Specific biological activity

Specific biological activity of carboxylic acids peroxide derivatives in compaiison with their oxidation ability and ionization degree in aqueous solutions has been considered. Peroxyoctanoic, diperoxynonandioic and diperoxydecandioic acids give the most intense bactericidal effect among researched cai boxylic acids peroxide derivatives. The perspectives of use of the aliphatic middle-chain peracid C8-C9 as anti-infective agents have been discussed. 

Initial classification of some cytokines was also undertaken on the basis of the specific biological activity by which the cytokine was first discovered (e.g. TNF exhibited cytotoxic effects on some cancer cell lines CSFs promoted the growth in vitro of various leukocytes in clumps or colonies). This, too, proved an unsatisfactory classification mechanism, as it was subsequently shown that most cytokines display a range of biological activities (e.g. the major biological function of TNF is believed to be as a regulator of both the immune and inflammatory response). More recently, primary sequence analysis of cytokines coupled to determination of secondary and tertiary structure reveal that most cytokines can be grouped into one of six families (Table 8.2). 

It is clear that protein-carbohydrate interactions are essential in numerous biological processes and that the development of carbohydrate mimetics that interfere with these processes would provide a powerful methodology for both modulation and amelioration of specific biological activity. Since the early 1990s, novel... 

Dmgs in which fluorine atoms bring a specific biological activity to molecules that previously had no therapeutic activity. Most of the examples are enzyme inhibitors (difluoroornithine, gemcitabine, 5-fluorouracil). Synthesis of these drugs often comes from a rational approach that is based on the action mechanism. 

The Chemical Co-evolution Model was based on the assumption that every NP possessed (or had possessed at some stage in evolution) some biological activity that enhanced the fitness of the producer. This assumption is not supported by experimental evidence and the assumption has no theoretical basis. Extensive studies of collections of both synthetic chemicals and NPs have shown that the probability of any one chemical structure possessing potent, specific biological activity is very low. These experimental findings are supported by the current imderstanding of the way in which small molecules interact with proteins to bring about biomolecular activity. 

Jones CG, Firn RD. (1991). On the evolution of plant secondary chemical diversity. The Philosophical Transactions of the Royal Society, 333, 273-80. Despite the overwhelming evidence that most NPs possess no potent, specific biological activity, NP researchers often imply the opposite by using generalisations that imply the opposite. For example, leaf alkaloids... 

A discussion on how to derive a QSAR regression equation is beyond the scope of this chapter. However, in addition to the paper by Grogan et al. [8], a number of books are available on QSAR, and most provide many different descriptors and QSAR regression equations that correlate the specific biological activities (e.g., acute toxicity) of various classes of substances with physicochemical properties. Books that are more suited for the beginner are listed in the reference section [63-66]. The reader is encouraged to examine these books for detailed discussions on the development and applications of QSAR equations. 

It then clearly appeared that complete knowledge of the primary structure and conformation of the glycans was necessary, first, to establish the relationships between structure and specific biological activity, and second, to explain the pathogenesis of the glycoprotein-... 

The high toxicity and specific biological activity of 1-arylsilatranes was discovered about 15 years ago1, 2 At that time, these substances belonged to an almost unknown class of heterocyclic derivatives of 5-coordinate silicon with general formula I (Fig. 1). 

The importance of these three classes of unsaturated compounds is that they contain many naturally occurring examples having specific biological activity. For this reason their general methods of synthesis are of interest. Furthermore, their particular functional features are to be found embedded in the structures of more complex acyclic, alicyclic and polycyclic molecules. Thus the incorporation of the simpler structures as building blocks in multistage syntheses of, for example, antibiotics has been one of the synthetic challenges of recent decades. 

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