Parasiticidal activity

As the causative parasites for these diseases are closely related, and the genome of each has been sequenced, it is not surprising that a number of common biochemical pathways have been targeted by drug discovery efforts [6]. In addition, screening for parasiticidal activity of compounds has frequently been performed simultaneously against representative strains of the three major parasites, hence many of the chemotypes described in this chapter exhibit activity against all three. 

C-H bond unreactive to insertion, 1160 dioxirane oxidation, 1156 Sulfonic acids, C-H bond unreactive to insertion, 1160 Sulfonyl endoperoxides parasiticidal activity, 1309 synthesis, 1306-9, 1332 Sulfonyl peroxides, 1001-2, 1004-7 Sulfonylperoxy radical, superoxide reactions, 1035-9 Sulfoxidation... 

Other Parasiticides. The parasiticides described below have a relatively limited usage owing to a narrow spectmm of antiparasitic activity or because of the introduction of inherently safer or more effective products. 

A few commercial applications of benzofuroxans have been suggested in the Patent literature and elsewhere. A wide range of biological activity (fungicidal or fungistatic,bactericidal,i -parasiticidal,i3i and insecticidaP i i jj s been claimed for... 

O Neill and coworkers were also able to spin-trap the previously proposed C-centred radical 63b with sodium 3,5-dibromo-4-nitrosobenzenesulphonate (DBNBS) and the EPR of the adduct 64b was characteristic of a secondary radical (Scheme 19B). It was suggested that the parasiticidal action of arteflene stems from the alkylating properties of the radical intermediate or possibly from the enone 63a, which may be able to react with intracellular nucleophiles by a Michael addition. The enone itself did not exhibit antimalarial activity, possibly due to extracellular detoxification by glntathione before reaching its intraparasitic site of action. 

Like avermectins, the milbemycins have also undergone extensive molecular modifications. A number of synthetic milbemycins have been found to possess a wide-spectrum of parasiticidal and insecticidal activities [67-83]. The structure-achv-ity analysis would indicate that the milbemycins having different functional groups at positions 13,14 and 5 generally retain biological activity. The important milbemy-cin derivatives thus prepared include 13-substituted milbemycins of the type 31 [64,73-75] and 32 [76-78], 14-substituted milbemycins (33) [79], 5-keto/oximinomilbe-mycins (34) [81,82], 35 [80] and 36 [83]. 

The nematocidal activity of 38 quassinoids, C19 or C20 was measured by using a species of Diplogastridae (Nematoda) to develop lead parasiticides [114], From various quassinoids tested, samaderine B (11) displayed the most potent nematocidal activity with a minimum lethal concentration (MCL) of 2.0 x 10 5 M. 

The nematocidal activities of samaderine B (11) was 15-fold greater than that of albendazole (3.0 x 10"4 M), 10-fold greater than that of thiabendazole (2.0 x 10-4 M) and 7.5-fold greater than that of avermectin (1.5 x 10 4 M). Thus, samaderine B (11) may eventually be used as lead parasiticides. 

The term germicides refers to a group of chemicals used at a world level in agricultural products with the aim to control, destruct, or inhibit weeds, insects, fungi, and other harmful plants or animals. Approximately 320 active ingredients of parasiticides are available in thousands of different combinations. ... 

Most chemotherapeutic agents registered and labeled for use as external parasiticides for large animals are pyrethroids. Pyrethroids used in veterinary medicines for domestic animals are listed in Table 137.1. For some spot-on products, particularly those intended for use on large animals and containing active ingredients... 

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