Structural characterization of the lignin of Cocos nucifera coir
The chemical structure of the lignin isolated from coconut coir has been comprehensively characterized in this work by analytical pyrolysis (Py-GC/MS), two-dimensional nuclear magnetic resonance (2D-NMR) and derivatization followed by reductive cleavage (DFRC). The analyses demonstrated that coconut...
| Autores: | , , , , , |
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| Tipo de recurso: | otro |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/86332 |
| Acceso en línea: | http://hdl.handle.net/10261/86332 |
| Access Level: | acceso abierto |
| Palabra clave: | Lignin Coir Cocos nucifera 2D NMR Py-GC/MS DFRC |
| Sumario: | The chemical structure of the lignin isolated from coconut coir has been comprehensively characterized in this work by analytical pyrolysis (Py-GC/MS), two-dimensional nuclear magnetic resonance (2D-NMR) and derivatization followed by reductive cleavage (DFRC). The analyses demonstrated that coconut coir lignin is a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin, with a predominance of G-lignin units (S/G 0.24), and with a considerable amount of associated p-hydroxybenzoates (13%). 2D-NMR indicated that the main substructures present in this lignin include β–O–4´ alkyl-aryl ethers, followed by phenylcoumarans (β–5´) and resinols (β–β´). In addition, 2D-NMR indicated that coconut coir lignin is partially acylated at the γ-carbon of the side-chain. DFRC results showed that acetates are one of the acylating group and preferentially acylate the γ-OH in syringyl rather than in guaiacyl units. |
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