Synthesis, Herbicidal Activity and Toxicity Evaluation of Secondary Ammonium Salts from Turpentine Oil for Sustainable Weed Control

Abstract

Three series of secondary ammonium chloride from turpentine were synthesized and evaluated as botanical herbicides. The preemergence herbicidal activities against ryegrass (Loliun multiflorum) and barnyard grass (Echinochloa crus‐galli) were investigated using water as the only solvent. Their toxicity was evaluated by cytotoxicity assays. Preliminary results demonstrated that the herbicidal performance of the prepared salts was similar or much higher than that of corresponding secondary amines and even commercial herbicide glyphosate. Promisingly, compound 14e containing a cyclohexyl‐substituted p‐menthene skeleton with an IC50 value of 0.0014 mM against root growth of ryegrass showed 39‐fold higher herbicidal activity than glyphosate. Besides, this compound was found to be nontoxic to human and animal cells, indicating the potential application as a water‐soluble herbicide for ryegrass control.

Longifolene-Derived Primary Amine Carboxylates for Sustainable Weed Management: Synthesis and Herbicidal Activity

“…The inhibition percentage of seed germination was the mean value obtained through three independent experiments, and the standard deviation values were limited within ±5%. On the basis of the series inhibition rate, values of half maximal inhibitory concentration (IC 50 ) were calculated from probit analysis using SPSS software . The root or shoot length of each seed was measured, and the inhibition rate (%) of the root or shoot growth was calculated according to the equation listed below y = x 0 − x 1 x 0 where y is the inhibition rate of the root or shoot growth, x 0 is the average root or shoot length of the blank control group in each test, and x 1 is the average root or shoot length of the group treated by the test compounds.…”

“…On the basis of the series inhibition rate, values of half maximal inhibitory concentration (IC 50 ) were calculated from probit analysis using SPSS software. 37 The root or shoot length of each seed was measured, and the inhibition rate (%) of the root or shoot growth was calculated according to the equation listed below…”