{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,15]],"date-time":"2026-08-15T04:29:49Z","timestamp":1786768189903,"version":"build-2736575974"},"reference-count":48,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Industrial Biocatalysis Hub (IBH) of the Department of Science, Technology and Innovation"},{"id":[{"id":"https:\/\/ror.org\/048kh7197","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Technology and Innovation Agency"},{"DOI":"10.13039\/501100001332","name":"Council for Scientific and Industrial Research","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001332","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05j00sr48","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001333","name":"Rhodes University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001333","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/016sewp10","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Fucoidans are sulphated polysaccharides from brown macroalgae that have attracted considerable interest due to their diverse biological activities and potential applications in metabolic health. In this study, fucoidan-rich extracts were obtained from three South African brown macroalgal species, Ecklonia maxima, Ecklonia radiata, and Sargassum incisifolium, and comparatively characterised using biochemical and physicochemical analyses. The extracts were evaluated for carbohydrate, sulphate, L-fucose, protein, polyphenol, and uronic acid contents, while molecular weight distribution, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and proton Nuclear Magnetic Resonance (1H NMR) spectroscopy were used to investigate structural characteristics. All extracts displayed features characteristic of fucoidans, including sulphated fucose-containing polysaccharides. Notable species-dependent differences were observed, with S. incisifolium exhibiting the highest sulphate (~24%) and polyphenol (~6.76%) contents, stronger sulphate-associated FTIR signals, greater molecular weight heterogeneity, and enhanced thermal stability. The fucoidan-rich extracts exhibited concentration-dependent pancreatic lipase and \u03b1-glucosidase inhibitory activities, together with DPPH radical-scavenging activity. At 1.0 mg\/mL, S. incisifolium demonstrated approximately 66% DPPH radical scavenging and 49% pancreatic lipase inhibition. S. incisifolium and E. radiata exhibited strong \u03b1-glucosidase inhibition, with IC50 values of ~29 and ~46 \u00b5g\/mL, respectively, compared to ~354 \u00b5g\/mL for acarbose. The findings highlight South African brown macroalgae as promising sources of fucoidans and contribute to understanding the relationships among fucoidan composition, structure, and bioactivity.<\/jats:p>","DOI":"10.3390\/molecules31162823","type":"journal-article","created":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T09:31:09Z","timestamp":1786613469000},"page":"2823","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative Characterisation and In Vitro Metabolic Bioactivities of Fucoidan-Rich Extracts from Three South African Brown Macroalgae"],"prefix":"10.3390","volume":"31","author":[{"given":"Coleen E.","family":"Grobler","sequence":"first","affiliation":[{"name":"Enzyme Science Programme (ESP), Department of Biochemistry, Microbiology and Bioinformatics, Rhodes University, Makhanda 6139, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3584-5703","authenticated-orcid":false,"given":"Blessing","family":"Mabate","sequence":"additional","affiliation":[{"name":"Enzyme Science Programme (ESP), Department of Biochemistry, Microbiology and Bioinformatics, Rhodes University, Makhanda 6139, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8940-9552","authenticated-orcid":false,"given":"Justin B.","family":"Safari","sequence":"additional","affiliation":[{"name":"Enzyme Science Programme (ESP), Department of Biochemistry, Microbiology and Bioinformatics, Rhodes University, Makhanda 6139, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8117-1730","authenticated-orcid":false,"given":"Brett I.","family":"Pletschke","sequence":"additional","affiliation":[{"name":"Enzyme Science Programme (ESP), Department of Biochemistry, Microbiology and Bioinformatics, Rhodes University, Makhanda 6139, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Mabate, B., Mkabayi, L., Goddard, D.R., Grobler, C.E., and Pletschke, B.I. (2025). Role of Enzyme Technologies and Applied Enzymology in Valorising Seaweed Bioproducts. Mar. Drugs, 23.","DOI":"10.3390\/md23080303"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Luthuli, S., Wu, S., Cheng, Y., Zheng, X., Wu, M., and Tong, H. (2019). Therapeutic Effects of Fucoidan: A Review on Recent Studies. Mar. Drugs, 17.","DOI":"10.3390\/md17090487"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Jayawardena, T.U., Nagahawatta, D.P., Fernando, I.P.S., Kim, Y.