{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T23:19:16Z","timestamp":1769642356566,"version":"3.49.0"},"reference-count":68,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T00:00:00Z","timestamp":1557360000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Latvian-France collaboration programme \u201cOSMOZE\u201d","award":["OSMOZE"],"award-info":[{"award-number":["OSMOZE"]}]},{"name":"The Latvian State Institute of Wood Chemistry Bioeconomy grant &quot;LigProBK&quot;","award":["LigProBK"],"award-info":[{"award-number":["LigProBK"]}]},{"DOI":"10.13039\/501100001824","name":"Czech Science Foundation","doi-asserted-by":"publisher","award":["P208\/12\/G016"],"award-info":[{"award-number":["P208\/12\/G016"]}],"id":[{"id":"10.13039\/501100001824","id-type":"DOI","asserted-by":"publisher"}]},{"name":"The Ministry of Education, Youth and Sports of the Czech Republic","award":["Project LO1305"],"award-info":[{"award-number":["Project LO1305"]}]},{"name":"The student project IGA_PrF_2017_028 of Palacky University","award":["IGA_PrF_2017_028"],"award-info":[{"award-number":["IGA_PrF_2017_028"]}]},{"name":"The CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679, financed by national funds through the FCT\/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement","award":["FCT Ref. UID\/CTM\/50011\/2013"],"award-info":[{"award-number":["FCT Ref. UID\/CTM\/50011\/2013"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The valorization of lignins as renewable aromatic feedstock is of utmost importance in terms of the use of sustainable resources. This study provides a deductive approach towards market-oriented lignin-derived antioxidants by ascertaining the direct effect of different structural features of lignin on the reactivity of its phenolic OH groups in the radical scavenging reactions. The antioxidant activity of a series of compounds, modeling lignin structural units, was experimentally characterized and rationalized, using thermodynamic descriptors. The calculated O\u2013H bond dissociation enthalpies (BDE) of characteristic lignin subunits were used to predict the modification pathways of technical lignins. The last ones were isolated by soda delignification from different biomass sources and their oligomeric fractions were studied as a raw material for modification and production of optimized antioxidants. These were characterized in terms of chemical structure, molecular weight distribution, content of the functional groups, and the antioxidant activity. The developed approach for the targeted modification of lignins allowed the products competitive with two commercial synthetic phenolic antioxidants in both free radical scavenging and stabilization of thermooxidative destruction of polyurethane films.<\/jats:p>","DOI":"10.3390\/molecules24091794","type":"journal-article","created":{"date-parts":[[2019,5,9]],"date-time":"2019-05-09T08:19:59Z","timestamp":1557389999000},"page":"1794","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":39,"title":["Lignin Modification Supported by DFT-Based Theoretical Study as a Way to Produce Competitive Natural Antioxidants"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0169-3027","authenticated-orcid":false,"given":"Liga","family":"Lauberte","sequence":"first","affiliation":[{"name":"Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006 Riga, Latvia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9272-1918","authenticated-orcid":false,"given":"Gabin","family":"Fabre","sequence":"additional","affiliation":[{"name":"INSERM UMR 1248, Universit\u00e9 de Limoges, Facult\u00e9 de Pharmacie, 2 rue du Docteur Marcland, 87025 Limoges Cedex, France"}]},{"given":"Jevgenija","family":"Ponomarenko","sequence":"additional","affiliation":[{"name":"Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006 Riga, Latvia"}]},{"given":"Tatiana","family":"Dizhbite","sequence":"additional","affiliation":[{"name":"Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006 Riga, Latvia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6304-5105","authenticated-orcid":false,"given":"Dmitry V.","family":"Evtuguin","sequence":"additional","affiliation":[{"name":"CICECO\/University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Galina","family":"Telysheva","sequence":"additional","affiliation":[{"name":"Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006 Riga, Latvia"}]},{"given":"Patrick","family":"Trouillas","sequence":"additional","affiliation":[{"name":"INSERM UMR 1248, Universit\u00e9 de Limoges, Facult\u00e9 de Pharmacie, 2 rue du Docteur Marcland, 87025 Limoges Cedex, France"},{"name":"Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palack\u00fd University, t\u0159. 