Extraction of homogeneous lignin oligomers by ozonation of Miscanthus giganteus and vine shoots in a pilot scale reactor.

Lignin, a complex phenolic polymer crucial for plant structure, is mostly used as fuel but it can be harnessed for environmentally friendly applications. This article explores ozonation as a green method for lignin extraction from lignocellulosic biomass, aiming to uncover the benefits of the extracted lignin. A pilot-scale ozonation reactor was employed to extract lignin from Miscanthus giganteus (a grass variety) and vine shoots (a woody biomass). The study examined the lignin extraction and modification of the fractions and identified the generation of phenolic and organic acids. About 48 % of lignin was successfully extracted from both biomass types. Phenolic monomers were produced, vine shoots yielding fewer monomers than Miscanthus giganteus. Ozonation generated homogeneous lignin oligomers, although their molecular weight decreased during ozonation, with vine shoot oligomers exhibiting greater resistance to ozone. Extracted fractions were stable at 200 °C, despite the low molecular weight, outlining the potential of these phenolic fractions.

Chronic ingestion of a potential food contaminant induces gastrointestinal inflammation in rats: role of nitric oxide and mast cells.

Chronic ingestion of xenobiotics could be pathogenic in the gastrointestinal tract. Recently, we showed that acute low administration of a food contaminant (diquat) induced intestinal secretion involving mast cells and nitric oxide. This work aimed to determine in rats: (1) the influence of a low level (0.1 mg/kg/day per os) chronic ingestion of diquat on gastrointestinal immune cells, and (2) the participation of nitric oxide synthases (NOS) in these effects. Diquat increased both gastric and jejunal myeloperoxidase activities, tissue histamine in vitro release after stimulation by 48/80, and mast cell numbers. Diquat did not alter gastric NOS but increased intestinal inducible NOS (iNOS) activity. L-NAME prevented diquat-induced gastric and intestinal mastocytosis and gastric but not intestinal inflammation. L-NAME reduced gastric constitutive NOS (cNOS) activity and reestablished control iNOS activity. Chronic low level ingestion of diquat induces a low-grade gastric and intestinal inflammation with mastocytosis and enhancement of intestinal iNOS activity.

Quantification of isoflavones by capillary zone electrophoresis in soybean seeds: effects of variety and environment.

Soybean isoflavones (genistin, daidzin, glycitin, and their malonyl forms and aglucons) are thought to be responsible for the astringent taste of soyfoods. Generally, HPLC with a methanol and water elution gradient is used for isoflavone quantification, but capillary zone electrophoresis (CZE) has been used more recently to separate several flavonoids in plant extracts. We present the results of CZE analysis of isoflavones in soybean extracts. Conditions for separation by using CZE were optimized for analysis of soybean isoflavones. We compared the results of extraction at different temperatures and with different compositions of solvent. Total extraction of isoflavones was not affected by temperature but was affected by composition of the solvent. Malonyl forms of isoflavones were thermally unstable. We analyzed the isoflavone content of different varieties of soybean seeds sown on different dates. Total isoflavone content varied among different varieties and with sowing dates. Interactions between the variety and the sowing date also affected isoflavone composition. We conclude that the variety of soybean seed and environmental growing conditions, such as sowing date, can contribute to seed quality by reducing its isoflavone content, modifying its isoflavone composition, or both.