Monoterpenoids and Their Synthesized Brominate Derivatives as Eco-Friendly Measures to Control Some Plant Pathogenic Fungi and Bacteria

Background and Objective: Phyto-pathogenic fungi or bacteria are one of the most important causes that decrease food and cash crops. Chemical pesticides cause damage to the environment. Thus, globally, there are attempts to provide eco-friendly products. Therefore, this work aimed to find alternative natural products for managing serious diseases (fungi and bacteria). Materials and Methods: Fungicidal and bactericidal of four monoterpenoids, as well as their synthesized brominated (Br) derivatives were investigated against six fungi and four bacteria in vitro. The synthesized brominated derivatives were confirmed by a mass spectrometer and GC/MS. Results: The soil and air-borne fungi were very sensitive to chlorothymol followed by thymol and carvacrol, respectively. However, the synthesized brominate derivatives such as bromocarvacrol were the most effective treatment against all the tested fungal strains, while, bromoegunol was a less effective treatment. Concerning the antibacterial activity, the tested monoterpenoids exhibited variable degrees of antibacterial against all of the tested bacterial strains and the conversion of monoterpenoids into bromo-derivatives enhanced the bactericidal activity. Conclusion: The chlorothymol (monoterpene) recorded the highest fungicidal activity against soil and air-born fungi. For bacterial activity, results exhibited that chlorothymol was the most effective monoterpene against bacteria. All the bromo-derivatives showed high activity against the most of tested fungi and bacteria.