Toxicity, selective

Selective toxicity (selectivity) Difference in toxicity of a chemical toward different species, strains, sexes, age groups, etc. 

Molecular weight Predicted druglikeness Predicted solubility Predicted toxicity Selectivity... 

All of these compounds are inhibitors of dihydrofolate reductase in bacteria, plasmodia, and humans. Fortunately, they have a significantly higher affinity to bacterial and protozoal dihydrofolate reductase. Pyrimethamine, for example, inhibits dihydrofolate reductase in parasites in concentrations that are a several hundred times lower than that required to inhibit dihydrofolate reductase in humans. This is the basis of their selective toxicity. Selective toxicity can be elevated upon the host organism s production of folic acid, which parasites are not able to use. 

Key words PGVL Hub, combinatorial chemistry, library design, reaction, synthesis protocol, reactant, product, enumeration, filtering, Chkl, kinase, inhibitor, SAR, ADME T (Adsorption, Distribution, Metabolism, Excretion, and Toxicity), selectivity, solubility, protein-ligand complex. 

Recent research has focused on the identification of agents with greater selectivity, in vivo stability, and lack of toxicity. Selective antiretroviral agents that inhibit a critical HIV-1 enzyme such as... 

Selected chemical employed to measure the sensitivity of the test organisms in order to establish confidence in toxicity data obtained for a given test sample (or a batch of test samples). In most instances, a toxicity test with a reference toxicant is performed i) to confirm that test organisms (or cells) are in good physiological health for bioanalytical purposes at the time the test sample is evaluated, and ii) to assess the precision and reliability of results obtained by the laboratory for that reference toxicant. The toxicant selected should meet different properties as defined by Environment Canada, 1990. Volume 1(2,3,6,7,14), Volume 2(11). 

The need for scientific versus arbitrary limits An approach based on therapeutic dose An approach based on toxicity Selection of the best approach Microbial limits... 

The species, dose and time needed to induce injury and the appropriate endpoints will vary with the toxicant selected. The following is an example of such a model Procedure ... 

Currently, only copper-based products are approved by the United States Environmental Protection Agency for widespread use as an algicide in food-fish production ponds and municipal drinking water reservoirs in the United States. These copper-based products, such as copper sulfate and chelated copper compounds, are commonly used in aquaculture and in municipal drinking water systems. Unfortunately, copper-based algicides do not provide a large degree of toxic selectivity towards noxious... 

The unacceptable risks that synthetic herbicides pose to the environment and human health prevent their approval for use in drinking water supply systems and aquaculture ponds. The discovery of environmentally safe compounds that have a greater degree of toxic selectivity towards noxious species of cyanobacteria than copper algicides currently available would greatly benefit commercial aquaculturists and municipal drinking water suppliers and consumers. The use of natural products to selectively control cyanobacteria is desirable due to environmental safety issues and consumers negative perceptions of the use of synthetic compounds (herbicides). 

Among this class of compounds the development of 3-carboranyl thymidine analogs (3CTAs) has received special attention in recent years. In particular, the 3-(dihydroxypropyl-carboranyl-pentyl)thymidine derivative designated N5-20H (36) was shown to be very promising, due to its low toxicity, selective tumor cell uptake and high rate of phosphorylation into the corresponding... 

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