Polyamines chemical structure

Fig. 7. Chemical structure of some cinnamic acid-polyamine conjugates.

FIGURE 5-14 Structures of some chemical species useful for designing anion-selective electrodes (a) Mn(III) porphyrin (b) vitamin Bi2 derivative (c) tri-n-octyltin chloride (d) lipophilic polyamine macrocyclic compound. 

In 1956 Brown, in a series of patents(68-75), disclosed that clays could be treated with di-, tri-, or tetra-substituted ammonia derivatives. Later, McLaughlin, et al.(76,77), introduced cationic polymers as permanent clay protective chemicals. A series of published results describing laboratory and field applications soon became available(78-81). Structural details of the cationic polymers appeared in patents(82-85). In general the polymers are polyamine derivatives, mostly quaternary in nature. Theng(86,87) has discussed how the multiple cationic centers in these polymers can interact and permanently protect clays. Callaway(88) et al. has noted that cationic polymers may interfere with the performance of crosslinked fracturing fluids. 

In contrast to the polycyclic indole, isoquinoline, or terpene alkaloids, the di- and polyamine alkaloids seem to be of much simpler construction. This first impression is misleading. Special structural features render this group of alkaloids even more difficult to handle than the above-mentioned ones. It should be noted that the structures of several polyamine alkaloids have had to be revised. Because of this, two main factors should be mentioned. (1) The alkaloids sometimes occur as mixtures that are very difficult to separate, and (2) the results from spectral or chemical analyses are equivocal (cf. references on structural elucidation in Section V). This group of alkaloids was the subject of several review papers (26-28) and especially covering the subject of synthesis (29-32). Some general aspects of the difficulties associated with the isolation and structure elucidation of the polyamine alkaloids are discussed. 

In contrast to extracts obtained from nature, which usually consist of a mixture of substances and are available only in very limited amounts, synthetic model systems have the advantages of controlled purity and good availability. Such systems enable the scientist to vary reaction parameters in a systematic fashion and to adjust individual functions to analyze their influence on the system. However, model systems should be as close as possible to the natural system. Therefore, we have undertaken a study to elucidate the chemical behavior of polyamine-silica systems, including not only polyamines which can be purchased, but also polyamines specifically synthesized, with structures as close as possible to the naturally occurring ones [11], Here, we report on investigations on the kinetics of silica condensation in the presence of various polyamines... 

To solve these problems, polyols with self-catalytic activity and of course with low volatility were created, using polyamines as starters [148-152]. These polyols, with an intrinsic catalytic activity, are chemically incorporated in the PU structure. As an immediate... 

Figure 3. Line- and space-filling structures of the polyamines putrescine, spermidine and spermine. With a little imagination, it is possible to envisage how the essentially linear paraquat molecule might fit into a transport system that has evolved to convey these chemicals into lung cells.

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