{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,26]],"date-time":"2026-10-26T23:00:42Z","timestamp":1793055642394,"version":"4.5.0"},"reference-count":35,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,4,29]],"date-time":"2025-04-29T00:00:00Z","timestamp":1745884800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Polish Ministry of Science and Higher Education","award":["SUPB.RN.25.215"],"award-info":[{"award-number":["SUPB.RN.25.215"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>In this study, the voltammetric behavior of apocynin on a boron-doped diamond electrode in a phosphate buffer (pH 7.3) has been reported for the first time. The oxidation process is quasi-reversible, diffusion-controlled, and involves one electron and one proton. The product of the electrode reaction is an unstable radical that undergoes successive chemical transformations near the working electrode. The proposed mechanism of this process can be described as EqCi and served as the basis for the development of a new voltammetric method for determining apocynin in natural samples. The analytical signal was the anodic peak on DPV curves at a potential of 0.605 V vs. Ag\/AgCl. A linear response was observed in the concentration range of 0.213\u201327.08 mg L\u22121. The estimated LOD and LOQ values were 0.071 and 0.213 mg L\u22121, respectively. The effectiveness of the method was demonstrated both in control determinations and in the analysis of the dietary supplement. This procedure is simple, fast, sensitive, selective, and requires no complicated sample preparation, which is limited only to a simple extraction with ethanol. The low consumption of non-toxic reagents makes it environmentally friendly. To the best of our knowledge, this is the first presentation of a voltammetric procedure to determine this analyte studied in a phosphate buffer solution on a boron-doped diamond electrode. It can also be easily adapted to determine other phenolic compounds with antioxidant properties in various matrices.<\/jats:p>","DOI":"10.3390\/ma18092044","type":"journal-article","created":{"date-parts":[[2025,4,30]],"date-time":"2025-04-30T05:05:57Z","timestamp":1745989557000},"page":"2044","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Electroanalysis of Apocynin Part 2: Investigations on a Boron-Doped Diamond Electrode in Aqueous Buffered Solutions"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5333-9353","authenticated-orcid":false,"given":"Agata","family":"Skorupa","sequence":"first","affiliation":[{"name":"Institute of Chemistry, Jan Kochanowski University, 7 Uniwersytecka St., PL-25406 Kielce, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7016-5140","authenticated-orcid":false,"given":"Magdalena","family":"Jakubczyk","sequence":"additional","affiliation":[{"name":"Institute of Chemistry, Jan Kochanowski University, 7 Uniwersytecka St., PL-25406 Kielce, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5305-5967","authenticated-orcid":false,"given":"Slawomir","family":"Michalkiewicz","sequence":"additional","affiliation":[{"name":"Institute of Chemistry, Jan Kochanowski University, 7 Uniwersytecka St., PL-25406 Kielce, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2981","DOI":"10.2147\/DDDT.S176850","article-title":"Novel anti-inflammatory film as a delivery system for the external medication with bioactive phytochemical \u201cApocynin\u201d","volume":"12","author":"Anter","year":"2018","journal-title":"Drug Des. Dev. Ther."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"106507","DOI":"10.1155\/2008\/106507","article-title":"Apocynin: Molecular aptitudes","volume":"106507","author":"Stefanska","year":"2008","journal-title":"Mediat. Inflamm."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1007\/BF02493007","article-title":"Analysis of iridoid glycosides from Picrorhiza kurroa by capillary electrophoresis and high performance liquid chromatography-Mass spectrometry","volume":"53","author":"Sturm","year":"2001","journal-title":"Chromatographia"},{"key":"ref_4","first-page":"358","article-title":"Synthesis of apocynin dimer derivatives combining L-cysteine and alpha-lipoic acid","volume":"7","author":"Ou","year":"2017","journal-title":"J. Pharm. Biomed. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"221","DOI":"10.15406\/ppij.2019.07.00255","article-title":"Plants with evidence-based therapeutic effects against neurodegenerative diseases","volume":"7","author":"Gonzalez","year":"2019","journal-title":"Pharm. Pharmacol. Int. