Abstract |
Novel polyrotaxane conjugates possessing side chains of protected amino acids, that is, N(α)-tert-butyloxycarbonylglycine (Boc-Gly) and N(α)-benzyloxycarbonylglycine ( Z-Gly), were successfully prepared via the carbonyldiimidazole-mediated esterification of hydroxyl groups in a polyrotaxane. The prepared conjugates were soluble in a wide variety of organic solvents, including N,N-dimethylacetamide, N,N-dimethylformamide, tetrahydrofuran, pyridine, and methanol. Thermogravimetric measurements of the conjugates showed three-step decomposition curves corresponding to the decompositions of the amino acid, poly( ethylene glycol) axis, and cyclodextrin rings. The Z-Gly- polyrotaxane conjugate showed a remarkable exotherm at 334 °C, together with a large weight loss. Treatment of the Boc-Gly- polyrotaxane conjugate with neat trifluoroacetic acid resulted in the complete removal of the Boc groups and gave a cationic polyrotaxane with many free primary amino groups, the amount of which was determined by colloidal titrations.
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Authors | Jun Araki, Keisuke Kagaya, Kousaku Ohkawa |
Journal | Biomacromolecules
(Biomacromolecules)
Vol. 10
Issue 7
Pg. 1947-54
(Jul 13 2009)
ISSN: 1526-4602 [Electronic] United States |
PMID | 19545123
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Amino Acids
- Colloids
- Formic Acid Esters
- Rotaxanes
- t-butyloxycarbonyl group
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Topics |
- Amino Acids
(chemistry)
- Colloids
- Drug Stability
- Formic Acid Esters
- Hot Temperature
- Rotaxanes
(chemical synthesis, chemistry)
- Solubility
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