17 listopadu 12, 771 46 Olomouc, Czech Republic"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1016\/j.rser.2017.01.030","article-title":"Producing jet fuel from biomass lignin: Potential pathways to alkyl-benzenes and cycloalkanes","volume":"72","author":"Cheng","year":"2017","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Hou, Q., Ju, M., Li, W., Liu, L., Chen, Y., Yang, Q., Hou, Q., Ju, M., Li, W., and Liu, L. (2017). Pretreatment of Lignocellulosic Biomass with Ionic Liquids and Ionic Liquid-Based Solvent Systems. Molecules, 22.","DOI":"10.3390\/molecules22030490"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1175","DOI":"10.1039\/C5GC02616D","article-title":"Towards lignin-based functional materials in a sustainable world","volume":"18","author":"Kai","year":"2016","journal-title":"Green Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4816","DOI":"10.1039\/C4GC01160K","article-title":"Targeted chemical upgrading of lignocellulosic biomass to platform molecules","volume":"16","author":"Luterbacher","year":"2014","journal-title":"Green Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1246843","DOI":"10.1126\/science.1246843","article-title":"Lignin valorization: improving lignin processing in the biorefinery","volume":"344","author":"Ragauskas","year":"2014","journal-title":"Science"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1181","DOI":"10.1016\/j.biortech.2017.08.169","article-title":"Kraft lignin biorefinery: A perspective","volume":"247","author":"Hu","year":"2018","journal-title":"Bioresour. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1146\/annurev.arplant.54.031902.134938","article-title":"L IGNIN B IOSYNTHESIS","volume":"54","author":"Boerjan","year":"2003","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.indcrop.2004.04.022","article-title":"Characterisation of structure-dependent functional properties of lignin with infrared spectroscopy","volume":"20","author":"Boeriu","year":"2004","journal-title":"Ind. Crops Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1016\/j.eurpolymj.2017.08.042","article-title":"Lignin inspired phenolic polyethers synthesized via ADMET: Systematic structure-property investigation","volume":"95","author":"Vlaminck","year":"2017","journal-title":"Eur. Polym. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/j.indcrop.2007.07.011","article-title":"Potential applications of antioxidant lignins from different sources","volume":"27","author":"Vinardell","year":"2008","journal-title":"Ind. Crops Prod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"6683","DOI":"10.1016\/j.biortech.2007.11.038","article-title":"Comparative antioxidant and cytotoxic effects of lignins from different sources","volume":"99","author":"UGARTONDO","year":"2008","journal-title":"Bioresour. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1979","DOI":"10.1016\/j.polymdegradstab.2012.03.009","article-title":"Effect of ligno-derivatives on thermal properties and degradation behavior of poly(3-hydroxybutyrate)-based biocomposites","volume":"97","author":"Bertini","year":"2012","journal-title":"Polym. Degrad. Stab."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"692","DOI":"10.1007\/s10924-013-0570-6","article-title":"Potential of Lignins as Antioxidant Additive in Active Biodegradable Packaging Materials","volume":"21","author":"Domenek","year":"2013","journal-title":"J. Polym. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1745","DOI":"10.1111\/j.1365-2621.1982.tb05029.x","article-title":"Antioxidant Properties of Lignin","volume":"47","author":"CATIGNANI","year":"1982","journal-title":"J. Food Sci."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Qazi, S., Li, D., Briens, C., Berruti, F., Abou-Zaid, M., Qazi, S.S., Li, D., Briens, C., Berruti, F., and Abou-Zaid, M.M. (2017). Antioxidant Activity of the Lignins Derived from Fluidized-Bed Fast Pyrolysis. Molecules, 22.","DOI":"10.3390\/molecules22030372"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2563","DOI":"10.1016\/j.carbpol.2011.11.041","article-title":"Lignin as additive in polypropylene\/coir composites: Thermal, mechanical and morphological properties","volume":"87","author":"Agnelli","year":"2012","journal-title":"Carbohydr. Polym."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1192","DOI":"10.1016\/j.polymdegradstab.2005.05.024","article-title":"Thermal and photochemical stability of poly(vinyl alcohol)\/modified lignin blends","volume":"91","author":"Fernandes","year":"2006","journal-title":"Polym. Degrad. Stab."