Molecular Composition of Soxhlet <i>N</i>‑Methyl-2-pyrrolidinone Extracts from a Lignite

<i>N</i>-Methyl-2-pyrrolidinone (NMP) is a capable solvent which could extract more substance from coals than any other solvents. However, the molecular composition of the extract was still unclear. In this study, a lignite was subjected to Soxhlet extraction using pyridine followed by NMP. The NMP extract and its hydrolyzed product were characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the NMP extract and its hydrolyzed product had very high nitrogen contents and N_<i>x</i>O_<i>y</i> class species with multiple nitrogen and oxygen atoms dominant in the detected species. Relative abundance of ¹⁵N isotope and the molecular composition of extracts obtained from different extraction conditions indicated that the NMP involved into the extracts. Both self-polymerization of NMP and chemical reactions between NMP and coals occurred in the thermal extraction

Significantly enriched KEGG pathways from PC1 to PC4.

<p>Significantly enriched KEGG pathways from PC1 to PC4.</p

Distribution of unigenes in the DF and MF of SA.

<p>The horizontal axis shows the length interval of the size of unigenes. The longitudinal axis shows the number of unigenes.</p

Linear regression analysis and column graphs of the gene expression between RNA-Seq sequencing and qRT-PCR.

<p>Linear regression analysis and column graphs of the gene expression between RNA-Seq sequencing and qRT-PCR.</p

Primer sequences for amplification of target and reference genes in two dwarf-form and medium-form <i>Sthenoteuthis oualaniensis</i>.

<p>Primer sequences for amplification of target and reference genes in two dwarf-form and medium-form <i>Sthenoteuthis oualaniensis</i>.</p

The number of unigenes annotated to TF families.

<p>The horizontal axis shows the name of the TF family. The longitudinal axis shows the number of unigenes classified into different TF families.</p

Directed acyclic graphs of PC1 to PC4.

<p>The branch shows the containment relationships of GO terms. The GO term with a deeper color represents more significant enrichment.</p

The number and percentage of GO annotated unigenes.

<p>The number and percentage of GO annotated unigenes.</p

Venn diagram illustrating the number of annotated unigenes in the DF and MF of SA.

<p>Venn diagram illustrating the number of annotated unigenes in the DF and MF of SA.</p

Eco-friendly Method for Efficient Conversion of Cellulose into Levulinic Acid in Pure Water with Cellulase-Mimetic Solid Acid Catalyst

Microcrystalline cellulose could be effectively converted into levulinic acid in pure water at 180 °C in 12 h without additives in a maximum yield of 51.5% with a cellulase-mimetic solid acid catalyst prepared without the use of sulfuric acid. Ball-milling pretreatment of cellulose improved levulinic acid yields by only a few percent, showing that the cellulose binding sites (−Cl) and catalytic sites (−SO₃H) of the catalyst are key to the activity of the catalyst. The spent catalyst could be regenerated with H₂O₂ solution after recycling for 5 times to maintain more than 95% of its catalytic activity. Glucose used as starting material under the same reaction conditions and with the same cellulase-mimetic solid acid gave a yield of 61.5% levulinic acid. The conversion route for carbohydrates to levulinic acid in pure water with the biomimetic catalyst prepared with a H₂SO₄-free method provides an environmentally friendly method for producing biobased-platform chemicals from renewable resources