Depolymerization of Lignin in Wood with Molecular Hydrogen Iodide
نویسنده
چکیده
Depolymerization of lignin in wood with hydrogen iodide in a nonpolar solvent is a selective, high-yield reaction that releases a diiodide of potential synthetic value into the solution. Finely milled wood (Douglas-fir, spruce, aspen, and sugarcane), was suspended in CDCl3 and treated with dry hydrogen iodide in a NMR tube. The yields and composition of the chloroform-soluble monomeric lignin depolymerization products, 1,3-diiodo-1-(4-hydroxyaryl)propanes, originated from guaiacyl (G), syringyl (S) and 4-hydroxyphenyl (H) units were assessed on a semi-quantitative basis. 1,3-Diiodoguaiacylpropane was the only product obtained from softwood whereas hardwood and grassy materials gave the mixtures of two (G, S) and three (G, S, H) products, respectively. This finding opens new avenues in utilization of wood wastes.
منابع مشابه
Conversion of milled pine wood by manganese peroxidase from Phlebia radiata.
Purified manganese peroxidase (MnP) from the white-rot basidiomycete Phlebia radiata was found to convert in vitro milled pine wood (MPW) suspended in an aqueous reaction solution containing Tween 20, Mn(2+), Mn-chelating organic acid (malonate), and a hydrogen peroxide-generating system (glucose-glucose oxidase). The enzymatic attack resulted in the polymerization of lower-molecular-mass, solu...
متن کاملLow-Power Microwave Radiation-assisted Depolymerization of Ethanol Organosolv Lignin in Ethanol/Formic Acid Mixtures
Ethanol organosolv lignin separated from bamboo was depolymerized by low-power microwave radiation (~80 W) using ethanol as a swelling agent and formic acid as a hydrogen donor solvent. After increasing the temperature from 100 to 200 °C, the total amount of phenolic compounds in the products increased from 8.1% to 40.8%, and both the weight average molecular weight (Mw) and number average mole...
متن کاملToward a better understanding of the lignin isolation process from wood.
The recently developed protocol for isolating enzymatic mild acidolysis lignins (EMAL) coupled with the novel combination of derivatization followed by reductive cleavage (DFRC) and quantitative (31)P NMR spectroscopy were used to better understand the lignin isolation process from wood. The EMAL protocol is shown to offer access at lignin samples that are more representative of the overall lig...
متن کاملOxidative Degradation of Wood by Brown-Rot Fungi
Brown-rot fungi are Basidiomycetes that remove cellulose and other polysaccharides from wood, leaving an amorphous, brown, crumbly residue that is composed largely of lignin, hence the name brown-rot. Decay by brown-rot fungi is by far the most serious type of damage to wood in-service. These fungi cause structural failure before losses in total wood substance are detected. The effect of brown-...
متن کاملDecay mechanisms of brown-rot fungi
Brown-rot fungi, e.g. the dryrot fungus (Serpula lacrymans), are the most harmful microorganisms in wood in service in Finland and in temperate regions. Brownrot fungi cause wood decay primarly by attacking the carbohydrates of the cell walls, leaving lignin essentially undigested. At the initial stage of the decay, the brown-rot fungi seem to operate by a mechanism which cause extensive change...
متن کامل