title: Isolation of nematicidal compounds from Tagetes patula L. yellow flowers: structure-activity relationship studies against cyst nematode Heterodera zeae infective stage larvae.
abstract: Bioassay-guided isolation studies on the extracts of yellow flowers of Tagetes patula L. against the Heterodera zeae were carried out to identify phytochemicals lethal to this economically important cyst nematode. In vitro investigation of a polar extract and fractions showing activity led to the isolation of phenolic compounds (flavonoids and phenolic acids). In the nonpolar extract, a few fatty acids, their methyl esters, and thiophenes (including α-terthienyl) were detected. In studies of compounds obtained commercially, α-terthienyl and gallic and linoleic acids showed 100% mortality at concentrations of 0.125% after 24 h. Assessment of structure-activity relationships revealed that an increase in the number of hydroxyl groups in phenolic acids increased the activity; with fatty acids, activity depended on chain length and the number and position of double bonds. Crude extracts of the flowers of different colors also have promising activity.
authors.affiliation: HEJ Research Institute of Chemistry, International Centre for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan. shaheenfaizi@hotmail.com
authors.forename: Shaheen
authors.initials: S
authors.lastname: Faizi
authors.forename: Shahina
authors.initials: S
authors.lastname: Fayyaz
authors.forename: Samina
authors.initials: S
authors.lastname: Bano
authors.forename: Erum Yawar
authors.initials: EY
authors.lastname: Iqbal
authors.lastname: Lubna
authors.forename: Humaira
authors.initials: H
authors.lastname: Siddiqi
authors.forename: Aneela
authors.initials: A
authors.lastname: Naz
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D005419:Flavonoids / Q000032:analysis; D035264:Flowers / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000032:analysis; D007814:Larva / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D031686:Tagetes / Q000737:chemistry*; D013876:Thiophenes / Q000032:analysis / Q000494:pharmacology; D014431:Tylenchoidea / Q000187:drug effects*
chemical_list: D000969:Antinematodal Agents; D005227:Fatty Acids; D005419:Flavonoids; D062385:Hydroxybenzoates; D010936:Plant Extracts; D013876:Thiophenes; C017616:phenolic acid