**Abstract**

Pests are responsible for most losses associated with agricultural crops. In addition, due to the indiscriminate use of synthetic pesticides, several problems have arisen over the years, such as pest resistance and contamination of important planetary sources such as water, air and soil. This awareness regarding pest problems and environment has led to the search for powerful and eco-friendly pesticides that degrade after some time, avoiding pest persistence resistance, which is also pest-specific, non-phytotoxic, nontoxic to mammals, and relatively less expensive in order to obtain a sustainable crop production Biodegradable biomimetic pesticides can be a potential green alternative to the pest industry.

**Keywords:** biopesticides, biomimetic, phytochemistry

#### **1. Introduction**

Chlordecone (CLD, **Figure 1**), a chlorinated insecticide, with a homocubane structure was used in Guadeloupe and Martinique (French West Indies (FWI)) to control the banana weevil, *Cosmopolites sordidus* from 1971 to 1993. Larvae of this insect are the most destructive stage, and they use their strong mandibles to escavate and create tunnels or galleries in the rhizome of banana trees [1]. To fight against this insect in the FWI, CLD was marketed in France from 1981 to 1993 as a formulation called Curlone®. The authorization for CLD was withdrawn by the French Ministry of Agriculture in 1990 but used in the FWI until September 1993. The estimated chlordecone amount applied over this time is 300 tons [2]. CLD is a very stable compound due to its high persistence; consequently, the entire environment (soil, surface, ground water and costal marine waters) and food chain remain contaminated. Therefore, animals, raised in banana production areas, are affected by this molecule [3, 4].

In banana cultivated areas of Guadeloupe, CLD concentrations between 0.1 and 37.4 mg.kg−1 can be found in topsoil and up to 10 μg.L−1 in aquatic systems [5]. Following the contamination of foodstuffs, the population of Guadeloupe and Martinique is exposed to chlordecone contamination through the consumption of

#### **Figure 1.**

*Chlordecone (left) and sordidin (right) structures.*

contaminated food and drinking water [6]. As a consequence, 92.5% of Martinicans and 94.9% of Guadeloupeans have detectable concentrations of CLD in their blood [7]. Several epidemiological studies were conducted to determine the health impact of this exposure. A correlation between pre- and postnatal chlordecone exposure and short-term memory and fine motor skills in young infants in the TIMOUN study [8–10]. CLD presents also endocrine disrupting properties [11] and is associated to type 2 diabetes [12]. Recent studies show that CLD exposure may be associated with altered epigenetic marks [13] and autoimmune diseases [14].

When CLD was prohibited in 1993, a weevil trap containing a pheromone, sordidin (**Figure 1**) was used [15]. Sordidin is a male-produced aggregation pheromone of banana weevil, related to ketal pheromones from Scolytids [15]. The production of this pheromone was first evidenced by Budenberg *et al.* in 1993. It was then identified and isolated in 1995 by Ducrot *et al*. as a major pheromone. Sordidin was first synthesized using the regioselective Baeyer-Villiger reaction of 2,6-disubstituted cyclohexanon as a key step, giving a mixture containing 4 stereoisomers. Trap system using this hormone is employed in the FWI and the Canary Islands. This trap supposes an interesting alternative mimicking the natural hormone allowing to substitute the use of CLD. A study of two plantations of over 200 hectares each shows a reduction in corm damage of 62.86% after the implantation of this biomimetic strategy [16].

The environmental problems produced by the CLD have led to the search for powerful and eco-friendly biomimetic pesticides as sordidin. These biomimetic pesticides should be: biodegradable (avoiding pest persistence); pest-specific; non-toxic to mammals and plants; and relatively less expensive in order to obtain a sustainable crop production.

Biomimetic compounds, as biopesticides, are obtained by synthetic routes which tend to transpose enzymatic reactions within the framework of synthetic organic chemistry. The concept of biomimetic synthesis of natural products was introduced by Robinson, following his straightforward synthesis of tropinone reported in 1917 [17, 18]. Several years later, the different ideas and the philosophy covering the biomimetic or biogenetic type synthesis was proposed by Van Tamelen in his work in 1961 [19]. Biomimetic synthesis can also describe a sequence of reactions carried out to

*DOI: http://dx.doi.org/10.5772/intechopen.105158 Biomimetic and Hemisynthetic Pesticides*

support a biogenetic hypothesis which is generally accepted with succeeded reactions [20]. Poupon, Nay and coworkers have compiled the biomimetic syntheses of several families of organic compounds including alkaloids [21], terpenoids, polyphenols and polyketides (as sordidin) [21]. Over past decades, numerous publications contain the biomimetic term associated with organic synthesis but also sensoring particularly in the pollution control field. For example, we may notice an increasingly use of molecular imprinted polymers as recognition elements in mimicking molecular/ionic recognition by natural receptors [22, 23]. Khadem *et al.* have designed an electrochemical selective sensor to determine the dicloran by modifying the working electrode with molecular imprinted polymer [24]. Liu *et al.* have developed a biomimetic absorbent containing the lipid triolein embedded in the cellulose acetate spheres to remove persistent organic pollutants from water [25]. More recently, Sicard *et al.* have proposed a strategy for the decontamination of organic pollutants combining pesticides and drugs based on the use of nucleolipids, polymer-free bioinspired materials. The advantage of using the latter lies in their degradation providing nontoxic natural biomolecules [21], such as nucleosides, phosphates, and lipids [26].

The present chapter shows a compilation of biomimetic and hemisynthetic pesticides, classified by several different mechanisms affecting one or more biological systems, including:


#### **2. Pesticides targeting nervous system**

Insects have a simple nervous system with a brain linked to a ventral nerve cord that consists of paired segmental ganglia running along the ventral midline of the thorax and abdomen (**Figure 2**). An insect's brain is a complex of six fused ganglia located dorsally within the head capsule. These ganglia can be separated in 3 pairs:


Below the brain another complex of fused ganglia, the subesophageal ganglion innervates mandibles, maxillae, labium, the hypopharynx, salivary glands, and neck muscles. In the thorax, three pairs of thoracic ganglia control locomotion by innervating the legs and wings. Thoracic muscles and sensory receptors are also associated with these ganglia. Similarly, abdominal ganglia control movements of abdominal muscles [28]. In some insects, the thoracic ganglia fuse to form a single ganglion.

**Figure 2.** *Nervous system of the grasshopper [27].*

Similarly, sometimes most of the abdominal ganglia are fused to form a single compound ganglion as in the blood sucking bug.

From molecular point of view, several receptors can be explored targeting the nervous system at different levels. These receptors are: i. Glutamate-gated chloride channels, ii. Voltage-gated sodium channels, iii. Transient receptor potential vanilloid channels, iv. Gamma-amino butyric acid receptors, v. Octopaminergic system and vi. Nicotinic acetylcholine receptors.