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1016\/j.polymdegradstab.2005.01.052","article-title":"Thermal degradation behaviour of isotactic polypropylene blended with lignin","volume":"91","author":"Canetti","year":"2006","journal-title":"Polym. Degrad. Stab."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/0141-3910(95)87011-3","article-title":"Lignin inhibits autoxidative degradation of cellulose","volume":"49","author":"Schmidt","year":"1995","journal-title":"Polym. Degrad. Stab."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1080\/02773819708003119","article-title":"Antioxidant Properties of Phenolic Lignin Model Compounds","volume":"17","author":"Barclay","year":"1997","journal-title":"J. Wood Chem. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1016\/j.polymdegradstab.2005.02.007","article-title":"Stabilization effect of lignin in polypropylene and recycled polypropylene","volume":"89","year":"2005","journal-title":"Polym. Degrad. Stab."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"979","DOI":"10.1016\/j.ijbiomac.2017.08.102","article-title":"Aqueous acetone fractionation of kraft, organosolv and soda lignins","volume":"106","author":"Tamminen","year":"2018","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1016\/j.ijbiomac.2017.08.069","article-title":"Fractionation of lignin macromolecules by sequential organic solvents systems and their characterization for further valuable applications","volume":"106","author":"Park","year":"2018","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1515\/HF.2009.049","article-title":"Kraft lignin as feedstock for chemical products: The effects of membrane filtration","volume":"63","author":"Brodin","year":"2009","journal-title":"Holzforschung"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1016\/j.indcrop.2014.09.019","article-title":"Fractionation of five technical lignins by selective extraction in green solvents and characterisation of isolated fractions","volume":"62","author":"Boeriu","year":"2014","journal-title":"Ind. Crops Prod."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1139\/v95-081","article-title":"The heterogeneity of two Canadian kraft lignins","volume":"73","author":"Thring","year":"1995","journal-title":"Can. J. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1515\/hf.2011.089","article-title":"Solvent extraction as a means of preparing homogeneous lignin fractions","volume":"65","author":"Ropponen","year":"2011","journal-title":"Holzforschung"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1515\/hf.2010.023","article-title":"Fractionation, analysis, and PCA modeling of properties of four technical lignins for prediction of their application potential in binders","volume":"64","author":"Gosselink","year":"2010","journal-title":"Holzforschung"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.indcrop.2014.08.013","article-title":"Fractionation and characterization of industrial lignins","volume":"62","author":"Li","year":"2014","journal-title":"Ind. Crops Prod."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/S0141-3910(03)00057-0","article-title":"Antioxidant properties of lignin in polypropylene","volume":"81","author":"Pouteau","year":"2003","journal-title":"Polym. Degrad. Stab."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.indcrop.2004.01.003","article-title":"Structural modification of Kraft lignin after acid treatment: characterisation of the apolar extracts and influence on the antioxidant properties in polypropylene","volume":"21","author":"Pouteau","year":"2005","journal-title":"Ind. Crops Prod."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.indcrop.2017.03.039","article-title":"Aqueous organic solvent fractionation as means to improve lignin homogeneity and purity","volume":"103","author":"Mikkelson","year":"2017","journal-title":"Ind. Crops Prod."