{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T23:54:36Z","timestamp":1778802876141,"version":"3.51.4"},"reference-count":26,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2024,9,12]],"date-time":"2024-09-12T00:00:00Z","timestamp":1726099200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"USDA Specific Cooperative Agreement","award":["58-3064-2-002"],"award-info":[{"award-number":["58-3064-2-002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Plant secondary metabolites, including phenolics, represent a large quantity of organic material that enters soil and contributes to the formation of soil organic matter (SOM). The process of phenolics forming SOM remains poorly understood. One possible mechanism is oxidation of the phenolic compound catalyzed by redox active metals such as manganese (Mn) and iron (Fe) in soils. In this work, we report how three phenolic compounds react with a redox active environmentally relevant metal, Mn(IV). The reactions were monitored via nuclear magnetic resonance (NMR), high-performance liquid chromatography (HPLC), and direct CO2 measurements. Using these techniques, we demonstrate that gallic acid reacts with Mn(IV) less efficiently than pyrogallol. The products of the gallic acid:Mn(IV) reaction are more oxidized than the products of the pyrogallol reaction. Gallic acid produces small molecules and releases CO2, while pyrogallol produces a less oxidized product, likely a quinone, and releases less CO2. Benzoic acid did not react with Mn(IV). This work provides a framework for how different classes of plant secondary metabolites may be degraded abiotically by redox active metals in soil.<\/jats:p>","DOI":"10.3390\/molecules29184320","type":"journal-article","created":{"date-parts":[[2024,9,12]],"date-time":"2024-09-12T02:30:23Z","timestamp":1726108223000},"page":"4320","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Oxidation of Small Phenolic Compounds by Mn(IV)"],"prefix":"10.3390","volume":"29","author":[{"given":"Madeline G.","family":"Gruenberg","sequence":"first","affiliation":[{"name":"Department of Biochemistry and Molecular Biology, Wright State University, Dayton, OH 45435, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5201-3928","authenticated-orcid":false,"given":"Jonathan J.","family":"Halvorson","sequence":"additional","affiliation":[{"name":"Northern Great Plains Research Laboratory, United States Department of Agriculture\u2014Agricultural Research Service, Mandan, ND 58554, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6099-0382","authenticated-orcid":false,"given":"Ann E.","family":"Hagerman","sequence":"additional","affiliation":[{"name":"Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ikponmwosa G.","family":"Enoma","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Molecular Biology, Wright State University, Dayton, OH 45435, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-8494-3449","authenticated-orcid":false,"given":"Michael A.","family":"Schmidt","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Molecular Biology, Wright State University, Dayton, OH 45435, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1231","DOI":"10.3390\/nu2121231","article-title":"Chemistry and Biochemistry of Dietary Polyphenols","volume":"2","author":"Tsao","year":"2010","journal-title":"Nutrients"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1111\/j.1753-4887.1998.tb01670.x","article-title":"Polyphenols: Chemistry, dietary sources, metabolism, and nutritional significance","volume":"56","author":"Bravo","year":"1998","journal-title":"Nutr. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1007\/s10021-008-9173-9","article-title":"From genes to ecosystems: The genetic basis of condensed tannins and their role in nutrient regulation in a Populus model system","volume":"11","author":"Schweitzer","year":"2008","journal-title":"Ecosystems"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Linic, I., Samec, D., Gr\u00faz, J., Bok, V.V., Strnad, M., and Salopek-Sondi, B. (2019). Involvement of Phenolic Acids in Short-Term Adaptation to Salinity Stress is Species-Specific among Brassicaceae. Plants, 8.","DOI":"10.3390\/plants8060155"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1023\/A:1026206511084","article-title":"Tannins in nutrient dynamics of forest ecosystems\u2014A review","volume":"256","author":"Kraus","year":"2003","journal-title":"Plant Soil"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1858","DOI":"10.1007\/s11368-016-1375-8","article-title":"Environmental behaviors of phenolic acids dominated their rhizodeposition in boreal poplar plantation forest soils","volume":"16","author":"Wang","year":"2016","journal-title":"J. Soils Sediments"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1007\/s00374-011-0653-2","article-title":"Plant-borne flavonoids released into the rhizosphere: Impact on soil bio-activities related to plant nutrition. A review","volume":"48","author":"Cesco","year":"2012","journal-title":"Biol. Fertil. Soils"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s11104-009-0266-9","article-title":"Release of plant-borne flavonoids into the rhizosphere and their role in plant nutrition","volume":"329","author":"Cesco","year":"2010","journal-title":"Plant Soil"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/j.geoderma.2007.02.019","article-title":"Interactions between tannins and goethite- or ferrihydrite-coated quartz sand: Influence of pH and evaporation","volume":"139","author":"Kaal","year":"2007","journal-title":"Geoderma"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1002\/jpln.201700144","article-title":"Macronutrients and metals released from soils by solutions of naturally occurring phenols","volume":"180","author":"Schmidt","year":"2017","journal-title":"J. Plant Nutr. Soil Sci."