Eintrag in der Universitätsbibliographie der TU Chemnitz
Volltext zugänglich unter
URN: urn:nbn:de:bsz:ch1-200900431
Mokhtar, Mohd Noriznan
Zimmermann, Wolfgang (Prof. Dr.) ; Platzer, Bernd (Prof. Dr.-Ing.) ; Sträter, Norbert (Prof. Dr.) (Gutachter)
Biocatalytic Production, Preparation and Characterization of Large-ring Cyclodextrins
Kurzfassung in englisch
Cyclodextrins (CD) are cyclic oligosaccharides composed of six to more than sixty glucose units. Large-ring cyclodextrins (LR-CD) are novel CD comprised of more than eight glucose units with cavity structures and sizes different from that of commercially available CD<sub>6</sub> – CD<sub>8</sub>. LR-CD may offer unique molecular recognition properties and can be produced biocatalytically from starch using cyclodextrin glucanotransferase (CGTase, E.C. 2.4.1.19) in a short reaction time. LR-CD were isolated from glucose, CD<sub>6</sub> – CD<sub>8</sub> and other compounds by complexation of CD<sub>6</sub> – CD<sub>8</sub> as well as precipitation techniques. The yield of LR-CD (degree of polymerization from 9 to 21) was optimized using central composite design. Addition of polar organic solvents to the synthesis resulted in higher yields of LR-CD. LR-CD composed of 9 to 21 glucose units were successfully separated using reversed-phase of ODS-AQ chromatography and normal-phase of polyamine II chromatography. Maintaining optimized reaction conditions aided in a high yield of CD<sub>9</sub>; it could be separated with reasonable yield using a single step of polyamine II chromatography. A co-grinding method helped to obtain higher solubilization levels of glibenclamide, vitamin A acetate and vitamin D<sub>3</sub> in CD<sub>13</sub>, CD<sub>10</sub> and CD<sub>11</sub>, respectively when compared to other CD. Vitamin K<sub>1</sub> was solubilized in distilled water with CD<sub>6</sub> – CD<sub>13</sub> using a co-precipitation method. When compared with other CD, CD<sub>9</sub> was seen to be the best solubilizer. The analysis of complexes using ESI MS showed spironolactone and glibenclamide complexed with CD<sub>9</sub> and CD<sub>13</sub>, respectively.
| Universität: | TU Chemnitz | |
| Institut: | Professur Technische Thermodynamik | |
| Fakultät: | Fakultät für Maschinenbau | |
| Dokumentart: | Dissertation | |
| URL/URN: | http://archiv.tu-chemnitz.de/pub/2009/0043 | |
| SWD-Schlagwörter: | Bacillus macerans , Molekulare Erkennung | |
| Freie Schlagwörter (Deutsch): | Large-ring cyclodextrins (LR-CD) , central composite design , co-grinding , co-precipitation , cyclodextrin glucanotransferase (CGTase) , host-guest complexation , molecular recognition , supramolecular chemistry | |
| DDC-Sachgruppe: | Biowissenschaften; Biologie | |
| Tag der mündlichen Prüfung | 26.01.2009 |
