Applications of Molecular Spectroscopic Methods to the Elucidation of Lignin Structure

Lignin in plant cell wall is a complex amorphous polymer and is biosynthesized mainly from three aromatic alcohols, namely, p-coumaryl, coniferyl, and sinapyl alcohols. This biosynthesis process consists of mainly radical coupling reactions and creates a unique lignin polymer in each plant species. Generally, lignin mainly consists of p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) units and is linked by several types of carbon-carbon (β-β, β-5, β-1, and 5–5) and ether bonds. Due to the structural complexity, various molecular spectroscopic methods have been applied to unravel the aromatic units and different interunit linkages in lignin from different plant species. This chapter is focused on the application of ultraviolet (UV) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Fourier transform Raman (FT-Raman) spectroscopy, fluorescence spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy to lignin structural elucidation

Facile isothermal solid acid catalyzed ionic liquid pretreatments to enhance the combined sugars production from Arundo donax Linn.

Additional file 1. Enzymatic hydrolysis of raw and water pretreated A. donax. The raw samples were exposed to the same temperature profiles as that of IL-Amberlyst pretreatments. Data are means of three replicates. Ratio = digestibility IL-Amberlyst /digestibility hot water

Techno-economic analysis of geopolymer production from the coal fly ash with high iron oxide and calcium oxide contents

In this work, we firstly examined the technical feasibility of geopolymer synthesis from the coal fly ash with high iron oxide (48.84 wt.%) and calcium oxide (22.15 wt.%) contents. The heat resistance of geopolymer was represented by the dry weight loss which ranged from 2.5 to 4.9% and was better than that (11.7%) of OPC. However, the high iron oxide content made the acid resistance (13–14%) of geopolymer inferior to OPC. The economics of geopolymer production changes significantly upon the variation in the arrangement of material use and geopolymer price. The costs of Na2SiO3 and NaOH and the benefit of geopolymer selling were the major factors affecting the economic feasibility of geopolymer production. When the Na2SiO3 price was around 400 USD/ton, the geopolymer production will be profitable even if the geopolymer price was as low as 50 USD/ton. It is possible to improve the economics of geopolymer production by varying the arrangement of material use while not impairing the performance of geopolymer

Synteny analysis in Rosids with a walnut physical map reveals slow genome evolution in long-lived woody perennials.

BackgroundMutations often accompany DNA replication. Since there may be fewer cell cycles per year in the germlines of long-lived than short-lived angiosperms, the genomes of long-lived angiosperms may be diverging more slowly than those of short-lived angiosperms. Here we test this hypothesis.ResultsWe first constructed a genetic map for walnut, a woody perennial. All linkage groups were short, and recombination rates were greatly reduced in the centromeric regions. We then used the genetic map to construct a walnut bacterial artificial chromosome (BAC) clone-based physical map, which contained 15,203 exonic BAC-end sequences, and quantified with it synteny between the walnut genome and genomes of three long-lived woody perennials, Vitis vinifera, Populus trichocarpa, and Malus domestica, and three short-lived herbs, Cucumis sativus, Medicago truncatula, and Fragaria vesca. Each measure of synteny we used showed that the genomes of woody perennials were less diverged from the walnut genome than those of herbs. We also estimated the nucleotide substitution rate at silent codon positions in the walnut lineage. It was one-fifth and one-sixth of published nucleotide substitution rates in the Medicago and Arabidopsis lineages, respectively. We uncovered a whole-genome duplication in the walnut lineage, dated it to the neighborhood of the Cretaceous-Tertiary boundary, and allocated the 16 walnut chromosomes into eight homoeologous pairs. We pointed out that during polyploidy-dysploidy cycles, the dominant tendency is to reduce the chromosome number.ConclusionSlow rates of nucleotide substitution are accompanied by slow rates of synteny erosion during genome divergence in woody perennials

Research on the Stability of Pickering Emulsion and Its Application in Food Field

Pickering emulsions is a new emulsions system formed by replacing traditional emulsifiers with solid particles, which has some advantages such as strong stability, environmentally-friendly, high safety and so on. It has been highly favored in the fields of food, cosmetics, chemical materials and biomedicine. Based on the stability mechanism of Pickering emulsions, this review mainly discusses relevant factors affecting its stability from six aspects, including the type of solid particles, shape of solid particles, concentration of solid particles, surface charge of aqueous phase, volume fraction of oil-water phase and the wettability. Meanwhile, the achievements of domestic and overseas on Pickering emulsions are also summarized, including preparing the intelligent food films, preventing the lipid oxidation, delivering the bioactive substances, synthesizing the molecularly imprinted polymers, achieving biphasic catalysis, and constructing 4D printed food raw materials in recent years. This paper aims to provide theoretical basis and technical support to a certain extent for the diversified development of food industry and other related fields