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Alejandro, S., H\u00f6ller, S., Meier, B., and Peiter, E. (2020). Manganese in Plants: From Acquisition to Subcellular Allocation. Front. Plant Sci., 11.","DOI":"10.3389\/fpls.2020.00300"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"12136","DOI":"10.1021\/acs.est.1c00299","article-title":"A Critical Review on the Multiple Roles of Manganese in Stabilizing and Destabilizing Soil Organic Matter","volume":"55","author":"Li","year":"2021","journal-title":"Environ. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1007\/s10533-006-9050-6","article-title":"Litter decomposition rate is dependent on litter Mn concentrations","volume":"82","author":"Berg","year":"2007","journal-title":"Biogeochemistry"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"E5253","DOI":"10.1073\/pnas.1508945112","article-title":"Long-term litter decomposition controlled by manganese redox cycling","volume":"112","author":"Keiluweit","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1007\/s10533-010-9439-0","article-title":"Litter decomposition: What controls it and how can we alter it to sequester more carbon in forest soils?","volume":"101","author":"Prescott","year":"2010","journal-title":"Biogeochemistry"},{"key":"ref_16","first-page":"1934578X211069721","article-title":"A Brief Review of Phenolic Compounds Identified from Plants: Their Extraction, Analysis, and Biological Activity","volume":"17","author":"Zhang","year":"2022","journal-title":"Nat. Prod. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhao, Y.M., Lin, J., Quan, W.X., and Li, C.C. (2023). Distribution of six phenolic acids and soil nutrient relationships during litter decomposition in Rhododendron forests. Front. For. Glob. Chang., 6.","DOI":"10.3389\/ffgc.2023.1142510"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Rahman, A., Alam, M.U., Hossain, M.S., Mahmud, J.A., Nahar, K., Fujita, M., and Hasanuzzaman, M. (2023). Exogenous Gallic Acid Confers Salt Tolerance in Rice Seedlings: Modulation of Ion Homeostasis, Osmoregulation, Antioxidant Defense, and Methylglyoxal Detoxification Systems. Agronomy, 13.","DOI":"10.3390\/agronomy13010016"},{"key":"ref_19","first-page":"1934578X19874174","article-title":"A Role of Gallic Acid in Oxidative Damage Diseases: A Comprehensive Review","volume":"14","author":"Gao","year":"2019","journal-title":"Nat. Prod. Commun."},{"key":"ref_20","unstructured":"Halvorson, J., Jin, V., Liebig, M., Luciano, R., Hagerman, A., and Schmidt, M. (2024, August 08). Rapid Formation of Abiotic CO2 Results from Additions of a Simple Phenolic, Gallic Acid, to Soil. Authorea Preprints. Available online: https:\/\/d197for5662m48.cloudfront.net\/documents\/publicationstatus\/111169\/preprint_pdf\/ec4cf64b712d19c8e17566eb950a9a86.pdf."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"An, S., Wei, Y., Li, H., Zhao, Z., Hu, J., Philp, J., Ryder, M., Toh, R., Li, J., and Zhou, Y. (2022). Long-Term Monocultures of American Ginseng Change the Rhizosphere Microbiome by Reducing Phenolic Acids in Soil. Agriculture, 12.","DOI":"10.3390\/agriculture12050640"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Bao, L.M., Liu, Y.Y., Ding, Y.F., Shang, J.J., Wei, Y.L., Tan, Y., and Zi, F.T. (2022). Interactions Between Phenolic Acids and Microorganisms in Rhizospheric Soil from Continuous Cropping of Panax notoginseng. Front. Microbiol., 13.","DOI":"10.3389\/fmicb.2022.791603"},{"key":"ref_23","first-page":"683","article-title":"Liquid laccase production by Phomopsis liquidambari B3 accelerated phenolic acids degradation in long-term cropping soil of peanut","volume":"64","author":"Zhou","year":"2014","journal-title":"Acta Agric. Scand. Sect. B Soil Plant Sci."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Mudau, H.S., Mokoboki, H.K., Ravhuhali, K.E., and Mkhize, Z. (2022). Effect of Soil Type: Qualitative and Quantitative Analysis of Phytochemicals in Some Browse Species Leaves Found in Savannah Biome of South Africa. Molecules, 27.","DOI":"10.3390\/molecules27051462"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Inderjit (2005). Soil microorganisms: An important determinant of allelopathic activity. Plant Soil, 274, 227\u2013236.","DOI":"10.1007\/1-4020-4099-7_12"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2191","DOI":"10.3390\/molecules16032191","article-title":"Tannins of Constant Structure in Medicinal and Food Plants\u2014Hydrolyzable Tannins and Polyphenols Related to Tannins","volume":"16","author":"Okuda","year":"2011","journal-title":"Molecules"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/18\/4320\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:54:17Z","timestamp":1760111657000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/18\/4320"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,12]]},"references-count":26,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2024,9]]}},"alternative-id":["molecules29184320"],"URL":"https:\/\/doi.org\/10.3390\/molecules29184320","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,12]]}}}