Ultrasonic-enhanced photocatalysis through piezoelectric and cavitation effects for lignin depolymerization.

Although a promising method for lignin depolymerization, photocatalysis faces the challenge of low efficiency. In this study, MoS2/ZnO heterojunction catalysts, endowed with piezocatalysis and photocatalytic capabilities, were crafted through Zn ion intercalation for the depolymerization of phenoxyphenylethanol (PP-ol) and alkali lignin. Then, the synergistic interplay between ultrasonic-induced piezoelectric fields and heterojunctions was analyzed. The amalgamation of the piezoelectric field and heterojunction in MoS2/ZnO catalysts resulted in a diminished photogenerated hole/electron recombination efficiency, thereby fostering the generation of ·OH during the reaction. This pivotal role of ·OH emerged as a crucial reactive substance, converting 95.8 % of PP-ol through ß-O-4 bond breaking within a 3-h treatment. By incorporating ultrasonic, the contact probability of PP-ol with the catalyst was significantly improved, resulting in efficient conversion even with a reduced amount of acetonitrile in the solvent system (20 %). Furthermore, ultrasonic-light methods show high efficiency for depolymerizing Alkali lignin (AL), with 33.2 % of lignin undergoing depolymerization in a 4-h treatment. This treatment simultaneously reduces the molecular weight of AL and cleaves numerous chemical bonds within it. Overall, this work presents a green approach to lignin depolymerization, providing insights into the synergistic action of ultrasonic and photocatalysis.

Lignin-ultrasound method: Enhancement of antimicrobial capacity of MoS2-containing films.

To improve the antimicrobial ability of MoS2-containing films, we used lignin and triple-frequency ultrasound for liquid-phase exfoliation (LPE) to obtain MoS2 nanosheets. Photoresponsive antimicrobial films with MoS2 nanosheets, lignin, polyvinyl alcohol and deep eutectic solvents were subsequently prepared. Lignin functionalized the MoS2 nanosheets by chemically linking with S in MoS2 and significantly improved the exfoliation efficiency. Tri-frequency ultrasound produces beneficial effects on the LPE process by creating a more homogeneous sound field and a stronger degree of cavitation. The concentration of MoS2 nanosheets in the exfoliating solution could reach 1.713 mg/mL under the effect of lignin-ultrasound. The antimicrobial ability of the films was analyzed, and the colony-forming units of E. coli and S. aureus could be reduced from 7 × 106 to 1 × 106 cfu/mL under the irradiation of infrared. The lignin in the film undergoes depolymerization and demethoxylation under the irradiation of infrared to have a more phenolic hydroxyl structure, which confers the growth inhibition ability of the films for bacteria that cannot be in close contact with the film. The method we used has some significance for the preparation of MoS2 nanosheets, and composite films prepared from MoS2, and lignin can be used in food packaging, wound antimicrobials, and other fields.

Green and sustainable extraction of lignin by deep eutectic solvent, its antioxidant activity, and applications in the food industry.

Lignin, an amorphous biomacromolecule abundantly distributed in the plant kingdom, has gained considerable attention due to its intrinsic bioactivities and renewable nature. Owing to its polyphenolic structure, lignin has a variety of human health activities, including antioxidant, antimicrobial, antidiabetic, antitumor, and other activities. The extraction of lignin from various sources in a green and sustainable manner is critical in the food industry. Deep eutectic solvent (DES) has recently been recognized as a class of safe and environmentally friendly media capable of efficiently extracting lignin. This article comprehensively reviews the recent advances in lignin extraction using DES, discusses the influential factors on the antioxidant activity of lignin, interprets the relationship between antioxidant activity and lignin structure, and overviews the applications of lignin in the food industry. We aim to highlight the advantages of DES in lignin extraction and valorization from the nutrition and food views.

Laccase-catalyzed lignin depolymerization in deep eutectic solvents: challenges and prospects.

Lignin has enormous potential as a renewable feedstock for depolymerizing to numerous high-value chemicals. However, lignin depolymerization is challenging owing to its recalcitrant, heterogenous, and limited water-soluble nature. From the standpoint of environmental friendliness and sustainability, enzymatic depolymerization of lignin is of great significance. Notably, laccases play an essential role in the enzymatic depolymerization of lignin and are considered the ultimate green catalysts. Deep eutectic solvent (DES), an efficient media in biocatalysis, are increasingly recognized as the newest and utmost green solvent that highly dissolves lignin. This review centers on a lignin depolymerization strategy by harnessing the good lignin fractionating capability of DES and the high substrate and product selectivity of laccase. Recent progress and insights into the laccase-DES interactions, protein engineering strategies for improving DES compatibility with laccase, and controlling the product selectivity of lignin degradation by laccase or in DES systems are extensively provided. Lastly, the challenges and prospects of the alliance between DES and laccase for lignin depolymerization are discussed. The collaboration of laccase and DES provides a great opportunity to develop an enzymatic route for lignin depolymerization.

Methylation- and homologous recombination deficiency-related mutant genes predict the prognosis of lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is a lung cancer subtype with poor prognosis. We investigated the prognostic value of methylation- and homologous recombination deficiency (HRD)-associated gene signatures in LUAD. METHODS: Data on RNA sequencing, somatic mutations, and methylation were obtained from TCGA database. HRD scores were used to stratify patients with LUAD into high and low HRD groups and identify differentially mutated and expressed genes (DMEGs). Pearson correlation analysis between DMEGs and methylation yielded methylation-associated DMEGs. Cox regression analysis was used to construct a prognostic model, and the distribution of clinical features in the high- and low-risk groups was compared. RESULTS: Patients with different HRD scores showed different DNA mutation patterns. There were 272 differentially mutated genes and 6294 differentially expressed genes. Fifty-seven DMEGs were obtained; the top 10 upregulated genes were COL11A1, EXO1, ASPM, COL12A1, COL2A1, COL3A1, COL5A2, DIAPH3, CAD, and SLC25A13, while the top 10 downregulated genes were C7, ERN2, DLC1, SCN7A, SMARCA2, CARD11, LAMA2, ITIH5, FRY, and EPHB6. Forty-two DMEGs were negatively correlated with 259 methylation sites. Gene ontology and pathway enrichment analysis of the DMEGs revealed enrichment of loci involved in extracellular matrix-related remodeling and signaling. Six out of the 42 methylation-associated DMEGs were significantly associated with LUAD prognosis and included in the prognostic model. The model effectively stratified high- and low-risk patients, with the high-risk group having more patients with advanced stage disease. CONCLUSION: We developed a novel prognostic model for LUAD based on methylation and HRD. Methylation-associated DMEGs may function as biomarkers and therapeutic targets for LUAD. Further studies are needed to elucidate their roles in LUAD carcinogenesis.