Anticoagulant rodenticides first-generation

As reviewed by Ujvary some of the earliest natural product-based pesticides were those for the elimination of vertebrate pests. For example, strychnine (Fig. 19), obtained from seeds of Strychnos nux-vomica, is a rodenticide that is an antagonist to the neurotransmitter glycine and is used against a few mammal species, as well as pest birds and fish. The first generation of anticoagulant rodenticides were based on dicoumarin. 

An even more important derivative is 3-[3-(4 -bromobiphenyl-4-yl)-1,2,3,4-tetrahydronaphth-l-yl]-4-hydroxycoumarin (brodifacoum, 35). This anticoagulant of exceptional potency is capable of control resistant rodents as well as several noncommensal species. Contrary to first generation anticoagulants, a bait concentration of only SO mg/kg brodifacoum is adequate to give control even in a single feeding for most species. As with other anticoagulants, vitamin K, is an effective antidote. In contrast with other acute rodenticides, symptoms are delayed and no bait shyness is observed (Dubock and Kaukeinen, 1978). Its effectiveness... 

Brodifacoum [3-(3-(4 -bromobiphenyl-4-yl)-l,2,3,4-tetrahydro naphth-l-yl)-4-hydroxycoumarin] is one of the newer and more potent second-generation anticoagulant rodenticides. It was first introduced in 1977 by Sorex Ltd. of London, and then developed by the Imperial Chemicals Incorporated (ICI) Plant Protection Division (Chalermchaikit et al., 1993). 

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