Chalcones provides a skeletal framework for the synthesis of various bioactive heterocyclic compounds through condensation and ring closure reactions. There are many methods reported for the synthesis of chalcones but are usually prepared by the Claisen-Schmidt condensation reaction of a substituted acetophenone and a substituted aromatic aldehyde in presence of aqueous alkali ( Prasad et al., 2007, Rao et al., 2004). Chalcones, flavones and chromones have been studied as insect antifeedant activities ( Morimoto et al., 2003, Janaki et al., 2016, Susurluk et al., 2007).
Flavonoids are the well-known functional secondary metabolites, widely spread in the various plant species ( Panche et al., 2016). Such type of reactivity may be affected by the presence of substituents on aromatic rings or by α-X-substitution of the enone system ( Amslinger et al., 2013).Ĭhalcones belong to the class flavonoid and are used as the main precursor of flavonoids and isoflavonoids. The electrophilic nature of the α,β-unsaturated carbonyl system is the key factor which makes it capable to form irreversible bonds with other bioactive macromolecules, resulting different types of bioactivity. Chalcones provide a skeletal framework for a variety of novel biologically active heterocycles of high therapeutic potential and good medicinal profile ( Zhuang et al., 2017). The chemistry of chalcones is always going be a point of attraction for researchers due its large number of derivatives, derived from the good number of replaceable hydrogens present on the aromatic rings.Ĭhalcones constitute the central core of biologically active heterocyclic compounds. Chalcones are very reactive species due to the presence of a conjugated enone system ( Ameta et al., 2011). Chalcones are considered as one of the most significant type of natural products found in various plant species. To achieve the eco-friendly, egalitarian and ethical pest management, there is a need of a mechanism which provides pest specific, less toxic and cost-effective procedure.Ĭhalcones are commonly known as α, β-unsaturated ketone consisting of two aromatic rings which are joined by three carbon chain. The presently used pesticides for agricultural work to control insects and mealy bugs are highly toxic in nature for the human life. Selection of proper insecticide is one of the important requirements for the crop sustainability, which ensure the less toxicity to humans and more specific to key pests. The abilities of this insect pest to breed rapidly, migrate, and feed on a wide range of host plants, makes it very difficult to control ( Maruthadurai and Ramesh, 2020, Deshmukh et al., 2020). It is a destructive insect pest responsible for major problems in agricultural crop production, especially maize ( Maruthadurai and Ramesh, 2020). It causes infestation in crops leading to the severe crop losses ( Assefa and Ayalew, 2019).
Spodoptera frugiperda also known as the fall armyworm is a highly polyphagous migratory lepidopteran pest species. It infects a wide range of crops including wheat, soybean, millets, peanut, sorghum, sugarcane and corn. Bis-chalcones showed more toxicity than mono-chalcones and 6b causes the most toxic and dietary change. The larvae fed with aggregate in the bis-chalcones diet: 6b, 6e and 6f had the highest percentage of intake and the poorest conversion of nutrient absorption (ECI), which suggests that the larva metabolizes food for energy and results in a decrease of growth and death in early stages. Adults who survived showed malformations and decreased size, which led to death. frugiperda in the first larval stages, being 6b the most toxic (85%). The bis-chalcones 6b, 6e, 6f and 6h caused lethal effect on S. Toxicity was assessed through larval, pupal mortality and the emergence of adults and nutritional effects with consumption rates (IC), growth (GR) and consumption efficiency (EIC). The antifeedant activity was calculated when 50% of the larvae control ate 50% of the diet through the FR factor. To attain the crop sustainability, the antifeedant, toxicity and nutritional effects on larvae of Spodoptera frugiperda were studied with six mono- and eight bis- substituted chalcones. Being a new invasive parasite, its susceptibility to insecticides needs to be explored and therefore, there is an urgent need to develop the potent insecticides for the effective control of this insect pest. It causes infestation in crops leading to the severe crop losses. Spodoptera frugiperda is a highly polyphagous migratory lepidopteran pest species.