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.pmpp.2019.01.005","article-title":"Redox- and bio-activity of apocynin (acetovanillone) in tobacco, a plant phenolic that alleviates symptoms of autoimmune diseases in animals","volume":"106","author":"Baker","year":"2019","journal-title":"Physiol. Mol. Plant Pathol."},{"key":"ref_7","first-page":"137","article-title":"DFT study on the radical scavenging capacity of apocynin with different free radicals","volume":"49","author":"Yancheva","year":"2017","journal-title":"Bulg. Chem. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"112643","DOI":"10.1016\/j.bbr.2020.112643","article-title":"Apocynin as an antidepressant agent: In vivo behavior and oxidative parameters modulation","volume":"388","author":"Pereira","year":"2020","journal-title":"Behav. Brain Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Liu, Z., Ren, Z., Zhang, J., Chuang, C.C., Kandaswamy, E., Zhou, T., and Zuo, L. (2018). Role of ROS and nutritional antioxidants in human diseases. Front. Physiol., 9.","DOI":"10.3389\/fphys.2018.00477"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2821","DOI":"10.3390\/molecules18032821","article-title":"Apocynin: Chemical and biophysical properties of a NADPH oxidase inhibitor","volume":"18","author":"Zeraik","year":"2013","journal-title":"Molecules"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1038\/icb.2011.60","article-title":"Anti-inflammatory effects of apocynin, an inhibitor of NADPH oxidase, in airway inflammation","volume":"90","author":"Kim","year":"2012","journal-title":"Immunol. Cell Biol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Tomassi, A., Falegnami, A., and Romano, E. (2025). Talking Resilience: Embedded Natural Language Cyber-Organizations by Design. Systems, 13.","DOI":"10.3390\/systems13040247"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Y\u0131ld\u0131r\u0131m, B.A., Dogan, T., Bolat, \u0130., Ozcan, A.C., and Kocak, R. (2025). Effect of NADPH oxidase inhibitor apocynin on human lung cancer A549 cells via Bcl-2, Bax, caspase-3, and NF-\u03baB signaling pathway. Naunyn. Schmiedebergs. Arch. Pharmacol.","DOI":"10.1007\/s00210-025-03833-5"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"de Diego-Otero, Y., El Bekay, R., Garc\u00eda-Guirado, F., S\u00e1nchez-Salido, L., and Gir\u00e1ldez-P\u00e9rez, R.M. (2024). Apocynin, a Selective NADPH Oxidase (Nox2) Inhibitor, Ameliorates Behavioural and Learning Deficits in the Fragile X Syndrome Mouse Model. Biomedicines, 12.","DOI":"10.3390\/biomedicines12122887"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Vukovic, A., Karanovic, D., Mihailovic-Stanojevic, N.D., Miloradovic, Z., Brkic, P., Zivotic, M., Nesovic Ostojic, J., Ivanov, M., Kovacevic, S., and Vajic, U.J. (2024). Apocynin and Hyperbaric Oxygen Therapy Improve Renal Function and Structure in an Animal Model of CKD. Biomedicines, 12.","DOI":"10.3390\/biomedicines12122788"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Wang, K., Li, L., Song, Y., Ye, X., Fu, S., Jiang, J., and Li, S. (2013). Improvement of Pharmacokinetics Behavior of Apocynin by Nitrone Derivatization: Comparative Pharmacokinetics of Nitrone-Apocynin and its Parent Apocynin in Rats. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0070189"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.jpha.2016.08.001","article-title":"A stability-indicating high performance liquid chromatography method to determine apocynin in nanoparticles","volume":"7","author":"Ronik","year":"2017","journal-title":"J. Pharm. Anal."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1016\/j.jchromb.2015.01.025","article-title":"Pharmacokinetic, bioavailability, metabolism and plasma protein binding evaluation of NADPH-oxidase inhibitor apocynin using LC-MS\/MS","volume":"985","author":"Chandasana","year":"2015","journal-title":"J. Chromatogr. B Anal. Technol. Biomed. Life Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.nbd.2011.07.015","article-title":"Diapocynin and apocynin administration fails to significantly extend survival in G93A SOD1 ALS mice","volume":"45","author":"Trumbull","year":"2012","journal-title":"Neurobiol. Dis."