Rotenone pesticidal activity

Plants are known to produce compounds such as rotenone (1) which have been useful as pesticides. However rotenone and the plants from which it is derived were first known for their toxicity to fish. Thus fish toxicity is a useful measure of possible pesticidal activity and the potential of the plant to provide crop protection. 

The risks associated with pesticides that are in use in organic farming have hardly been investigated. Most pesticides allowed in organic farming are of natural origin such as silicates or extracts of medicinal plants. As far as active ingredients are concerned, only three are permitted Rotenone, pyrethroids and copper. 

In addition to their potential as antitumor agents, acetogenins have great potential as natural "organic" pesticides (Mikolajczak et al., 1988,1989 McLaughlin et al., 1997). Bullata-cin (1) and trilobacin (3) (see Figure 13.1) were more potent than rotenone, a classic complex I mitochondrial inhibitor, in a structure-activity relationship (SAR) study using yellow fever mosquito (YFM) larvae (He et al., 1997). 

Although this natural substance is present in a number of plants, the sonrce of most rotenone nsed in the United States is the dried derris root imported from Central and South America. It is formulated as dusts, powders, and sprays (less than 5% active ingredient) for use in gardens and on food crops. Many prodncts contain piperonyl butoxide as synergist, and other pesticides are inclnded in some commercial products. Rotenone degrades rapidly in the enviromnent. Emulsions of rotenone are applied to lakes and ponds to kill fish. 

In reality, pesticides of botanical origin have been used for centuries to protect crops and stored products and to repel pests from human habitations. Among the most well known are pyrethrum, neem, rotenone, nicotine and plant essential oils, although more than 2,000 plant species have been found to possess insecticidal activity [3-4]. However, while most botanical pesticides are known solely for their insecticidal activity, plant essential oils are also known for their uses as fragrances, flavorings, condiments or spices, and many are also considered to have medicinal uses. Given this widespread use, numerous plant essential oils are already widely available and their chemistry is generally well-understood. 

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