{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T02:13:46Z","timestamp":1789524826161,"version":"build-2803163510"},"reference-count":48,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,11,28]],"date-time":"2025-11-28T00:00:00Z","timestamp":1764288000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003661","name":"Korea Institute for Advancement of Technology","doi-asserted-by":"crossref","award":["RS-2024-00409639"],"award-info":[{"award-number":["RS-2024-00409639"]}],"id":[{"id":"10.13039\/501100003661","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"crossref","award":["RS-2023-00281517"],"award-info":[{"award-number":["RS-2023-00281517"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antioxidants"],"abstract":"<jats:p>Objective: This study aimed to optimize the extraction of bioactive compounds from Polygonum cuspidatum Sieb. et Zucc. (P. cuspidatum) by evaluating the effect of ethanol concentration. Methods: Ultrasonic extraction was performed using ethanol concentrations of 0%, 30%, 50%, and 70%, and the resulting extracts were assessed for their chemical composition and multifunctional bioactivities. Results: The 70% Ethanol extract exhibited the highest total polyphenol and flavonoid contents and demonstrated the most potent antioxidant, enzyme-inhibitory, and antimicrobial activities, with significant differences (p &lt; 0.05) compared to other concentrations. Chemical analysis identified tannic acid, emodin, and a variety of phenolic compounds as the primary bioactive constituents. Structural analyses using Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared (FT-IR) Spectroscopy revealed that 70% Ethanol induced the most pronounced structural changes to the cell wall, while FT-IR analysis confirmed the presence of O-H, C=O, C=C, and C-O functional groups, providing a mechanistic basis for the superior extraction efficiency and bioactivity. Conclusions: Ethanol concentration is a critical determinant for maximizing the bioactivity of P. cuspidatum. Extraction with 70% ethanol is identified as the optimal condition, supporting the potential of this plant as a source of natural bioactive compounds.<\/jats:p>","DOI":"10.3390\/antiox14121431","type":"journal-article","created":{"date-parts":[[2025,11,28]],"date-time":"2025-11-28T12:14:16Z","timestamp":1764332056000},"page":"1431","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Optimizing Extraction Polarity for Multifunctional Bioactivities and Phenolic Composition in Polygonum cuspidatum Sieb. et Zucc. Ultrasonic Extraction"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2190-1433","authenticated-orcid":false,"given":"Yuchen","family":"Cheng","sequence":"first","affiliation":[{"name":"Department of Chemistry, Hannam University, Daejeon 34430, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Myat Pwint","family":"Phyu","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Hannam University, Daejeon 34430, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8724-7801","authenticated-orcid":false,"given":"Yuri","family":"Kang","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Hannam University, Daejeon 34430, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7191-238X","authenticated-orcid":false,"given":"Tao","family":"Lyu","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Hannam University, Daejeon 34430, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1787-8939","authenticated-orcid":false,"given":"Woonjung","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Hannam University, Daejeon 34430, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"105210","DOI":"10.1016\/j.jff.2022.105210","article-title":"The medicinal and aromatic plants as ingredients in functional beverage production","volume":"96","author":"You","year":"2022","journal-title":"J. Funct. Foods"},{"key":"ref_2","first-page":"317","article-title":"Research progress on chemical constituents in roots and rhizomes of Polygonum cuspidatum and their pharmacological activities","volume":"39","author":"Shi","year":"2016","journal-title":"Drug Eval. