A Quantitative Structure-Activity Relationship Study of Insecticidal Activity of Propargyloxy-Naphthalene-Sulfonamide Derivatives

A series of compounds bearing insecticidal properties were quantitatively examined using chemometric 3D-descriptors.The series, consisting of propargyloxynaphthalene-sulfonamide derivatives, has exhibited actions against third-instar larvae of Mythimna separate.The lethal concentration required to reveal 50% effect (LC 50 mg ml -1 ) on the larvae of M. separate has been expressed on a negative logarithm scale on a molar basis as pLC 50 (M) and was correlated with molecular 3D-descriptors.The QSAR models developed statistically gave rationale to explain the insecticidal effects of the compounds of the series.The possible mechanism of action at the molecular level may further be anticipated through the highest significant model.The DRAGON software was employed to obtain the descriptors for the energy-minimized 3D-structures for each compound of the series.All descriptors were scaled between 0 and 1 and subjected to filtering processes embedded in the combinatorial protocol in multiple linear regression, CP-MLR computational software to develop unique significant models between pLC 50 (M) and the most influential 3D-descriptors.The radial distribution function-6.0/weightedby the atomic Sanderson electronegativities (RDF060e) and the 3D-Morse signal 28/weighted by atomic masses (Mor28m) were the essential descriptors filtered for the compounds in the series.The direction of their influence on the activity profile has been revealed by the sign of the regression coefficient linked to these descriptors.The electronegativity and the molecular mass (bulk) weighted descriptors play crucial roles in explaining the insecticidal actions of the compounds.