Polyanions, chemical structures

Figure 1 Chemical structures of some amphipathic weak bases that have been loaded and stabilized in liposomes using trialkylammonium salts of polyanionic trapping agents in our lab. (A) Doxorubicin, (B) epirubicin, (C) vinorelbine, (D) vincristine, (E) vinblastine, (E) topotecan, (G) irinotecan, (H) swainsonine, (I) 2-diethylami-noethyl-ellipticinium, (J) 6-(3-aminopropyl)ellipticine, and (K) LAQ824.

Poly[(a-carboxymethyl)ethyl isocyanide] may be saponified with sodium hydroxide in methanol at room temperature in 5 days or at reflux in 20hrs, attended by discoloration. Aqueous solutions of the isolated salt do not show viscosities expected of polyanions. Attempt to isolate the free polycarboxylic acid by acidification is accompanied by decarboxylation, which is to be expected on the basis of its chemical structure (55). 

Keywords Antiviral activity Chemical structure Natural sulfated polysaccharides Polyanions Seaweeds... 

FIGURE 21.16 Sketch of the chemical structure of PEDOT-PSS with a doping level of -0.33. The PEDOT-chain is on the left-hand side and the polyanion PSS on the right-hand side. 

Fig. 2.4 a Schematic of the film deposition process using slides and beakers. Steps 1 and 3 represent the adsorption of a polyanion and polycation, respectively, and steps 2 and 4 are washing steps. The four steps are the basic buildup sequence for the simplest film architecture (A/ B) . The construction of more complex film architectures requires only additional beakers and a different deposition sequence, b Simplified molecular picture of the first two adsorption steps, depicting film deposition starting with a positively charged substrate. Counterions are omitted for clarity. The polyion conformation and layer interpenetration are an idealization of the surface charge reversal with each adsorption step, c Chemical structures of two t3q>ical polyions, the sodium salt of poly(styrene sulfonate) and poly(allylamine hydrochloride). Reproduced with kind permission of Ref. [32]... 

The structure of the large DNA molecule, which was known to be the main material of the chromosomes, remained a mystery until Watson and Crick proposed the double helix structure in 1953. Chromosomal (genomic) DNA consists oftwo complementary polyanionic chains made up of long sequences of four different nucleic bases. Since the four bases are complementary, the double stranded DNA molecule is capable of exact self-replication from either strand. The chemical structure of DNA is shown in Fig. 2.1. The diameter of the double helix is about 2 nm, while the length of the DNA polymer can be enormous, i.e., several centimeters in a putatively stretched out -state. Table 2.1 gives some comparisons for the size of DNA from different species. 

Figure 2 Left schematic molecular representation of polyelectrolyte multilayers. Center layer-by-layer electrostatic self-assembly films are alternately dipped in a polycation and a polyanion solution. A rinsing step follows every adsorption step. Right chemical structure of standard polyelectrolytes PAH and PSS.

Figure 2.21 Structure of polyanion [Au(0)(0H2)P2Wig06g] (46). Reprinted in part with permission from [7]. Copyright (2007) American Chemical Society.

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