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1016\/j.jep.2013.05.007","article-title":"Botany, phytochemistry, pharmacology and potential application of Polygonum cuspidatum Sieb. et Zucc.: A review","volume":"148","author":"Peng","year":"2013","journal-title":"J. Ethnopharmacol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Wang, X., Hu, H., Wu, Z., Fan, H., Wang, G., Chai, T., and Wang, H. (2021). Tissue-specific transcriptome analyses reveal candidate genes for stilbene, flavonoid and anthraquinone biosynthesis in the medicinal plant Polygonum cuspidatum. BMC Genom., 22.","DOI":"10.1186\/s12864-021-07658-3"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1080\/13880209.2022.2158349","article-title":"Advances for pharmacological activities of Polygonum cuspidatum\u2014A review","volume":"61","author":"Ke","year":"2023","journal-title":"Pharm. Biol."},{"key":"ref_6","first-page":"641","article-title":"Separation and purification of the main components from Polygonum cuspidatum and their anti-hyperuricemia effect","volume":"19","author":"Li","year":"2021","journal-title":"Chin. J. Nat. Med."},{"key":"ref_7","first-page":"185","article-title":"Free radicals and their role in different clinical conditions: An overview","volume":"1","author":"Sarma","year":"2010","journal-title":"Int. J. Pharm. Sci. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1810","DOI":"10.1021\/np300392n","article-title":"Ultrasonic-assisted extraction of the botanical dietary supplement resveratrol and other constituents of Polygonum cuspidatum","volume":"75","author":"Chen","year":"2012","journal-title":"J. Nat. Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1016\/j.ultsonch.2016.06.035","article-title":"Ultrasound assisted extraction of food and natural products: Mechanisms, techniques, combinations, protocols and applications. A review","volume":"34","author":"Chemat","year":"2017","journal-title":"Ultrason. Sonochem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3254","DOI":"10.1557\/jmr.2019.144","article-title":"The study of ultrasound-assisted extraction of flavonoids from Polygonum cuspidatum Sieb. et Zucc","volume":"34","author":"Jia","year":"2019","journal-title":"J. Mater. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/S0021-9258(18)88697-5","article-title":"On phosphotungstic-phosphomolybdic compounds as color reagents","volume":"12","author":"Folin","year":"1912","journal-title":"J. Biol. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1016\/S0308-8146(98)00102-2","article-title":"The determination of flavonoid contents in mulberry and their scavenging effects on superoxide radicals","volume":"64","author":"Jia","year":"1999","journal-title":"Food Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1199","DOI":"10.1038\/1811199a0","article-title":"Antioxidant determinations by the use of a stable free radical","volume":"181","author":"Blois","year":"1958","journal-title":"Nature"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"832","DOI":"10.3746\/jkfn.2015.44.6.832","article-title":"Whitening and antioxidant activities of solvent extracts from hot-air dried Allium hookeri","volume":"44","author":"Jeong","year":"2015","journal-title":"J. Korean Soc. Food Sci. Nutr."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/S0076-6879(99)99037-7","article-title":"Screening of dietary carotenoids and carotenoid-rich fruit extracts for antioxidant activities applying ABTS radical cation decolorization assay","volume":"299","author":"Pellegrini","year":"1999","journal-title":"Methods Enzymol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"577","DOI":"10.3746\/jkfn.2012.41.5.577","article-title":"Antioxidant and antimicrobial activities of ethanol extract from six vegetables containing different sulfur compounds","volume":"41","author":"Kim","year":"2012","journal-title":"J. Korean Soc. Food Sci. Nutr."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1006\/abio.1996.0292","article-title":"The ferric reducing ability of plasma (FRAP) as a measure of \u201cantioxidant power\u201d: The FRAP assay","volume":"239","author":"Benzie","year":"1996","journal-title":"Anal. Biochem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.3746\/jkfn.2018.47.11.1076","article-title":"Antioxidant activity of fermented Kaempferia parviflora and inhibitory action against tyrosinase and elastase","volume":"47","author":"Choi","year":"2018","journal-title":"J. Korean Soc. Food Sci. Nutr."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"41","DOI":"10.5053\/ejobios.2010.4.0.6","article-title":"Screening of elastase and tyrosinase inhibitory activity from Jeju Island plants","volume":"4","author":"Moon","year":"2010","journal-title":"Eur. J. Biosci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2084","DOI":"10.1002\/jsfa.5585","article-title":"\u03b1-Glucosidase and \u03b1-amylase inhibitory activities of phlorotannins from Eisenia bicyclis","volume":"92","author":"Eom","year":"2012","journal-title":"J. Sci. Food Agric."