-T., Kim, J.-S., Kim, W.-S., Lee, J.S., and Jeon, Y.-J. (2022). A Review on Fucoidan Structure, Extraction Techniques, and Its Role as an Immunomodulatory Agent. Mar. Drugs, 20.","DOI":"10.3390\/md20120755"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2252659","DOI":"10.1080\/21655979.2023.2252659","article-title":"Advances in oligosaccharides production from brown seaweeds: Extraction, characterization, antimetabolic syndrome, and other potential applications","volume":"14","author":"Perumal","year":"2023","journal-title":"Bioengineered"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Circuncis\u00e3o, A.R., Catarino, M.D., Cardoso, S.M., and Silva, A.M.S. (2018). Minerals from Macroalgae Origin: Health Benefits and Risks for Consumers. Mar. Drugs, 16.","DOI":"10.3390\/md16110400"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"103885","DOI":"10.1016\/j.algal.2024.103885","article-title":"Characterisation of Sargassum elegans fucoidans extracted using different technologies: Linking their structure to \u03b1-glucosidase inhibition","volume":"85","author":"Mabate","year":"2025","journal-title":"Algal Res."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Mabate, B., Daub, C.D., Pletschke, B.I., and Edkins, A.L. (2023). Comparative Analyses of Fucoidans from South African Brown Seaweeds That Inhibit Adhesion, Migration, and Long-Term Survival of Colorectal Cancer Cells. Mar. Drugs, 21.","DOI":"10.3390\/md21040203"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1016\/j.ijbiomac.2020.02.161","article-title":"Fucoidan from Ecklonia maxima is a powerful inhibitor of the diabetes-related enzyme, \u03b1-glucosidase","volume":"151","author":"Daub","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"108784","DOI":"10.1016\/j.foodhyd.2023.108784","article-title":"Marine fucoidans: Structural, extraction, biological activities, and their applications in the food industry","volume":"142","author":"Mensah","year":"2023","journal-title":"Food Hydrocoll."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"537202","DOI":"10.1155\/2013\/537202","article-title":"Analysis by Vibrational Spectroscopy of Seaweed Polysaccharides with Potential Use in Food, Pharmaceutical, and Cosmetic Industries","volume":"2013","author":"Pereira","year":"2013","journal-title":"Int. J. Carbohydr. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"L\u00f3pez-Hortas, L., Fl\u00f3rez-Fern\u00e1ndez, N., Torres, M.D., Ferreira-Anta, T., Casas, M.P., Balboa, E.M., Falqu\u00e9, E., and Dom\u00ednguez, H. (2021). Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics. Mar. Drugs, 19.","DOI":"10.3390\/md19100552"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"122448","DOI":"10.1016\/j.carbpol.2024.122448","article-title":"Structural characterization and immunomodulating assessment of ultra-purified water-extracted fucoidans from Saccharina latissima, Alaria esculenta, and Laminaria hyperborea","volume":"343","author":"Birgersson","year":"2024","journal-title":"Carbohydr. Polym."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Magwaza, S.N., and Islam, M.S. (2023). Roles of Marine Macroalgae or Seaweeds and Their Bioactive Compounds in Combating Overweight, Obesity and Diabetes: A Comprehensive Review. Mar. Drugs, 21.","DOI":"10.3390\/md21040258"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Daub, C.D., Michaels, A.L., Mabate, B., Mkabayi, L., Edkins, A.L., and Pletschke, B.I. (2025). Exploring the Inhibitory Potential of Sodium Alginate against Digestive Enzymes Linked to Obesity and Type 2 Diabetes. Molecules, 30.","DOI":"10.3390\/molecules30051155"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Mabate, B., Daub, C.D., Malgas, S., Edkins, A.L., and Pletschke, B.I. (2021). A Combination Approach in Inhibiting Type 2 Diabetes-Related Enzymes Using Ecklonia radiata Fucoidan and Acarbose. Pharmaceutics, 13.","DOI":"10.3390\/pharmaceutics13111979"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"147","DOI":"10.2989\/1814232X.2012.675125","article-title":"South African kelp moving eastwards: The discovery of Ecklonia maxima (Osbeck) Papenfuss at De Hoop Nature Reserve on the south coast of South Africa","volume":"34","author":"Bolton","year":"2012","journal-title":"Afr. J. Mar. