Mango ginger (Curcuma amada Roxb.) rhizome essential oils as source of environmental friendly biocides: Comparison of the chemical composition, antibacterial, insecticidal and larvicidal properties of essential oils extracted by different methods

The essential oil isolated from plants is widely utilized as eco-friendly biocides and antibacterial agents. Curcuma amada, commonly known as mango ginger, is well-known for its applications in the food and aromatics industry for its significant mango-like aroma. The present study compared the different C. amada essential oils prepared by hydrodistillation (CHD), steam distillation (CSD), microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), for their chemical composition, antibacterial, larvicidal and insecticidal properties. GC/MS analysis indicated the presence of compounds including α-pinene, β-myrcene, p-cymene, (Z)-β-ocimene, Camphor, linalyl acetate, safrole, ar-curcumene, and β-curcumene in the different C. amada essential oils. The antibacterial activity was observed against different strains of microbes, with a higher efficacy in the essential oils prepared by UAE and MAE methods. Apart from these, the MAE, UAE, CSD, and CHD were also shown to have significantly higher larvicidal activity against Aedes, Culex, and Armigeres species; however, no toxic effect was observed in non-targeted species like fishes and Allium cepa model of genotoxicity. Further, these essential oils were also found to have significant contact and fumigant toxicity as well as repellency against pests of stored grains (Sitophilus and Tribolium). Considering these results, the present study assumes that Curcuma amada essential oils may be a source of ecofriendly insecticides and antibacterial agents.