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1111\/j.1574-6968.2007.00917.x","article-title":"Development of inhibitors against lipase and \u03b1-glucosidase from derivatives of Monascus pigment","volume":"276","author":"Kim","year":"2007","journal-title":"FEMS Microbiol. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1093\/ajcp\/45.4_ts.493","article-title":"Antibiotic susceptibility testing by a standardized single disk method","volume":"45","author":"Bauer","year":"1966","journal-title":"Am. J. Clin. Pathol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Hssaini, L., Razouk, R., and Bouslihim, Y. (2022). Rapid prediction of fig phenolic acids and flavonoids using mid-infrared spectroscopy combined with partial least square regression. Front. Plant Sci., 13.","DOI":"10.3389\/fpls.2022.782159"},{"key":"ref_24","first-page":"767","article-title":"FTIR analysis and quantification of phenols and flavonoids of five commercially available plant extracts used in wound healing","volume":"21","author":"Oliveira","year":"2016","journal-title":"Mat\u00e9ria"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"133430","DOI":"10.1016\/j.foodchem.2022.133430","article-title":"FT-IR and FT-Raman fingerprints of flavonoids\u2014A review","volume":"393","author":"Krysa","year":"2022","journal-title":"Food Chem."},{"key":"ref_26","first-page":"345","article-title":"Study of FTIR spectroscopy combined with chemometrics in the characterization of vegetable tannin from Ceriops decandra","volume":"94","author":"Hossain","year":"2022","journal-title":"Anal. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Ahmed, M., Fatima, H., Qasim, M., Gul, B., and Ihsan-ul, H. (2017). Polarity directed optimization of phytochemical and in vitro biological potential of an indigenous folklore: Quercus dilatata Lindl. ex Royle. BMC Complement. Altern. Med., 17.","DOI":"10.1186\/s12906-017-1894-x"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"326","DOI":"10.3390\/separations10060326","article-title":"Impact and optimization of the extraction conditions of phenolic compounds and antioxidant activity of olive leaves (Moroccan picholine) using response surface methodology","volume":"10","author":"Elhadiri","year":"2023","journal-title":"Separations"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"67","DOI":"10.3390\/molecules19010067","article-title":"Optimized ultrasound-assisted extraction of phenolic compounds from Polygonum cuspidatum","volume":"19","author":"Kuo","year":"2014","journal-title":"Molecules"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhou, L., Jiang, B., Zhang, T., and Li, S. (2019). Ultrasound-assisted aqueous two-phase extraction of resveratrol from the enzymatic hydrolysates of Polygonum cuspidatum. Food Biosci., 31.","DOI":"10.1016\/j.fbio.2019.100442"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Kim, H.D., Choi, H., Abekura, F., Park, J.Y., Yang, W.S., Yang, S.H., and Kim, C.H. (2023). Naturally-occurring tyrosinase inhibitors classified by enzyme kinetics and copper chelation. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24098226"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1186\/s13020-018-0177-x","article-title":"Techniques for extraction and isolation of natural products: A comprehensive review","volume":"13","author":"Zhang","year":"2018","journal-title":"Chin. Med."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/S1004-9541(08)60201-3","article-title":"Solubility of emodin in alcohols","volume":"17","author":"Lin","year":"2009","journal-title":"Chin. J. Chem. Eng."