Chemical Composition and Evaluation of Antifungal and Insecticidal Activities of Essential Oils Extracted from Jambosa caryophyllus (Thunb.) Nied: Clove Buds.

Jambosa caryophyllus has been used in traditional phytotherapy as a treatment against infections. In the present work, essential oils extracted from clove buds ( Jambosa caryophyllus ) (EO-JC) were investigated for their composition, antifungal, and insecticidal properties. Extraction of EO-JC was performed by use of hydrodistillation using a Clevenger-type apparatus, and the EOs were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Antifungal activity of EO-JC was evaluated by the use of solid-state diffusion (disc method) and microdilution to determine the minimum inhibitory concentration (MIC), against three strains of fungus, Aspergillus niger , Aspergillus flavus, and Fusarium oxysporum . Insecticidal activity of EO-JC against the cowpea weevil, Callosobruchus maculatus , was determined to assess utility of EO-JC to control this pest. Several exposures including inhalation and contact were used to determine lethality, as well as the repulsion test was conducted at concentrations of 4, 8, 16, and 32  μ L EO-JC. Characterization of EO-JC by GC/MS revealed 34 compounds accounting for 99.98% of the mass of the extract. The predominant compound was eugenol (26.80%) followed by β -caryophyllene (16.03%) and eugenyl acetate (5.83%). The antifungal activity of EO-JC on solid media exhibited inhibitions in the range of 49% to 87%, and MIC was between 3.125 and 7.80  μ g EO-JC/mL. Insecticidal activity, as determined by the use of the inhalation test, and expressed as the LD 50 and LD 95 after 96 hours of exposure was 2.32 and 21.92  μ L/L air, respectively. In the contact test, a 96-hour exposure resulted in LD 50 and LD 95 of 5.51 and 11.05  μ L/L of air, respectively. EO-JC exhibited insecticidal activity against fungi and pest chickpea weevil.