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.jaap.2012.12.023","article-title":"Fractionation of technical lignins as a tool for improvement of their antioxidant properties","volume":"103","author":"Arshanitsa","year":"2013","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2051","DOI":"10.15376\/biores.9.2.2051-2068","article-title":"Characterization of Softwood and Hardwood LignoBoost Kraft Lignins with Emphasis on their Antioxidant Activity","volume":"9","author":"Ponomarenko","year":"2014","journal-title":"BioResources"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1016\/j.ijbiomac.2017.03.015","article-title":"Fractionation of enzymatic hydrolysis lignin by sequential extraction for enhancing antioxidant performance","volume":"99","author":"An","year":"2017","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Brunow, G., Kilpel\u00e4inen, I., Sipil\u00e4, J., Syrj\u00e4nen, K., Karhunen, P., Set\u00e4l\u00e4, H., and Rummakko, P. (1998). Oxidative Coupling of Phenols and the Biosynthesis of Lignin. Lignin and Lignan Biosynthesis, American Chemical Society.","DOI":"10.1021\/bk-1998-0697.ch010"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1515\/HF.2003.039","article-title":"Inhomogeneities in the Chemical Structure of Hardwood Lignins","volume":"57","author":"Gellerstedt","year":"2003","journal-title":"Holzforschung"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5806","DOI":"10.1021\/jf0605392","article-title":"Organosolv Ethanol Lignin from Hybrid Poplar as a Radical Scavenger: Relationship between Lignin Structure, Extraction Conditions, and Antioxidant Activity","volume":"54","author":"Pan","year":"2006","journal-title":"J. Agric. Food Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"7659","DOI":"10.1039\/b904402g","article-title":"New aspects of the antioxidant properties of phenolic acids: a combined theoretical and experimental approach","volume":"11","author":"Anouar","year":"2009","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"13881","DOI":"10.1021\/jp906285b","article-title":"Free Radical Scavenging Properties of Guaiacol Oligomers: A Combined Experimental and Quantum Study of the Guaiacyl-Moiety Role","volume":"113","author":"Anouar","year":"2009","journal-title":"J. Phys. Chem. A"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2082","DOI":"10.1021\/jp3116319","article-title":"Free Radical Scavenging by Natural Polyphenols: Atom versus Electron Transfer","volume":"117","author":"Lemaur","year":"2013","journal-title":"J. Phys. Chem. A"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1841","DOI":"10.1007\/s00894-010-0893-3","article-title":"Lignin-derived oak phenolics: a theoretical examination of additional potential health benefits of red wine","volume":"17","author":"Setzer","year":"2011","journal-title":"J. Mol. Model."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/S0048-9697(00)00863-9","article-title":"Phenolic antioxidants in wood smoke","volume":"277","author":"Petersson","year":"2001","journal-title":"Sci. Total Environ."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1138","DOI":"10.1021\/jp066496+","article-title":"Density Functional Theory Study of the Conformational, Electronic, and Antioxidant Properties of Natural Chalcones","volume":"111","author":"Kozlowski","year":"2007","journal-title":"J. Phys. Chem. A"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1667\/RR0824.1","article-title":"Theoretical Investigation of the Formation of a New Series of Antioxidant Depsides from the Radiolysis of Flavonoid Compounds","volume":"168","author":"Kozlowski","year":"2007","journal-title":"Radiat. Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.foodchem.2009.05.010","article-title":"A new antioxidant from wild nutmeg","volume":"118","author":"Calliste","year":"2010","journal-title":"Food Chem."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1016\/j.foodchem.2009.04.115","article-title":"Formation of dehydrodiisoeugenol and dehydrodieugenol from the reaction of isoeugenol and eugenol with DPPH radical and their role in the radical scavenging activity","volume":"118","author":"Bortolomeazzi","year":"2010","journal-title":"Food Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1080\/02773810009349637","article-title":"pKa-Values of Guaiacyl and Syringyl Phenols Related to Lignin","volume":"20","author":"Ragnar","year":"2000","journal-title":"J. Wood Chem. Technol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1016\/S0003-2670(98)00418-8","article-title":"Dissociation constants of neutral and charged acids in methyl alcohol. The acid strength resolution","volume":"374","author":"Rived","year":"1998","journal-title":"Anal. Chim. Acta"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"5763","DOI":"10.1021\/jf060132x","article-title":"Structure\u2212DPPH\u2022 Scavenging Activity Relationships:\u2009 Parallel Study of Catechol and Guaiacol Acid Derivatives","volume":"54","author":"Stella","year":"2006","journal-title":"J. Agric. Food Chem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.talanta.2006.03.050","article-title":"Radical scavenging ability of polyphenolic compounds towards DPPH free radical","volume":"71","author":"Troncoso","year":"2007","journal-title":"Talanta"},{"key":"ref_52","first-page":"3","article-title":"1H NMR spectroscopy as a method for the identification of hydroxyl-containing lignin fragments","volume":"6","author":"Kanitskaja","year":"1987","journal-title":"Khimija Drev."