红麻韧皮部和木质部纤维素酶木素的特性

Characterization of Cellulolytic Enzyme Lignins in Kenaf(Hibiscus Cannabinus L.)

用纤维素酶水解的方法从红麻韧皮部和木质部分离出红麻韧皮纤维素酶木素和红麻木质纤维素酶木素。通过元素分析、功能基含量测定以及碱性硝基苯氧化产物和酚酸的ＨＰＬＣ分析，ＩＲ，ＵＶ．＇Ｈ－ＮＭＲ和１３Ｃ－ＮＭＲ波谱分析，认为红麻韧皮纤维素酶木素属于ＧＳ型木素，其摩尔比为Ｇ：Ｓ＝１：１．８７，而红麻木质纤维素酶木素属于ＧＳＨ型，其摩尔比为Ｇ：Ｓ：Ｈ＝１：１．０３：Ｏ．２６。它们的Ｃ９单元式分别为Ｃ９Ｈ７．３８Ｏ３．４６（ＯＣＨ３）１．３４和Ｃ９Ｈ７．５２Ｏ３．００（ＯＣＨ３）１．２２。研究表明，在红麻韧皮纤维素酶木素中不存在酚酸酯或醚连接，而８１％的对香豆酸和９０％的阿魏酸可在红麻木质纤维素酶木素碱水解中除去，红麻木质纤维素酶木素比红麻韧皮纤维素酶木素缩聚度高。这两种纤维素酶木素的得率均高于７５％（占相应原料中Ｋｌａｓｏｎ木素含量），这无疑在木素研究中具有更好的代表性。

Cellulolytic enzyme lignins(CELs) were isolated from kenaf bast & core respectively. The lignins were characterized for their elemental composition, functional groups, HPLC of alkaline nitrobenzene oxidation products, and phenolic acids, IR, UV, 'H-NMR & 13C-NMR spectra as well as GC determinations of residual carbohydrate were also carried on.Results obtained indicate that the CEL of kenaf bast(CEL-KB) is GS-type lignin. similar to hardwoodlignin, with a molar ratio of G : S being 1 : 1.87, whereas the CEL of kenaf core(CEL-KC) is GSH -type lignin, similar to graminea lignin, with a molar ratio of G : S : H=1 : 1.03 : 0.26. The C9 formulas are calculated as C9H7.38O3.46(OCH3 )1.34 & C9H7.52O3.00(OCH3)1.22 for CEL-KB & CEL-KC respectively. A large amount of phenolic acids ester and /or ether linked with lignin were found in CEL-KC, but more in CEL-KB. The degree of condensation was higher in CEL-KC than in CEL-KB as confirmed by the presenceof phenolic hrdroxyle groups, total aldehydes & 'H-NMR spectra data. Besides, the higher yield of CEL prearation made it more representative of protolignin in the raw materials.