title: Structure--activity relationships in the fungistatic activity against Botrytis cinerea of clovanes modified on ring C.
abstract: The preparation of clovanes 4, 5, 6, 8, and 9, which bear different levels of oxidation on ring C, is described for the first time. The biotransformation of compounds 5, 6, and 9 by the fungus Botrytis cinerea is investigated, yielding compounds 10, 11, and 12, which are described for the first time, together with compounds 4-6, 8, and 9. The evaluation of the fungistatic activity against B. cinerea of compounds 6, 9, 12, 18, 19, 20, and 21 is reported. Comparison of these results with previously published data shows first that the inclusion of hydroxyl groups on ring C leads to a decrease in the biological activity and, second, that the presence of a 9alpha-hydroxyl group and an alkyl chain at C-2 plays an important role in the fungistatic activity against B. cinerea of compounds with a clovane skeleton.
authors.affiliation: The School of Chemistry, Physics and Environmental Science, University of Sussex, Brighton, Sussex, BN1 9QJ, United Kingdom.
authors.forename: Athina
authors.initials: A
authors.lastname: Deligeorgopoulou
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Macías-Sánchez
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Mobbs
authors.forename: Peter B
authors.initials: PB
authors.lastname: Hitchcock
authors.forename: James R
authors.initials: JR
authors.lastname: Hanson
authors.forename: Isidro G
authors.initials: IG
authors.lastname: Collado
mesh_terms: D001711:Biotransformation; D020171:Botrytis / Q000187:drug effects*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D003500:Cyclization; D005659:Fungicides, Industrial / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010935:Plant Diseases / Q000382:microbiology*; D013329:Structure-Activity Relationship
chemical_list: D001643:Bridged Bicyclo Compounds; D005659:Fungicides, Industrial