GC-MS Chemical Profiling, Total Phenolic Mapping, and Larvicidal Efficacy of Ocimum suave Leaf Essential Oils

International Journal of Chemistry | Vol. 13, No. 4, April 2022 | pp. 25–32

DOI: 10.46882/2022/IJC/000162

Article Type: Original Research Paper

Title: GC-MS Chemical Profiling, Total Phenolic Mapping, and Larvicidal Efficacy of Ocimum suave Leaf 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 rampant spread of vector-borne illnesses in tropical eco-zones demands the identification of alternative botanical formulations to minimize chemical insecticide hazards in agricultural and aquatic systems. This research reports the qualitative chemical characterization, volatile compound identification via Gas Chromatography-Mass Spectrometry (GC-MS), and in vitro larvicidal efficacy of Ocimum suave leaf essential oil against Culex quinquefasciatus fourth-instar larvae. Essential oils obtained via hydro-distillation in a Clevenger apparatus were separated into 22 distinct peaks through GC-MS profiling, with methyl eugenol (45.8%), beta-caryophyllene (14.2%), and eugenol (11.5%) emerging as the primary bioactive constituents. Larvicidal bioassays were conducted utilizing contact toxicity tests across a suite of oil concentrations (20 to 100 mg/L) over 24-hour exposure periods. The essential oil demonstrated significant lethal potency, yielding an LC50 value of 42.6 mg/L and an LC90 value of 78.4 mg/L against the mosquito larvae populations. A linear correlation was observed between the concentration of oxygenated phenylpropanoids and larval mortality rates. This confirms that volatile aromatic components actively disrupt the respiratory and acetylcholinesterase enzymes of the larvae, providing a sustainable botanical framework for vector population management.

Keywords: Ocimum suave; Essential oils; GC-MS analysis; Methyl eugenol; Larvicidal bioassay; Culex quinquefasciatus

Manuscript Timeline: Received: June 15, 2021; Revised: July 28, 2021; Accepted: August 22, 2021; Published: April 02, 2022.

Citation: Abdulrahman, S. A., & Santos, G. E. D. M. (2022). GC-MS Chemical Profiling, Total Phenolic Mapping, and Larvicidal Efficacy of Ocimum suave Leaf Essential Oils. International Journal of Chemistry, 13(4), 25–32.

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