastname: Schneiderman
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Larissa
authors.initials: L
authors.lastname: Gemmill
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Whynn
authors.initials: W
authors.lastname: Bosnich
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Barbara
authors.initials: B
authors.lastname: Blackwell
authors.affiliation: Measurement Science and Standards, National Research Council Canada , Ottawa, ON K1A 0R6 Canada.
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Melanson
authors.affiliation: Measurement Science and Standards, National Research Council Canada , Ottawa, ON K1A 0R6 Canada.
authors.forename: Garnet
authors.initials: G
authors.lastname: McRae
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada , Ottawa, ON K1A 0C6 Canada.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Harris
mesh_terms: D018360:Crystallography, X-Ray; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D006900:Hydroxylation; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D012717:Sesquiterpenes / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D012717:Sesquiterpenes; C013900:culmorin; C412581:longiborneol; D003577:Cytochrome P-450 Enzyme System