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Michalkiewicz, S., Skorupa, A., Jakubczyk, M., and B\u0119bacz, K. (2024). Application of a Carbon Fiber Microelectrode as a Sensor for Apocynin Electroanalysis. Materials, 17.","DOI":"10.20944\/preprints202403.0726.v1"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Michalkiewicz, S., Skorupa, A., and Jakubczyk, M. (2021). Carbon materials in electroanalysis of preservatives: A review. Materials, 14.","DOI":"10.3390\/ma14247630"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.jelechem.2010.06.020","article-title":"Boron doped diamond electrode pre-treatments effect on the electrochemical oxidation of dsDNA, DNA bases, nucleotides, homopolynucleotides and biomarker 8-oxoguanine","volume":"648","author":"Oliveira","year":"2010","journal-title":"J. Electroanal. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1021\/jf072792n","article-title":"Dose formulation and analysis of diapocynin","volume":"56","author":"Luchtefeld","year":"2008","journal-title":"J. Agric. Food Chem."},{"key":"ref_24","unstructured":"Scholz, F. (2010). Electroanalytical Methods: Guide to Experiments and Applications, Springer."},{"key":"ref_25","unstructured":"Gosser, D.K. (1993). Cyclic Voltammetry, VCH Publishers, Inc.. Simulation and Analysis of Reaction Mechanisms."},{"key":"ref_26","unstructured":"Brett, C.M.A., and Oliveira Brett, M.A. (1993). Electrochemistry. Principles, Methods, and Applications, Oxford University Press."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1016\/j.electacta.2006.05.025","article-title":"Electrode passivation caused by polymerization of different phenolic compounds","volume":"52","author":"Ferreira","year":"2006","journal-title":"Electrochim. Acta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2399","DOI":"10.1016\/S0013-4686(02)00043-9","article-title":"Electrooxidation of 2,4-dichlorophenol and other polychlorinated phenols at a glassy carbon electrode","volume":"47","author":"Bustos","year":"2002","journal-title":"Electrochim. Acta"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/S0022-0728(97)00583-4","article-title":"Electrochemical quartz crystal microbalance investigation of surface fouling due to phenol oxidation","volume":"444","author":"Wang","year":"1998","journal-title":"J. Electroanal. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1006\/abio.2002.5577","article-title":"Mechanistic Study of the Oxidation of Caffeic Acid by Digital Simulation of Cyclic Voltammograms","volume":"303","author":"Hotta","year":"2002","journal-title":"Anal. Biochem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3508","DOI":"10.1002\/celc.202000924","article-title":"An Approach to the Electroanalysis of Electrode Passivating Analytes: The Determination of Phenol","volume":"7","author":"Wang","year":"2020","journal-title":"ChemElectroChem"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1002\/elan.201300150","article-title":"Presenting Analytical Performances of Electrochemical Sensors. Some Suggestions","volume":"25","author":"Desimoni","year":"2013","journal-title":"Electroanalysis"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1351\/pac199769020297","article-title":"A statistical overview of standard (IUPAC and ACS) and new procedures for determining the limits of detection and quantification: Application to voltammetric and stripping techniques","volume":"69","author":"Mocak","year":"1997","journal-title":"Pure Appl. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"811","DOI":"10.1021\/ar010066e","article-title":"Real-time electrochemical monitoring: Toward green analytical chemistry","volume":"35","author":"Wang","year":"2002","journal-title":"Acc. Chem. Res."},{"key":"ref_35","unstructured":"AOAC International (2025, April 27). Guidelines for Standard Method Performance Requirements AOAC Official Methods of Analysis. Appendix F, pp. 1\u201318. Available online: https:\/\/www.aoac.org\/wp-content\/uploads\/2019\/08\/app_f.pdf."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/9\/2044\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:24:31Z","timestamp":1760030671000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/9\/2044"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,29]]},"references-count":35,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,5]]}},"alternative-id":["ma18092044"],"URL":"https:\/\/doi.org\/10.3390\/ma18092044","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,29]]}}}