title: Fungicidal sesquiterpene dialdehyde cinnamates from Pseudowintera axillaris.
abstract: Bioactivity-directed separation of a foliage extract from the New Zealand shrub Pseudowintera axillaris led to a compound with fungicidal activity against the plant pathogen Phytophthora infestans. This was identified as a new sesquiterpene dialdehyde cinnamate named paxidal. Two 6-hydroxy derivatives were present at lower levels in the extract. A further nine derivatives were synthesized from these natural products for a structure-activity study against a range of important food crop pathogens. The cinnamate group was important for fungicidal effects, and protection of the dialdehyde as a dimethyl acetal gave more potent, broader spectrum activity.
authors.affiliation: New Zealand Institute for Crop and Food Research Ltd., Department of Chemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.
authors.forename: Nerida J
authors.initials: NJ
authors.lastname: Brennan
authors.forename: Lesley
authors.initials: L
authors.lastname: Larsen
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Lorimer
authors.forename: Nigel B
authors.initials: NB
authors.lastname: Perry
authors.forename: Eleanor L
authors.initials: EL
authors.lastname: Chapin
authors.forename: Todd L
authors.initials: TL
authors.lastname: Werk
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Henry
authors.forename: Donald R
authors.initials: DR
authors.lastname: Hahn
mesh_terms: D002934:Cinnamates / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D005659:Fungicides, Industrial / Q000032:analysis* / Q000494:pharmacology; D008958:Models, Molecular; D009520:New Zealand; D010838:Phytophthora / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D032425:Pseudowintera / Q000737:chemistry*; D012717:Sesquiterpenes / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D002934:Cinnamates; D005659:Fungicides, Industrial; D010936:Plant Extracts; D012717:Sesquiterpenes; C508956:paxidal