Branched polyamines

Usually the acid-base properties of poly electrolyte are studied by potentiometric titrations. However it is well known, that understanding of polyelectrolyte properties in solution is based on the knowledge of the thermodynamic properties. Up to now, there is only a small number of microcalorimetry titrations of polyelectrolyte solutions published. Therefore we carried out potentiometric and microcalorimetric titrations of hydrochloric form of the linear and branched polyamines at 25°C and 65°C, to study the influence of the stmcture on the acid-base properties. 

Combination of amines and dendrimers functionalized proton scavenger resins efficiently removes excess reagents from amide-formation reactions. Marsh et al.41 used a supported branched polyamine and... 

Once DNA has been condensed by a polycation, it is important for these complexes to retain a certain level of stability in salt solutions to allow sufficient time for cellular uptake of the particles. Izumrudov et al. (1999) studied the stability of a variety of polymers including polyvinylpyridines, linear poly amines, branched polyamines, polymethacrylates, and polyamides in salt solutions at a variety of pHs. They observed that polymers with predominantly primary amines produced the most stable polymer/DNA complexes followed by tertiary then quaternary amines, while higher molecular weight polymers resulted in more stable complexes for all amine types. Thus, it may be possible to specifically control complex stability by adjusting the relative amount of each amine type in the polymer. 

Several authors describe distinct classes of chemical transfection reagents. Fischer et al. summarize synthesis methods, features, and applications of hyper-branched polyamines as carriers for nucleic acids. 

The construction of cascade molecules in a systematic divergent manner has its origins in the preparation of a series of branched polyamines more than a decade ago.1-3 Starting from a primary amine, each of the available hydrogens on nitrogen was replaced by an alkyl group... 

Niitsu, M., Samejima, K., Matsuzaki, S., and Hamana, K., Systematic analysis of naturally occurring linear and branched polyamines by gas chromatography and gas chromatography-mass spectrometry, J. Chromatogr., 641, 115-123, 1993. 

There is no known cure for prion disease however, optimism is offered by experimental observation that noncytotoxic dosages of branched polyamines cure prion-infected neuroblastoma cells in culture (Supattapone et al., 1999, 2001), apparently by rendering the aggregated protein to normal proteolytic process in the cell. 

Supattapone, S., WUle, H., Uyechi, L., Safar, J., Tremblay, P., Szoka, F., Cohen, F. E., Prusiner, S. B., and Scott, M. R. 2001. Branched polyamines cure prion-infected neuroblastoma cells. J. Vuol. 75 3453-3461... 

Problem 10.5 Like cyclic ethers, cyclic amines can be polymerized by ionic ring-opening method. Thus poly(ethyleneimine) can be prepared by the ring-opening polymerization of aziridine (see Table 10.1) with initiation by protonic acids followed by nucleophilic attack of the monomer. Account for the fact that the process gives rise to a branched polyamine and suggest a method by which the branching could be avoided to obtain a linear polyamine. 

Wan Jintao, Li Cheng, Bu Zhi-Yang, Xu Cun-Jin, Li Bo-Geng, and Fan Hong. A comparative study of epoxy resin cured with a linear diamine and a branched polyamine. Chem. Eng. J. 188 (2012) 160-172. 

We subjected the branched polyamine composite that was modified with chloroacetic acid, WP-2, to a similar analytical procedure. Here, we made the assumption that the tertiary amine residues in the polymer do not participate in bonding to the... 

Poly(ethyleneimine) Poly(ethyleneimine) is a branched polyamine (M = 1800) consisting of a 1 2 1 ratio of primary, secondary and tertiary amines that makes it structurally similar to polyamines isolated from S. tumis and C. Judformis [85]. These PEls were integrated as spherical reverse micelles (RMs) made from bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) in iso-octane, providing a constrained environment for silica precipitation. These RMs exchanged their contents... 

JOnsson accomplished the synthesis of branched polyamines using reductive amination together with a complex protecting strategy compris-... 

Yields dropped notably, when this procedure was applied to synthesize branched polyamines. This comes from the slow reduction rate of the tertiary amide that leads mainly to only partially reduced side products, even after 5 days at 65 °C. The problem was satisfactorily solved for ahphatic substituents by alkylating the secondary amine by reductive amination with aldehydes using NaBHAcs as an additional hydride source. 

Long-Chain and Branched Polyamines in Thermophilic Microbes... 

Polyamines are important, physiologically active substances in microbial cells. For thermophilic species, the intracellular concentrations of long-chain and branched polyamines are higher than in other organisms and are important for growth at high... 

Thermophiles (both bacterial and archaeal) produce two types of unusual polyamine long linear polyamines (e.g., caldopentamine [3333] and caldohexamine [33333]), and branched polyamines (e.g., tris-(3-aminopropyl)amine [3(3)3], N -aminopropylspermidine [3(3)4], tetrakis-(3-aminopropyl)ammonium [3(3)(3)3], and A -bis(aminopropyl) spermidine [3(3)(3)4]) (Fig. 12.1) (Oshima and Kawahata 1983 Hamana et al. 1992,1994). These polyamines are believed to have a role in thermal protection. 

Fig. 12.4 Effect of branched polyamines on translational activity, a Relative translation activity in the presence or absence of linear polyamines was examined in a cell-free protein synthesis system incorporating extracts from T. kodakarensis KCl (which lacks the gene for ChiAA4, a derivative of chitinase) at 80 °C for 90 min. Each branched polyamine was added to a reaction mixture. The relative amounts of synthesized ChiAA4 were measured as described in Eig. 12.3. b Structure and chain length of A -bis(aminopropyl)spermidine. c The speculated binding mode between branched-chain polyamines and tRNA loop regions. Circles indicate nucleotide unit...

Hamana K, Niitsu M, Matsuzaki S, Samejima K, Igarashi Y, Kodama T (1992) Novel linear and branched polyamines in the extremely thermophilic Eubacteria Thermoleophilum, Bacillus and... 

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