Identification and characterization of impurities in an insecticide, commercial chlorantraniliprole using liquid chromatography-tandem mass spectrometry.

RATIONALE: Ensuring the global safety and effectiveness of agrochemicals has become imperative. An in-depth understanding of impurity profiles of products is crucial, especially for high-demand agrochemicals, where impurities may be more toxic and persistent than original agrochemicals. This study focuses on the detection and identification of impurities in a commercial chlorantraniliprole (CAP), an anthranilic diamide class broad-spectrum insecticide. METHODS: Commercial CAP was collected from an agrochemical supplier in India and was analyzed using a high-performance liquid chromatography-photodiode array (HPLC-PDA) (Agilent 1260; wavelength, 220 nm) with a Zorbax RP SB-C18 (250 × 4.6 mm, 5 µm) column and liquid chromatography-mass spectrometry (LC-MS) (Agilent 6545 quadrupole time of flight (Q-TOF)) techniques to identify the impurities. The impurities were isolated by preparative HPLC using a Zorbax-DB C18 (250 × 9.4 mm, 5 µm) column. liquid chromatography- tandem mass spectrometry (LC-MS/MS) experiments (Q-TOF) were performed on CAP and its impurities to obtain their structural data. RESULTS: HPLC-PDA analysis of CAP showed four major impurities (IM-1 to IM-4) ranging from 0.76% to 4.1%. The positive ion electrospray ionization (ESI) mass spectra of CAP and its impurities showed dominant [M + H]+ ions in addition to [M + Na]+ , [M + K]+ , and [2M + Na]+ ions. High-resolution mass spectrometry (HRMS) data provided the elemental composition of the compounds, and isotopic distribution patterns revealed the number of Cl and/or Br atoms present in them. The structures of impurities were proposed based on the LC-MS/MS) data and further confirmed by nuclear magnetic resonance (NMR) data on isolated impurities/synthesis. CONCLUSION: The quality and impurities of CAP, a popular insecticide, must be assessed and described for its efficacy and safety. In this study, four impurities of CAP were detected using HPLC and successfully characterized using LC-HRMS, LC-MS/MS, and NMR data. The method is useful for verifying the purity of CAP as well as helping in the identification of its possible impurities.

N-Substituted piperazine-coupled imidazo[2,1-b]thiazoles as inhibitors of Mycobacterium tuberculosis: Synthesis, evaluation, and docking studies.

An innovative series of N-substituted piperazine-linked imidazothiazole derivatives 7(a-x) were synthesized, and their antitubercular effectiveness was evaluated. A three-step reaction sequence involving the condensation of 1,3-dichloroacetone and thiourea, coupling with substituted piperazines to give the intermediates 5(a-d) and cyclization with substituted α-bromoacetophenones produced the desired imidazothiazole derivatives 7(a-x) in excellent yields. In vitro screening of new derivatives against Mycobacterium tuberculosis H37Rv resulted in 7k (minimum inhibitory concentration [MIC]: 0.78 µg/mL) and 7g and 7h (MIC: 1.56 µg/mL) as potent hit compounds. Further, the docking studies of the promising compounds 7k, 7g, and 7h revealed that the best molecular interactions are with the DprE1 in complex with sulfonyl PBTZ of M. tuberculosis as the target protein (PDB ID: 6G83).