Poly ethylenimine

Pd-Poly(ethylenimine), HC02H. This catalyst system was reported to be better than Pd/C or Pd black for Z removal. 

Anionic poly(amidoamine) (PAMAM) dendrimer was selected as a model of the soluble acidic-rich proteins to prepare CaC03 film on a poly(ethylenimine) film [49]. The CaCOj/polylethylenimine) composite film was obtained in the... 

Merkel OM, Librizzi D, Pfestroff A, Schurrat T, Buyens K, Sanders NN, De Smedt SC, Behe M, Kissel T (2009) Stability of siRNA polyplexes from poly(ethylenimine) and poly (ethylenimine)-g-poly(ethylene glycol) under in vivo conditions effects on pharmacokinetics and biodistribution measured by Fluorescence Fluctuation Spectroscopy and Single Photon Emission Computed Tomography (SPECT) imaging. J Control Release 138 148-159... 

BIOCLAIM A process for removing toxic metals from aqueous systems by use of bacteria supported on poly(ethylenimine) glutaraldehyde. 

Fig. 17. Chemical structures of anionic amphiphile sodium l,2-bis((tetradecyloxy)carbonyl) ethane-1-sulfonate (2Ci4SNa) and poly(ethylenimine)(PEI).

A modified poly(ethylenimine) also acts as an efficient catalyst for decarboxylation (Suh et al., 1976 Spetnagel and Klotz, 1976). In particular, the partially quaternized polymer [SS] catalyzed the decarboxylation of oxalacetic acid in a bifunctional manner (Spetnagel and Klotz, 1976), as shown in (18). The decarboxylation is thought to occur via pre-equilibrium... 

Godbey WT, Wu KK, Mikos AG (1999) Poly(ethylenimine) and its role in gene delivery. J Controlled Release 60 149-160... 

Deacylation rates of acetylsalicylate by isopropylated polymer at pH 7.3 were markedly slower than with unmodified polymer (Table III). With 2.4xlO-2 total residue molar concentration of isopropylated and unmodified poly(ethylenimine), respectively, k2, the pseudo-first-order rate for the former was 1.45 x 10-3 min-1, for the latter 1.2 x 10-1 min-1. Clearly, primary amines are the major sites for aminolysis of aspirin. 

As Fig. 15b illustrates, the graphical relation appears to be linear for an interaction number of 3 to 4, if A 1. Alternatively, for A = 1, linearity is evident (Fig. 15c) when the interaction number is 5 to 6. Thus a large value of A is compatible with the smallest interaction number. Excimer formation occurs within the fluorescence lifetime, about 8 nsec. Within that time the pyrene-labeled amine side chains must approach within about 4 A of each other. For the 5.3% pyrenylpolyethylenimine derivative in ethanol, where no ground-state association occurs, the effective local concentration of pyrene on the polymer matrix is about 10-2 M, as calculated from excimer fluorescence. In aqueous solution, where clusters form within the polymer matrix, the effective local concentration of pyrene adduct must be even greater. The quantitative assessment of fluorescence intensities (Fig. 15) points to a minimum interaction number of 3 to 4 pyrenyl-labeled amine side chains, within the 8 nsec lifetime. Since A 1, it appears from (12) that kDM(A) kMD + kD. Thus excimer formation must be very rapid in the polymer environment. We can conclude, therefore, that the primary-amine side chains of poly-ethylenimine are very flexible and mobile. 

It became of interest to see if we could obtain any indication of Schiff base formation with the polymer. Since spectroscopic probes would be obscured with the actual substrate, oxalacetate, because of the progress of the decarboxylation reaction (32), we have examined instead the spectra of oxalacetate-4-ethyl ester in solutions of the same modified poly-(ethylenimine) PEIQ—NH2. Such solutions develop a new absorption band at 290 nm. Furthermore, this band is essentially abolished if NaBH4 is added to the solution (Fig. 21). As is well known, NaBH4 reduces Schiff base linkages to amine groups.43-44... 

It has also been possible to confirm the presence of the reduction product of a Schiff base on the polymer by proton magnetic resonance. For this purpose we have used unmodified poly(ethylenimine), since it too catalyzes the decarboxylation of oxalacetate to its product, pyruvate. Unmodified polyethylenimine was mixed with oxalacetate-4-ethyl ester. One-half of this solution was treated with NaBH4 the second half was exposed to a similar environment but no NaBH4 was added. The borohydride-treated polymer exhibited a strong triplet in the nmr spectrum centered at 3.4 ppm upfield from the HOD resonance. This new feature would be expected from the terminal methyl protons of the oxalacetate ester attached to the polymer. Only a very weak triplet was found in the control sample not treated with borohydride. These observations are strong evidence for the formation of Schiff bases with the polymer primary amine groups. Evidently the mechanistic pathway for decarboxylation by the polymer catalyst is similar to that used enzymatically. 

Poly (ethylenimine) (PEI) has been demonstrated as an efficient gene delivery vehicle both in vitro and in vivo (161-163). Linear (22 kDa) and branched PEI formulations of varying molecular weights (0.6-800 kDa) have been reported. While polyplexes from higher molecular weight branched PEIs (70-800 kDa) were found to be more efficient in vitro but on intravenous administration the smaller and linear PEIs seem in general to be more efficient (171). However, questions as to the... 

The enzyme catalyzing the transfer of D-apiose from UDP-apiose to 4, 5-dihydroxyflavon-7-yl /3-D-glucopyranoside is commonly called apiin synthetase.7 Activity is measured by the formation of [14C]apiin from UDP-[U-14C]apiose. Apiin synthetase can be measured by the rapid separation and isolation, by poly(ethylenimine)-paper chromatography, of a product of the reaction, namely, [14C] apiin, from UDP-D-[U-14C]xylose and degradation products of UDP-[U-14C]apiose.31 There are reports of the isolation and purification of apiin synthetase from parsley leaves,31 from cell-suspension cultures of parsley,121 and from foxglove (Digitalis purpurea).31 Apiin synthetase isolated from parsley does not require metal ions, NAD+, or other cofactors, and is soluble. It is inhibited by several heavy metals, but not by tetra-N-... 

A recent investigation (79JOC4881) examining the effect of poly(ethylenimines) modified with 4-chloromethylimidazole on the hydrolysis of p-riitrophenyl caproate has shown that the rate actually decreases with increasing imidazole concentration, e.g. approximately a four-fold decrease when the imidazole concentration increased three-fold. This observation,... 

Oxazolidin-2-one (202) has been attached to poly(ethylenimine) (203) by Mannich reaction with formaldehyde (Scheme 97) (72NKK1179). The resultant polymer (204) was a... 

HYDROGENATION, CATALYSTS Nickel on alumina. Nickel-Graphite. Palladium-Poly(ethylenimine). Palladium catalysts. Raney nickel. Rhodium catalysts. 

Palladium(II) chloride-thiourea, 397 Palladium-poly(ethylenimine), 393 Pallescensin E, 144 (3-Panasinsene, 343, 344 Paniculide, 594-595 Parikh-Doering reagent, 216 Pentaalky (guanidines, 105 Pentacarbonyl(methoxyphenylcarbene)chromium (0), 397-401... 

Godbey, W.T., Wu, K.K. and Mikos, A.G. (1999) Tracking the intracellular path of poly(ethylenimine)/DNA complexes for gene delivery. Proc. Natl. Acad. Sci. USA, 96, 5177-5181. 

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