Inverse Correlation between Lethality and Thermodynamic Stability of Contact Insecticide Polymorphs

• DOI: 10.1021/acs.cgd.8b01800
• Publication Date: 2019-02-05T10:57:45Z
• Authors: Jingxiang Yang; Xiaolong Zhu; Chunhua T. Hu; Mengdi Qiu; Qiang Zhu; Michael D. Ward; Bart Kahr
• Keywords: Chemical Stability; Lindane; Toxicant; Crystal (programming language)

Contact insecticides often involve the interaction of whole organisms and toxicant crystal surfaces. The crystalline phase these compounds has not, however, been considered for optimization insecticide performance. Lindane (1R,2r,3S,4R,5r,6S-hexachlorocyclohexane) one most widely used insecticides, but other (inactive) stereoisomers accompanying its manufacture have led to massive chemical waste remediation problems. Crystalline polymorphs are also isomers in broadest sense, yet only structure lindane reported. Herein, we report discovery characterization two new polymorphs, Forms II III. efficacy I, II, III against Drosophila melanogaster revealed an inverse correlation between lethality thermodynamic stability; least stable kills fastest. This understanding provides a engineering opportunity wherein formulations containing active contact polymorph can achieve infectious disease prophylaxis while reducing environmental exposure associated waste.