Synthesis Of Water-soluble Polymers Research Articles

Soluble and insoluble α-glucan synthesis in yeast by enzyme suites derived exclusively from maize endosperm.

Molecular mechanisms that distinguish the synthesis of semi-crystalline α-glucan polymers found in plant starch granules from the synthesis of water-soluble polymers by nonplant species are not well understood. To address this, starch biosynthetic enzymes from maize (Zea mays L.) endosperm were isolated in a reconstituted environment using yeast (Saccharomyces cerevisiae) as a test bed. Ninety strains were constructed containing unique combinations of 11 synthetic transcription units specifying maize starch synthase (SS), starch phosphorylase (PHO), starch branching enzyme (SBE), or isoamylase-type starch debranching enzyme (ISA). Soluble and insoluble branched α-glucans accumulated in varying proportions depending on the enzyme suite, with ISA function stimulating distribution into the insoluble form. Among the SS isoforms, SSIIa, SSIII, and SSIV individually supported the accumulation of glucan polymer. Neither SSI nor SSV alone produced polymers; however, synergistic effects demonstrated that both isoforms can stimulate α-glucan accumulation. PHO did not support α-glucan production by itself, but it had either positive or negative effects on polymer content depending on which SS or a combination thereof was present. The complete suite of maize enzymes generated insoluble particles resembling native starch granules in size, shape, and crystallinity. Ultrastructural analysis revealed a hierarchical assembly starting with subparticles of approximately 50 nm diameter that coalesce into discrete structures of approximately 200 nm diameter. These are assembled into semi-crystalline α-glucan superstructures up to 4 μm in length filling most of the yeast cytosol. ISA was not essential for the formation of such particles, but their abundance was increased dramatically by ISA presence.

Synthesis of Water-Dispersed Sulfobetaine Methacrylate-Iron Oxide Nanoparticle-Coated Graphene Composite by Free Radical Polymerization.

Research on the synthesis of water-soluble polymers has accelerated in recent years, as they are employed in many bio-applications. Herein, the synthesis of poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PSB) by free radical polymerization in a sonication bath is described. PSB and iron oxide nanoparticles (IONPs) were simultaneously stabilized on the graphene surface. Graphene surfaces with PSB (GPSB) and graphene surfaces with PSB and IONPs (GPSBI) were prepared. Since PSB is a water-soluble polymer, the hydrophobic nature of graphene surfaces converts to hydrophilic nature. Subsequently, the prepared graphene composites, GPSB and GPSBI, were well-dispersed in water. The preparation of GPSB and GPSBI was confirmed by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The impacts of PSB and IONPs on the graphene surfaces were studied systematically.

Bisindoles 33. Synthesis of water-soluble polymers having indole fragment in the polymer chain

Dimethylaminomethylation of polyamides and polyethers based on the di-acid chloride of .2, 2-dihydroxycarbonylbi (5-indolyl)oxide, and -sulfone, hexamethylenediamine, 4, 4'-diaminodiphenyloxide, and 2, 2-di(4hydroxy-3-chlorophenyl)propane has yielded gramine analogs which were converted into the corresponding water-soluble polyhydrochlorides, the preparation of sodium salts of several polyamides and polyamides containing indole fragments in the polymer chain is also described.

Synthesis of poly[N5-(2-hydroxyethyl)-L-glutamines] with modified side chain

The procedure for synthesis of water-soluble polymers on the basis of poly[N5-(2-hydroxyethyl)-L-glutamine] was developed. It allows binding of various groups of interest (reactive spacers, biologically active compounds, tracers etc.) to these polymers using side chains modifications. A multi-step procedure involves partial debenzylation of poly(γ-benzyl-L-glutamate), conversion of resulting carboxyl groups to reactive succinimido ester groups, which in turn are aminolyzed by the compound of interest. The final step of the synthesis, viz., aminolysis of residual benzyl ester groups with 2-aminoethanol, leads to water-soluble modified poly[N5-(2-hydroxyethyl)-L-glutamines].

Water-soluble poly(diazacrown ethers): evidence for a polymer-sandwich complex with barium

The synthesis of water-soluble polymers containing a [22] diazacrown ether in the backbone is described. These compounds are obtained by polycondensation of the cyclic diamine [22] with epichlorohydrin or diepoxyoctane. The cation binding properties of these polymers are studied by 13C n.m.r. spectroscopy and potentiometry, and the results compared with those of the monomeric analogues. The two polymers do not exhibit typical polyelectrolyte behaviour: each ligand unit in the chain is independent as far as basicity constants and stability of the complexes formed are concerned. In general, 1:1 complexes are observed in water with all the studied cations (Ca, Ba, Sr, Cu, Zn), except for the diepoxyoctane polymer where, in presence of barium, a 2:1 sandwich polymeric complex is obtained. By comparing with the other ligands studied, it is shown that this unique structure is due to the particular polymeric nature of this ligand.