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"191","DOI":"10.3183\/npprj-1994-09-03-p191-195","article-title":"A new method for the analysis of phenolic groups in lignins by \u02b9H NMR spectrometry","volume":"9","author":"Li","year":"1994","journal-title":"Nord. Pulp Pap. Res. J."},{"key":"ref_54","unstructured":"(2019, April 05). Irganox\u00ae 1010. Available online: https:\/\/worldaccount.basf.com\/en_GB\/welcome.html."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1068","DOI":"10.1016\/j.progpolymsci.2009.06.002","article-title":"Thermal stability and flame retardancy of polyurethanes","volume":"34","author":"Chattopadhyay","year":"2009","journal-title":"Prog. Polym. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2107","DOI":"10.1021\/ja01325a033","article-title":"A New Vanillin Synthesis","volume":"56","author":"Mottern","year":"1934","journal-title":"J. Am. Chem. Soc."},{"key":"ref_57","first-page":"120","article-title":"The synthesis of lignin models, containing.- \u03b2-ether bond","volume":"6","author":"Rab","year":"1968","journal-title":"For. J."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.3891\/acta.chem.scand.03-1358","article-title":"Aromatic Keto- and Hydroxy-polyethers as Lignin Models. II","volume":"3","author":"Erdtman","year":"1949","journal-title":"Acta Chem. Scand."},{"key":"ref_59","unstructured":"Zakis, G.F. (1994). Functional Analysis of Lignins and Their Derivatives, TAPPI Press."},{"key":"ref_60","unstructured":"Ab\u00e4cherli Alfred, D.F. (1998). Method for Preparing Alkaline Solutions Containing Aromatic Polymers 1998. (6,239,198), U.S. Patent."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.indcrop.2016.07.050","article-title":"Exploring the application potential of incompletely soluble organosolv lignin as a macromonomer for polyurethane synthesis","volume":"92","author":"Arshanitsa","year":"2016","journal-title":"Ind. Crops Prod."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1016\/j.foodchem.2005.05.042","article-title":"A DFT study of the reactivity of OH groups in quercetin and taxifolin antioxidants: The specificity of the 3-OH site","volume":"97","author":"Trouillas","year":"2006","journal-title":"Food Chem."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1054","DOI":"10.1021\/jp075814h","article-title":"Mechanism of the Antioxidant Action of Silybin and 2,3-Dehydrosilybin Flavonolignans: A Joint Experimental and Theoretical Study","volume":"112","author":"Trouillas","year":"2008","journal-title":"J. Phys. Chem. A"},{"key":"ref_64","unstructured":"(2010). Gaussian 09, Gausian, Inc."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1016\/j.foodchem.2006.02.007","article-title":"Radical scavenging activity of different floral origin honey and beebread phenolic extracts","volume":"101","author":"Venskutonis","year":"2007","journal-title":"Food Chem."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1016\/j.chroma.2005.10.037","article-title":"Size-exclusion chromatography of technical lignins in dimethyl sulfoxide\/water and dimethylacetamide","volume":"1102","author":"Ringena","year":"2006","journal-title":"J. Chromatogr. A"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"4252","DOI":"10.1021\/jf010315d","article-title":"Comprehensive study on the chemical structure of dioxane lignin from plantation Eucalyptus globulus wood","volume":"49","author":"Evtuguin","year":"2001","journal-title":"J. Agric. Food Chem."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"122","DOI":"10.15227\/orgsyn.052.0122","article-title":"Reduction of Ketones by Use of the Tosylhydrazone Derivatives: Androstan-17 b-ol","volume":"52","author":"Caglioti","year":"1972","journal-title":"Org. Synth."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/24\/9\/1794\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:50:24Z","timestamp":1760187024000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/24\/9\/1794"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,5,9]]},"references-count":68,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,5]]}},"alternative-id":["molecules24091794"],"URL":"https:\/\/doi.org\/10.3390\/molecules24091794","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,5,9]]}}}