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Hyperbranched 5,6-glucan as reducing sugar ball
| Title: | Hyperbranched 5,6-glucan as reducing sugar ball |
| Authors: | Tamaki, Masaki Browse this author | | Taguchi, Tsukasa Browse this author | | Nakabayashi, Soichi Browse this author | | Mori, Kota Browse this author | | Kitajyo, Yoshikazu Browse this author | | Sakai, Ryosuke Browse this author | | Kakuchi, Toyoji Browse this author | | Satoh, Toshifumi Browse this author |
| Issue Date: | Mar-2010 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Polymer Chemistry |
| Volume: | 1 |
| Issue: | 1 |
| Start Page: | 82 |
| End Page: | 92 |
| Publisher DOI: | 10.1039/b9py00223e |
| Abstract: | The ring-opening polymerization of 5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose (1) as a latent cyclic AB2-type monomer was carried out using potassium tert-butoxide (t-BuOK) or boron trifluoride diethyletherate (BF3・OEt2) as an initiator in order to synthesize a novel hyperbranched glycopolymer. The anionic and cationic polymerizations proceeded via the proton-transfer reaction mechanism to produce the hyperbranched poly(5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose) (2). In particular, the cationic polymerization with the slow-monomer-addition strategy is a facile method leading to the hyperbranched glycopolymers with high molecular weights and highly branched structures. The weight-average molecular weight (Mw,SEC-MALLs) values of 2 measured by multi-angle laser light scattering (MALLS) varied in the range from 7,400 to 122,400, which were significantly higher than the weight-average molecular weight (Mw,SEC) values determined by size exclusion chromatography (SEC). The intrinsic viscosities ([η]) of these polymers were very low in the range of 3.3-4.6 mL g^[-1] and the Mark-Houwink-Sakurada exponents α were calculated to be 0.08-0.27. These results of the MALLS, SEC, and viscosity measurements suggested that these polymers exist in a compact spherical conformation in solution because of their highly branched structure. The synthesis of the hyperbranched 5,6-glucan (3) by hydrolysis of polymer 2 was also demonstrated. Polymer 3 is a novel water-soluble hyperbranched glycopolymer arranged with numerous reducing D-glucose units on the peripheries of the polymer, and has a higher reducing ability than D-glucose because of the glycocluster effect or the multivalent effect of the reducing D-glucose units. Therefore, polymer 3 should be called a "reducing sugar ball". |
| Rights: | Polym. Chem., 2010, 1, 82-92 – Reproduced by permission of The Royal Society of Chemistry |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/44902 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 佐藤 敏文
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