Applying triplet-triplet annihilation upconversion in degradation of oxidized lignin model with good selectivity

2021 ◽  
pp. 133377
Author(s):  
Shanshan Liu ◽  
Heyuan Liu ◽  
Li Shen ◽  
Zuoxu Xiao ◽  
Yujia Hu ◽  
...  
2020 ◽  
Vol 16 ◽  
Author(s):  
Mahdieh Sharifi ◽  
Ramyakrishna Pothu ◽  
Rajender Boddula ◽  
Inamuddin

Background: There is a developing demand for innovation in petroleum systems replacements. Towards this aim, lignocellulosic biomass suggested as a possible sustainable source for the manufacturing of fuels and produced chemicals. The aims of this paper are to investigate different kinds of β-O-4 lignin model compounds for the production of value-added chemicals in presence of ionic liquids. Especially, a cheap β-O-4 lignin model Guaiacol glycerol ether (GGE) (Guaifenesin) is introduced to produce valuable chemicals and novel products. Methods: Research related to chemical depolymerization of lignocellulosic biomass activity is reviewed, the notes from different methods such as thermal and microwave collected during at least 10 years. So, this collection provides a good source for academic research and it gives an efficient strategy for the manufacturing of novel value-added chemicals at an industrial scale. Results: This research presented that ionic liquid microwave-assisted is a power saving, cost efficient, fast reaction, and clean way with high selectively and purity for production of high value chemicals rather that conversional heating. Guaiacol and catechol are some of these valuable chemicals that is produced from β-O-4 lignin model compounds with high word demands that are capable to produce in industry scale. Conclusion: The β-O-4 lignin model compounds such as Guaiacol glycerol ether (GGE) (Guaifenesin) are good platform for developing food materials, perfumery, biorefinery, and pharmaceutical industry by ionic liquids-assisted lignin depolymerization method.


2019 ◽  
Vol 96 ◽  
pp. 109286
Author(s):  
Abhishek Kumar ◽  
Luís Pinto da Silva ◽  
Joaquim C.G. Esteves da Silva ◽  
Kaushal Kumar

2019 ◽  
Vol 373 ◽  
pp. 190-200 ◽  
Author(s):  
Benjamin J. Hofmann ◽  
Reentje G. Harms ◽  
Sebastian P. Schwaminger ◽  
Robert M. Reich ◽  
Fritz E. Kühn

2021 ◽  
Vol 22 (5) ◽  
pp. 2629
Author(s):  
Dolores Linde ◽  
Iván Ayuso-Fernández ◽  
Marcos Laloux ◽  
José E. Aguiar-Cervera ◽  
Antonio L. de Lacey ◽  
...  

We aim to clarify the ligninolytic capabilities of dye-decolorizing peroxidases (DyPs) from bacteria and fungi, compared to fungal lignin peroxidase (LiP) and versatile peroxidase (VP). With this purpose, DyPs from Amycolatopsis sp., Thermomonospora curvata, and Auricularia auricula-judae, VP from Pleurotus eryngii, and LiP from Phanerochaete chrysosporium were produced, and their kinetic constants and reduction potentials determined. Sharp differences were found in the oxidation of nonphenolic simple (veratryl alcohol, VA) and dimeric (veratrylglycerol-β- guaiacyl ether, VGE) lignin model compounds, with LiP showing the highest catalytic efficiencies (around 15 and 200 s−1·mM−1 for VGE and VA, respectively), while the efficiency of the A. auricula-judae DyP was 1–3 orders of magnitude lower, and no activity was detected with the bacterial DyPs. VP and LiP also showed the highest reduction potential (1.28–1.33 V) in the rate-limiting step of the catalytic cycle (i.e., compound-II reduction to resting enzyme), estimated by stopped-flow measurements at the equilibrium, while the T. curvata DyP showed the lowest value (1.23 V). We conclude that, when using realistic enzyme doses, only fungal LiP and VP, and in much lower extent fungal DyP, oxidize nonphenolic aromatics and, therefore, have the capability to act on the main moiety of the native lignin macromolecule.


2021 ◽  
Author(s):  
Guangyong Liu ◽  
Qian Wang ◽  
Dongxia Yan ◽  
Yaqin Zhang ◽  
Chenlu Wang ◽  
...  

Cleavage of aryl ether (Caryl-O) bonds is crucial for conversion and value-added utilization of lignin and its derivatives, but remains extremely challenging under mild conditions due to strong Caryl-O linkages....


2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Qiaoqiao Ye ◽  
Tomoya Yokoyama

AbstractA non-phenolic C6-C2-type lignin model compound with the β-O-4 bond, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl)ethanol (I), was acidolyzed in aqueous 82% 1,4-dioxane containing HBr, HCl, or H2SO4 with a concentration of 0.2 mol/L at 85 ℃ to examine the differences between these acidolyses. Compound I primarily converted to an enol ether compound, 1-(2-methoxyphenoxy)-2-(3,4-dimethoxyphenyl)ethene (II), via the benzyl cation followed by acidolytic β-O-4 bond cleavage regardless of the acid-type, although the disappearance rates of compound I were remarkably different (HBr > HCl >> H2SO4). Acidolyses of compound II using these acids under the same conditions showed a similar tendency, but the rate differences were much smaller than in the acidolyses of compound I. Acidolyses of the α-methyl-etherified derivative of compound I (I-α-OMe) using these acids under the same conditions suggested that the formation rates of the benzyl cation from compound I-α-OMe (also from compound I) are not largely different between the acidolyses using these acids, but those of compound II from the benzyl cation are remarkably different. Acidolysis of the α-bromo-substituting derivative of compound I (I-α-Br) using HBr under the same conditions showed a characteristic action of Br¯ in the acidolysis. Br¯ adds to the benzyl cation generated from compound I or I-α-OMe to afford unstable compound I-α-Br, resulting in acceleration of the formation of compound II and of the whole acidolysis reaction.


Author(s):  
Ehsan Hamzehpoor ◽  
Cory Ruchlin ◽  
Yuze Tao ◽  
Jorge Eduardo Ramos-Sanchez ◽  
Hatem M. Titi ◽  
...  

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