Biological mechanism of action

The biological mechanism of action is helieved to involve the production of superoxides near the DNA strand, resulting in DNA backbone cleavage and cell apoptosis. The actual mechanism is not yet known, but is believed to proceed from the reduction of molecular oxygen into superoxide via an unusual auto-redox reaction on a hydroxyquinone moiety of the compound following. There is also some speculation the compound becomes activated into its reactive oxazolidine form. 

Alagbala AA, McRiner AJ, Borsmik K, Labonte T, Chang W, D Angelo JG Posner GH, Foster BA. (2006) Biological mechanisms of action of novel C-10 non-acetal trioxane dimers in prostate cancer cell lines. J Med Chem 49 7836-7842. 

Tris(l,2-bis(dimethylphosphino)ethane)rhenium(I), [Re(DMPE)3]+ is a simple, symmetrical cation which contains three identical bidentate phosphine ligands. This complex provides a Re(II/I) redox couple with properties that are very convenient for the study of outer-sphere electron transfer reactions.1 Specifically, this couple is stable in both alkaline and acidic media and it exhibits a reversible, one-equivalent redox potential in an accessible region [ °,(II/I) = 565 mV vs. NHE]. Moreover, this complex has been used to obtain information about the biological mechanism of action of 186Re and l88Re radiopharmaceuticals.2,3... 

In some instances the microbes have made some innovations. The various members of the ferrichrome group have to be regarded as very sophisticated ligands and their existence underlines once more the fabulous synthetic capability of microorganisms. Fortunately, in the case of ferrichrome A a crystallographic structure has been worked out. This is certain to aid in the interpretation of the biological mechanism of action of these growth factors. At the same time the very detailed crystal... 

The use of modelling is based on a number of assumptions. The most important relate to the similarity of the modelled set of phenomena or events or cases (here chemical compounds). Any mathematical/statistical, chemical/biological modelling approach must either be based on fundamental ab initio theory without many adjustable parameters, or be derived as a Taylor or other serial expansions of such fundamental models. In the latter case the model is valid only locally , i.e. for moderate changes in its variables. In the present context, this corresponds to having only a moderate variation in chemical structure between the compounds included in one model, as well as only a moderate variation of the biological mechanism of action of the chemical compounds. If there is a wide variation, this necessitates the use of several models, one for each structural and biological-mechanistic type of compounds. 

The quantitative description of actual empirical data of the concentration-duration relationship can be expressed by any of a number of linear regression equations. In the assessment of empirical data reported by ten Berge et al. (1986), these workers quantified the exposure concentration-duration relationship by varying the concentration to the n power. Since raising c or t or both to a power can be used to define quantitatively the same relationship or slope of the curve and to be consistent with data and information presented in the peer-reviewed scientific literature, the equation C x t = k is used for extrapolation. It must be emphasized that the relationship between C and t is an empirical fit of the log transformed data to a line. No conclusions about specific biologic mechanisms of action can be drawn from this relationship. 

National Center for Toxicological Research (NCTR), FDA. 3900 NCTR Road, Jefferson, AR 72079, U.S.A. URL http //www.fda. gov/nctr/index.html. Mission Statement includes fundamental and applied research specifically designed to define biological mechanisms of action underlying the toxicity of products regulated by the FDA. Covers food safety, bioterrorism, biotechnology, information technology, fundamental and applied research, premarket activities, antimicrobial resistance, and HIV/AIDS. 

In an attempt to probe the biological mechanism of action of natural flavonols and to identify the relevant receptors for flavonols two analogues of kaempferol were synthesised by Tanaka et al., [119]. The target flavonols (242) were prepared by intramolecular dehydrative condensation of 241 with potassium carbonate in pyridine as shown in Fig. 

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