Antiparasitic activity

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. 

Thiazole, 5-amino-4-ethoxycarbonyl-2-methyl-synthesis, 6, 306 Thiazole, 2-amino-4-(2 -furyl)-bromination, 6, 256 Thiazole, 2-amino-4-hydroxy-synthesis, 6, 296 Thiazole, 5-amino-2-hydroxy-synthesis, 6, 301 Thiazole, 5-amino-2-mercapto-synthesis, 6, 301 Thiazole, 2-amino-4-methyl-alkylation, 6, 256 synthesis, 6, 300 Thiazole, 2-amino-5-nitro-antiparasitic activity, 1, 180... 

In summary, a novel cyclohexyl avermectin analog B1 with enhanced antiparasitic activity was discovered and produced with high selectivity and excellent fermentation titer through deciphering biosynthesis, pathway engineering, and directed evolution. The new product, doramectin, is sold commercially as Dectomax. 

Page, A.P., Kumar, S. and Carlow, C.K.S. (1995a) Parasite cyclophilins and antiparasite activity of cyclosporin A. Parasitology Today 11, 385-388. 

In this review, we use the terms, biologically active or bioactive for any substance which elicits some biological response in another organism. Early investigations on bioactive marine isonitriles focussed on compounds that might serve as chemical defense agents (cf. Sect. 5.1). As chemists began to resolve mixtures into individual components, other tests related to antiviral, antimicrobial, or antiparasitic activity, were reported. Often, bioassays were performed... 

There is a great deal of evidence that AmB can exert a number of effects directly on cells of the immune system, and particularly on macrophages to increase nonspecific defense mechanisms against pathogens and cancer cells. These mechanisms include the production of nitric oxide (NO) (32) and tumor necrosis factor alpha (TNF-a) (33), which could contribute to the antifungal and antiparasitic activity of AmB. However, excess TNF-a production could also be responsible for some of the side effects associated with AmB treatment, such as fever and chills. 

The drugs most frequently used in the treatment of Chagas disease are nifurtimox and benzni-dazole. But both of them have very low antiparasitic activity in the chronic stage of the disease and... 

Copp, B. R., Kayser, O., Brun, R. and Kiderlen, A. F. 2003. Antiparasitic activity of marine pyridoacridone alkaloids related to the ascididemins. Planta Medica, 69 527-531. 

Antiparasitic activity. Oleo-gum resin from roots and stems was active on Trichomonas vaginalis ... 

Avermectin and its derivatives are utilized for their antiparasitic activities in veterinary medicine. They also have anticonvulsant effects. Difluorinated analogues in positions... 

Sharma U, Singh D, Kumar P, Dobhal MP, Singh S. Antiparasitic Activity of Plumeri-cin Isoplumericin Isolated from Plumeria bicolor against Leishmania donovani. Indian Journal of Medical Research 2011 134(5) 709-716. 

A pharmacological effect may be observed only when food contains elevated concentrations of potent therapeutics, as in the case of the -blocker carazo-lol whose residues in tissues caused sedation residues of the -agonist clenbuterol that produced bronchodilatory action and residues of the anthelminthic ivermectin that produced antiparasitic activity (51). 

Derivatives of 2-amino-5-nitrothiazole have antiparasitic activity. Niridazole (253) is used in the treatment of schistosomiasis, but its side-effects make it unattractive for treating other diseases, e.g. amoebiasis, for which safer drugs are available. The nitroimidazole metronidazole (254) is particularly useful in amoebiasis and trichomoniasis, and the latter disease may also be treated with nimorazole, l-morpholinoethyl-5-nitroimidazole. 

Suramin (refer to Box 3.1, where the structure of this compound is shown), which was used against trypanosomes, was developed by Paul Ehrlich. It was one of the first drugs to be developed by the discovery method to cure a specific ailment. Suramin is a derivative (a variation) of a fabric dye that was found to have antiparasitical activity, (a) Would you expect suramin to undergo delocalization of electrons ... 

The most important activity of cyclosporin A consists clearly in the marked suppression of antibody formation and cell-mediated immune response [4, 5]. In addition, the metabolite exhibits antiphlogistic effects, restricted to chronic inflammation processes, as well as antifungal and antiparasitic activities. Whether these different biological activities are inter-related or represent separate mechanisms is still an open question. Considering immunosuppression, early observations revealed that cyclosporin A acts selectively on lymphocytes, mainly on T cells, affecting rather the inductive phase than the proliferative phase of lymphoid cell populations. Apparently, cyclosporin A inhibits primary T-helper cell activation and blocks the formation of... 

Ivermectin possesses a broad spectrum of antiparasitic activities [51] and is a 22,23-dihydro analogue of the macrocyclic lactone, avermectin B,. Ivermectin is highly effective against microfilariae of O. volvulus at very low doses (50-200/ig/kg) [52] and in comparison with DEC, induces only mild mazzotti reactions and other side-effects. Its effectiveness against D. viteae in M. natalenis [38] and D. immitis [53] is also documented. 

Carbohydrate metabolism provides the main energy source in coccidia. Diets deficient in thiamin, riboflavin, or nicotinic acid—all cofactors in carbohydrate metabolism—result in suppression of parasitic infestation of chickens by E tenella and E acervulina. A thiamin analog, amprolium—1-[(4-amino-2-propyl-5-pyrimidinyl)-methyl]-2-picolinium chloride—has long been used as an effective anticoccidial agent in chickens and cattle with relatively low host toxicity. The antiparasitic activity of amprolium is reversible by thiamin and is recognized to involve inhibition of thiamin transport in the parasite. Unfortunately, amprolium has a rather narrow spectrum of antiparasitic activity it has poor activity against toxoplasmosis, a closely related parasitic infection. 

Boulanger, N Munks, R.J., Hamilton, J.V., et al. (2002) Epithelial innate immunity. A novel antimicrobial peptide with antiparasitic activity in the blood-sucking insect Stomoxys calcitrans. J. Biol. Chem. 277(51), 49921 19926. 

It can be mentioned the work of Cerecetto et al. [ 133,134] where the anti-7 cruzi activities of a series of QDO and its vanadyl complexes were correlated with theoretical physicochemical descriptors. On the one hand, a clear two-variable correlation was found between both QDO-antiparasite activity and theoretical lipophilicity and LUMO energy [133]. The equation confirms some previously observed aspects, i.e., that the presence of an electron-withdrawing substituent, like halogen, in 5-8-positions produces more active compounds. On the other hand, it was found that the anti-T. cruzi response of a family of QDO-vanadyl complexes depends on the lipophilic properties and the electronic properties, am, of 6-7-substituents [134], Another QSAR study involving PDO derivatives with selective hypoxic cytotoxicity was performed by these researchers [145]. In this case, electrochemical properties, expressed as pc, together with lipophilicity correlated to the fraction of cell survival in hypoxia finding that when the redox potential of the N-oxidc moiety decreases the hypoxic cytotoxicity increase. 

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