GC-MS Chemical Profiling, Quantitative Phytochemical Mapping, and Insecticidal Efficacy of Rosmarinus officinalis Essential Oils

International Journal of Chemistry | Vol. 15, No. 12, December 2024 | pp. 89–96

DOI: 10.46882/2024/IJC/000194

Article Type: Original Research Paper

Title: GC-MS Chemical Profiling, Quantitative Phytochemical Mapping, and Insecticidal Efficacy of Rosmarinus officinalis Essential Oils

Names of Authors: S. A. Abdulrahman¹, G. E. D. M. Santos²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Technology, Minna, Nigeria.
²Department of Chemistry, University of Campinas, Campinas, Brazil.

Abstract: The continuous emergence of chemical resistance among stored-grain insect pests requires the formulation of alternative botanical insecticides to minimize chemical pesticide hazards in agricultural facilities. This research reports the qualitative chemical characterization, volatile compound identification via Gas Chromatography-Mass Spectrometry (GC-MS), and in vitro insecticidal efficacy of Rosmarinus officinalis leaf essential oil against Acanthoscelides obtectus (Bean weevil). Essential oils obtained via hydro-distillation in a Clevenger apparatus were separated into 20 distinct peaks through GC-MS profiling, with 1,8-cineole (42.5%), alpha-pinene (18.2%), and camphor (12.4%) emerging as the primary bioactive constituents. Insecticidal bioassays were conducted utilizing contact toxicity tests across a suite of oil concentrations (10 to 50 microliters/square meter) over 24-hour exposure periods. The essential oil demonstrated significant lethal potency, yielding an LC50 value of 18.4 microliters/square meter and an LC90 value of 34.2 microliters/square meter against the weevil populations. A linear correlation was observed between the concentration of oxygenated monoterpenes and insect mortality rates. This confirms that volatile monoterpenoids actively disrupt the respiratory and acetylcholinesterase enzymes of weevils, providing a sustainable botanical framework for grain storage protection.

Keywords: Rosmarinus officinalis; Essential oils; GC-MS analysis; 1,8-Cineole; Contact toxicity; Acanthoscelides obtectus

Manuscript Timeline: Received: June 15, 2023; Revised: July 28, 2023; Accepted: August 22, 2023; Published: December 04, 2024.

Citation: Abdulrahman, S. A., & Santos, G. E. D. M. (2024). GC-MS Chemical Profiling, Quantitative Phytochemical Mapping, and Insecticidal Efficacy of Rosmarinus officinalis Essential Oils. International Journal of Chemistry, 15(12), 89–96.

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