Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan

Autor(es)

Facchinatto, William Marcondes ^[1] ; Garcia, Rodrigo Henrique dos Santos ^[1] ; Santos, Danilo Martins dos ^[2] ; Fiamingo, Anderson ^[3] ; Flores, Douglas William Menezes ^[4] ; Campana-Filho, Sergio Paulo ^[1] ; Azevedo, Eduardo Ribeiro de ^[3] ; Colnago, Luiz Alberto ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, Ave Trabalhador Sao Carlense 400, Caixa Postal 780, BR-13566590 Sao Carlos, SP - Brazil

^[2] Embrapa Instrumentat, Brazilian Corp Agr Res, Rua XV Novembro 1452, Caixa Postal 741, BR-13560970 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Sao Carlos Inst Phys, Ave Trabalhador Sao Carlense 400, Caixa Postal 369, BR-13566590 Sao Carlos, SP - Brazil

^[4] Univ Sao Paulo, Super Coll Agr Luiz de Queiroz, Ave Padua Dias 11, Caixa Postal 9, BR-13418900 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Carbohydrate Polymers; v. 256, MAR 15 2021.
• Citações Web of Science: 0

Resumo

Chitosans with different average degrees of acetylation and weight molecular weight were analyzed by time domain NMR relaxometry using the recently proposed pulse sequence named Rhim and Kessemeier Radio frequency Optimized Solid-Echo (RK-ROSE) to acquire H-1 NMR signal of solid-state materials. The NMR signal decay was composed of faster (tenths of mu s) and longer components, where the mobile-part fraction exhibited an effective relaxation transverse time assigned to methyl hydrogens from N-acetyl-D-glucosamine (GlcNAc) units. The higher intrinsic mobility of methyl groups was confirmed via DIPSHIFT experiments by probing the H-1-C-13 dipolar interaction. RK-ROSE data were modeled by using Partial Least Square (PLS) multivariate regression, which showed a high coefficient of determination (R-2 > 0.93) between RK-ROSE signal profile and average degrees of acetylation and crystallinity index, thus indicating that time-domain NMR consists in a promising tool for structural and morphological characterization of chitosan. (AU)

• Processo FAPESP: 16/09720-4 - Utilização de modelos de membrana para avaliar a biodegradabilidade de quitosanas
• Beneficiário: Anderson Fiamingo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/20973-4 - Nanofibras eletrofiadas coaxiais à base de quitosana para a liberação controlada de antibióticos e aplicações no tratamento de lesões periodontais
• Beneficiário: Danilo Martins dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/13656-8 - Desenvolvimento e aplicações da ressonância magnética nuclear em produtos e processos de interesse agropecuário
• Beneficiário: Luiz Alberto Colnago
• Modalidade de apoio: Auxílio à Pesquisa - Regular