Condensed tannins extracted from European softwood bark are recognized as alternatives to synthetic phenolics. The extraction is generally performed in hot water, leading to simultaneous extraction of other bark constituents such as carbohydrates, phenolic monomers and salts. Characterization of the extract's composition and identification of the extracted tannins' molecular structure are needed to better identify potential applications. Bark from Silver fir (Abies alba [Mill.]), European larch (Larix decidua [Mill.]), Norway spruce (Picea abies [Karst.]), Douglas fir (Pseudotsuga menziesii [Mirb.]) and Scots pine (Pinus sylvestris [L.]) were extracted in water at 60°C. The amounts of phenolic monomers, condensed tannins, carbohydrates, and inorganic compounds in the extract were determined. The molecular structures of condensed tannins and carbohydrates were also investigated (HPLC-UV combined with thiolysis, MALDI-TOF mass spectrometry, anion exchange chromatography). Distinct extract compositions and tannin structures were found in each of the analysed species. Procyanidins were the most ubiquitous tannins. The presence of phenolic glucosides in the tannin oligomers was suggested. Polysaccharides such as arabinans, arabinogalactans and glucans represented an important fraction of all extracts. Compared to traditionally used species (Mimosa and Quebracho) higher viscosities as well as faster chemical reactivities are expected in the analysed species. The most promising species for a bark tannin extraction was found to be larch, while the least encouraging results were detected in pine. A better knowledge of the interaction between the various extracted compounds is deemed an important matter for investigation in the context of industrial applications of such extracts.
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http://dx.doi.org/10.1016/j.phytochem.2015.10.006 | DOI Listing |
Plant Foods Hum Nutr
January 2025
Qinghai Provincial Key Laboratory of Tibetan Medicine Research and CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Science, Xining, 810008, P.R. China.
NAFLD is one of the most common and rapidly increasing liver diseases. Procyanidin C1 and procyanidin C2, B-type trimeric procyanidins, show beneficial effects on regulating lipid metabolism. However, the mechanism underlying these effects remain elusive.
View Article and Find Full Text PDFFood Chem X
January 2025
Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, Braga, Portugal.
This study used integrative omics to address the response of key elements of the grapevine holobiont to contrasted pedoclimatic conditions found in distinct subregions of Douro Valley (Portugal). A metabolic OPLS-DA model predicted with 100 % accuracy the geographic origin of berries; higher UV radiation, higher temperature and lower precipitation stimulated the accumulation of phenolic acids, flavonols and malvidin conjugates, in detriment of amino acids, organic acids, flavan-3-ols, proanthocyanidins and non-malvidin anthocyanins. Metabarcoding showed a trade-off between bacteria and fungal diversity among subregions, with , and acting as intraregional microbial markers.
View Article and Find Full Text PDFFront Bioeng Biotechnol
January 2025
Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Rostock, Germany.
This study investigates the mechanical properties as well as and cyto- and biocompatibility of collagen membranes cross-linked with glutaraldehyde (GA), proanthocyanidins (PC), hexamethylendiisocyanate (HMDI) and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EC/NHS). A non-crosslinked membrane was used as reference control (RF). The initial cytotoxic analyses revealed that the PC, EC, and HMDI crosslinked membranes were cytocompatible, while the GA crosslinked membrane was cytotoxic and thus selected as positive control in the further study.
View Article and Find Full Text PDFFront Microbiol
January 2025
School of Life Sciences, Anhui Medical University, Hefei, Anhui, China.
Background: Obesity and high fasting blood glucose (FBG) resulting from high-fat diets (HFDs) have emerged as significant public health concerns, garnering increasing attention. Recently, gut microbiota has been linked with metabolic diseases such as type 2 diabetes (T2DM), and its mediating role in dietary supplements has been confirmed. Seeking various dietary supplements to lose body weight (BW) and decrease FBG and explaining the underlying mechanism have become the research hotspots in T2DM studies.
View Article and Find Full Text PDFPlant Foods Hum Nutr
January 2025
Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Qro., 76010, México.
Grape pomace (GP) is a by-product rich in phytochemicals, including extractable polyphenols (EPPs) and non-extractable polyphenols (NEPPs), which have distinct metabolic fates that may affect their biological activities. The benefits of GP have been reported in relation to obesity and its comorbidities, particularly when administered preventively focusing on EPPs. Therefore, the aim of this study was to investigate the effects of EPPs and NEPPs from GP as a treatment for obesity and its associated metabolic alterations.
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