title: Chirality index, molecular overlay and biological activity of diastereoisomeric mosquito repellents.
abstract: Both 1-methylisopropyl 2-(2-hydroxyethyl)piperidine-1-carboxylate, (Picaridin((R))) and cyclohex-3-enyl 2-methylpiperidin-1-yl ketone (AI3-37220; 220) have two asymmetric centers, and the four diastereoisomers of each compound are known to have differing degrees of mosquito-repellent activity according to quantitative behavioral assays conducted at the United States Department of Agriculture. Computational chemistry was used to identify the structural and configurational basis for repellent activity. Molecular overlay of the optimized geometries of the lowest energy conformers of the diastereoisomers was investigated to elucidate the role of chiral centers in 220 and Picaridin. It was found that the presence of a chiral carbon alpha to the nitrogen with the S configuration in the piperidine ring is essential to the three-dimensional arrangement of the atoms of the pharmacophore for effective repellent activity.
authors.affiliation: Natural Resources Research Institute, University of Minnesota Duluth, Duluth, MN 55811, USA. pekar@sci.muni.cz
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Natarajan
authors.forename: Subhash C
authors.initials: SC
authors.lastname: Basak
authors.forename: Alexandru T
authors.initials: AT
authors.lastname: Balaban
authors.forename: Jerome A
authors.initials: JA
authors.lastname: Klun
authors.forename: Walter F
authors.initials: WF
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D001681:Biological Assay; D009033:Culicidae; D003671:DEET / Q000737:chemistry; D007302:Insect Repellents / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D007302:Insect Repellents; D010880:Piperidines; D003671:DEET; C075892:1-(3-cyclohexen-1-ylcarbonyl)-2-methylpiperidine; C483506:picaridin