Structural characterization of the bark and core lignins from kenaf (Hibiscus cannabinus)
authors Seca, AML; Cavaleiro, JAS; Domingues, FMJ; Silvestre, AJD; Evtuguin, D; Neto, CP
journal JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
author keywords lignin; kenaf; Hibiscus cannabinus; C-13 NMR; H-1 NMR; UV spectroscopy; FTIR spectroscopy; permanganate oxidation; phenolic acids
keywords MILLED WOOD LIGNIN; MACROMOLECULAR COMPONENTS; CHEMICAL-COMPOSITION; HYDROXYL-GROUPS; ARUNDO-DONAX; SPECTROSCOPY; POLYMER; WHEAT; PULP
abstract Dioxane and milled wood Lignins were isolated from the core and bark of kenaf (Hibiscus cannabinus), variety Salvador. These lignins were characterized by C-13 and H-1 NMR, FTIR, and UV spectroscopies, permanganate oxidation, and alkaline hydrolysis followed by GC and GC-MS analysis of the released products and by functional groups analysis. The permanganate oxidation and alkaline hydrolysis was also applied to "in situ" lignins. Isolated and "in situ" lignins showed significant differences in composition and structure. Strong structural differences were observed between bark and core lignins, suggesting their different biosynthetic routes. The beta-O-4 type linkages are the main interunit linkages and are more abundant in bark than in core lignin. The core lignin is more "condensed" and shows higher contents of beta-beta plus beta-5 Linkages than those in the bark lignin. Permanganate oxidation showed that both core and bark "in situ" lignins are HGS-type lignins with HGS proportions of 15:66:19 and 12:56:32, respectively (H including coumarate structures in the case of core lignin). Coumarates represent about 50% of the H units of core lignin and are absent in bark lignins. The presence of suberin-like aliphatic chains covalently bound to lignin was suggested for bark lignin.
publisher AMER CHEMICAL SOC
issn 0021-8561
year published 1998
volume 46
issue 8
beginning page 3100
ending page 3108
digital object identifier (doi) 10.1021/jf9801320
web of science category Agriculture, Multidisciplinary; Chemistry, Applied; Food Science & Technology
subject category Agriculture; Chemistry; Food Science & Technology
unique article identifier WOS:000075478100033
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 3.412
5 year journal impact factor 3.791
category normalized journal impact factor percentile 87.098
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg