The effect of solvent composition on grafting gallic acid onto chitosan via carbodiimide.
Carbohydr Polym
; 140: 171-80, 2016 Apr 20.
Article
em En
| MEDLINE
| ID: mdl-26876841
ABSTRACT
The primary antioxidant (AOX) activity of chitosan can be introduced by grafting of phenolic compound - gallic acid (GA) to its amino and/or hydroxyl groups. The objective of this study was to investigate the effect of ethanol (EtOH) concentration (0%, 25%, 50%, and 75% in water) on efficiency of grafting GA onto chitosan in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-hydroxysuccinimide (NHS). The grafting was confirmed by FTIR and the efficiency was quantified as Folin's total phenolics. When pure deionized water was used as a sole solvent (0% EtOH), GA was grafted to chitosan at the largest extent (285.9mg GA/g chitosan). As the concentration of EtOH increased, the grafting efficiency proportionally decreased. NMR studies showed that EtOH inhibited grafting of GA by prohibiting the production of the intermediate - NHS ester. The results confirm that the concentration of EtOH in grafting solution significantly affects grafting efficiency of GA on chitosan.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Solventes
/
Carbodi-Imidas
/
Quitosana
/
Etanol
/
Ácido Gálico
Idioma:
En
Revista:
Carbohydr Polym
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos