- AutorIn
- Mohd Noriznan Mokhtar
- Titel
- Biocatalytic Production, Preparation and Characterization of Large-ring Cyclodextrins
- Zitierfähige Url:
- https://nbn-resolving.org/urn:nbn:de:bsz:ch1-200900431
- Datum der Einreichung
- 06.10.2008
- Datum der Verteidigung
- 26.01.2009
- Abstract (EN)
- 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.
- Freie Schlagwörter
- Large-ring cyclodextrins (LR-CD)
- central composite design
- co-grinding
- co-precipitation
- cyclodextrin glucanotransferase (CGTase)
- host-guest complexation
- molecular recognition
- supramolecular chemistry
- Klassifikation (DDC)
- 570
- Normschlagwörter (GND)
- Bacillus macerans
- Molekulare Erkennung
- GutachterIn
- Prof. Dr. Wolfgang Zimmermann
- Prof. Dr.-Ing. Bernd Platzer
- Prof. Dr. Norbert Sträter
- BetreuerIn
- Prof. Dr. Wolfgang Zimmermann
- Den akademischen Grad verleihende / prüfende Institution
- Technische Universität Chemnitz, Chemnitz
- URN Qucosa
- urn:nbn:de:bsz:ch1-200900431
- Veröffentlichungsdatum Qucosa
- 04.03.2009
- Dokumenttyp
- Dissertation
- Sprache des Dokumentes
- Englisch