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Ponphaiboon, J., Krongrawa, W., Aung, W.W., Chinatangkul, N., Limmatvapirat, S., and Limmatvapirat, C. (2023). Advances in natural product extraction techniques, electrospun fiber fabrication, and the integration of experimental design: A comprehensive review. Molecules, 28.","DOI":"10.3390\/molecules28135163"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Sultana, T., Ahmed, M., Akhtar, N., Okla, M.K., Al-Hashimi, A., Al-Qahtani, W.H., Abdelgawad, H., and Ihsan-ul, H. (2022). Polarity directed appraisal of pharmacological potential and HPLC-DAD based phytochemical profiling of Polygonum glabrum Willd. Molecules, 27.","DOI":"10.3390\/molecules27020474"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Son, H.U., Yoon, E.K., Yoo, C.Y., Park, C.H., Bae, M.A., Kim, T.H., Lee, C.H., Lee, K.W., Seo, H., and Kim, K.J. (2019). Effects of synergistic inhibition on \u03b1-glucosidase by phytoalexins in soybeans. Biomolecules, 9.","DOI":"10.20944\/preprints201910.0223.v1"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"595393","DOI":"10.1155\/2015\/595393","article-title":"Effect of ethanol\/water solvents on phenolic profiles and antioxidant properties of Beijing propolis extracts","volume":"2015","author":"Sun","year":"2015","journal-title":"Evid.-Based Complement. Altern. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"11119","DOI":"10.3390\/molecules200611119","article-title":"Antibacterial activities and antibacterial mechanism of Polygonum cuspidatum extracts against nosocomial drug-resistant pathogens","volume":"20","author":"Su","year":"2015","journal-title":"Molecules"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"220","DOI":"10.20307\/nps.2016.22.3.220","article-title":"Anti-Helicobacter pylori compounds from Polygonum cuspidatum","volume":"22","author":"Khan","year":"2016","journal-title":"Nat. Prod. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"10668","DOI":"10.1021\/jf1017934","article-title":"Inhibition of pancreatic elastase by polyphenolic compounds","volume":"58","author":"Mateus","year":"2010","journal-title":"J. Agric. Food Chem."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Fletes-Vargas, G., Rodr\u00edguez-Rodr\u00edguez, R., Pacheco, N., P\u00e9rez-Larios, A., and Espinosa-Andrews, H. (2023). Evaluation of the biological properties of an optimized extract of Polygonum cuspidatum using ultrasonic-assisted extraction. Molecules, 28.","DOI":"10.3390\/molecules28104079"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1038\/nrmicro2333","article-title":"How antibiotics kill bacteria: From targets to networks","volume":"8","author":"Kohanski","year":"2010","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_43","first-page":"397","article-title":"Extraction of total phenolic compounds, flavonoids, anthocyanins and tannins from grape by-products by response surface methodology","volume":"5","author":"Rajha","year":"2014","journal-title":"Food Nutr. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1446","DOI":"10.1039\/D3MD00116D","article-title":"Antibacterial activities of anthraquinones: Structure\u2013activity relationships and action mechanisms","volume":"14","author":"Ahmed","year":"2023","journal-title":"RSC Med. Chem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"187","DOI":"10.3839\/jabc.2013.030","article-title":"Antimicrobial effect of emodin isolated from Cassia tora Linn. seeds against food-borne bacteria","volume":"56","author":"Lee","year":"2013","journal-title":"J. Appl. Biol. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2225","DOI":"10.1080\/14786419.2017.1366485","article-title":"Antimicrobial and anti-biofilm activity of tannic acid against Staphylococcus aureus","volume":"32","author":"Dong","year":"2018","journal-title":"Nat. Prod. Res."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Glavnik, V., and Vovk, I. (2020). Extraction of anthraquinones from Japanese knotweed rhizomes and their analyses by high-performance thin-layer chromatography and mass spectrometry. Plants, 9.","DOI":"10.3390\/plants9121753"},{"key":"ref_48","first-page":"132848","article-title":"Recent advances in interactions between polyphenols and plant cell wall polysaccharides as studied using an adsorption technique","volume":"385","author":"Zdunek","year":"2022","journal-title":"Food Chem."}],"container-title":["Antioxidants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3921\/14\/12\/1431\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,30]],"date-time":"2025-11-30T05:13:07Z","timestamp":1764479587000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3921\/14\/12\/1431"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,28]]},"references-count":48,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["antiox14121431"],"URL":"https:\/\/doi.org\/10.3390\/antiox14121431","relation":{},"ISSN":["2076-3921"],"issn-type":[{"value":"2076-3921","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,28]]}}}