Guerra Anderson, Filpponen Ilari, Lucia Lucian A, Argyropoulos Dimitris S
Organic Chemistry of Wood Components Laboratory, Department of Forest Biomaterials Science & Engineering, North Carolina State University, Raleigh, North Carolina 27695-8005, USA.
J Agric Food Chem. 2006 Dec 27;54(26):9696-705. doi: 10.1021/jf062433c.
Milled wood lignin (MWL), cellulolytic enzyme lignin (CEL), and enzymatic mild acidolysis lignin (EMAL) were isolated from different wood species and characterized by various techniques. The EMAL protocol offered gravimetric lignin yields 2-5 times greater than those of the corresponding MWL and CEL. The purities of the EMALs were 3.75-10.6% higher than those of their corresponding CELs, depending upon the wood species from which they were isolated. Molecular weight analyses showed that the EMAL protocol isolates lignin fractions that are not accessed by the other procedures evaluated, while 31P NMR spectroscopy revealed that MWL is more condensed and bears more phenolic hydroxyl groups than EMAL and CEL. The yields and purities of EMAL, MWL, and CEL from hardwood were greater than those obtained for the examined softwoods. Structural details obtained by DFRC (derivatization followed by reductive cleavage)/31P NMR revealed different contents of condensed and uncondensed beta-O-aryl ether structures, dibenzodioxocins, and condensed and uncondensed phenolic hydroxyl and carboxylic acid groups within lignins isolated from different wood species.
从不同木材种类中分离出磨木木素（MWL）、纤维素分解酶解木素（CEL）和酶促温和酸解木素（EMAL），并采用多种技术对其进行表征。与相应的MWL和CEL相比，EMAL方法得到的木素重量产率高2至5倍。根据分离EMAL的木材种类不同，其纯度比相应的CEL高3.75%至10.6%。分子量分析表明，EMAL方法分离出的木素级分是其他评估方法无法得到的，而31P核磁共振光谱显示，MWL比EMAL和CEL缩合程度更高，且含有更多的酚羟基。阔叶材中EMAL、MWL和CEL的产率和纯度高于所研究针叶材中的相应值。通过衍生化后还原裂解/31P核磁共振（DFRC/31P NMR）获得的结构细节表明，从不同木材种类中分离出的木素中，缩合和未缩合的β-O-芳基醚结构、二苯并二恶英以及缩合和未缩合的酚羟基和羧酸基团的含量各不相同。