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1007\/s00227-003-1069-9","article-title":"Morphology of Ecklonia radiata (Phaeophyta: Laminarales) along its geographic distribution in south-western Australia and Australasia","volume":"143","author":"Wernberg","year":"2003","journal-title":"Mar. Biol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.sajb.2015.02.008","article-title":"A revision of the genus Sargassum (Fucales, Phaeophyceae) in South Africa","volume":"98","author":"Mattio","year":"2015","journal-title":"S. Afr. J. Bot."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Mmola, M., Roes-Hill, M.L., Durrell, K., Bolton, J.J., Sibuyi, N., Meyer, M.E., Beukes, D.R., and Antunes, E. (2016). Enhanced Antimicrobial and Anticancer Activity of Silver and Gold Nanoparticles Synthesised Using Sargassum incisifolium Aqueous Extracts. Molecules, 21.","DOI":"10.3390\/molecules21121633"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.algal.2016.10.015","article-title":"The seasonal variation of fucoidan within three species of brown macroalgae","volume":"22","author":"Fletcher","year":"2017","journal-title":"Algal Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1007\/s10068-016-0094-7","article-title":"Chemical properties and toxicology studies of fucoidan extracted from Malaysian Sargassum binderi","volume":"25","author":"Lim","year":"2016","journal-title":"Food Sci. Biotechnol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Nguyen, T.T., Mikkelsen, M.D., Tran, V.H.N., Trang, V.T.D., Rhein-Knudsen, N., Holck, J., Rasin, A.B., Cao, H.T.T., Van, T.T.T., and Meyer, A.S. (2020). Enzyme-Assisted Fucoidan Extraction from Brown Macroalgae Fucus distichus subsp. evanescens and Saccharina latissima. Mar. Drugs, 18.","DOI":"10.3390\/md18060296"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"460658","DOI":"10.1016\/j.chroma.2019.460658","article-title":"Size distribution and chain conformation of six different fucoidans using size-exclusion chromatography with multiple detection","volume":"1612","author":"Neupane","year":"2020","journal-title":"J. Chromatogr. A"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2106","DOI":"10.3390\/md9102106","article-title":"Important determinants for fucoidan bioactivity: A critical review of structure\u2013function relations and extraction methods for fucose-containing sulfated polysaccharides from brown seaweeds","volume":"9","author":"Ale","year":"2011","journal-title":"Mar. Drugs"},{"key":"ref_25","unstructured":"Alban, S. (2020). Characterization of the molecular structure of fucoidans using size-exclusion chromatography with multiple detection. Proceedings of The ABC Conference: Algae Bioactive Compounds\u2014From Research to Innovation, Kiel, Germany (online), 25\u201326 August 2020, Medical Science GMS Publishing House. Doc20fucosan05 German."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1016\/j.carbpol.2018.02.035","article-title":"Size-dependent pharmacological activities of differently degraded fucoidan fractions from Fucus vesiculosus","volume":"189","author":"Lahrsen","year":"2018","journal-title":"Carbohydr. Polym."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e5","DOI":"10.1017\/jns.2020.56","article-title":"Comparison of edible brown algae extracts for the inhibition of intestinal carbohydrate digestive enzymes involved in glucose release from the diet","volume":"10","author":"Attjioui","year":"2021","journal-title":"J. Nutr. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1671","DOI":"10.3390\/molecules13081671","article-title":"Fucoidan: Structure and bioactivity","volume":"13","author":"Li","year":"2008","journal-title":"Molecules"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"530","DOI":"10.1016\/j.carbpol.2007.01.009","article-title":"Characterization of polysaccharides extracted from brown seaweeds","volume":"69","author":"Rioux","year":"2007","journal-title":"Carbohydr. Polym."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Soto-Varela, R., Alvarado-Garc\u00eda, A., Youssef, F.S., Ashour, M.L., Bogari, H.A., and Elhady, S.S. (2023). FTIR characterization of sulfated polysaccharides obtained from Macrocystis integrifolia algae and verification of their antiangiogenic and immunomodulatory potency in vitro and in vivo. Mar. Drugs, 21.","DOI":"10.3390\/md21010036"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"911","DOI":"10.1016\/j.foodchem.2017.11.083","article-title":"Bioactivity of fucoidan extracted from Laminaria japonica using a novel procedure with high yield","volume":"245","author":"Zhao","year":"2018","journal-title":"Food Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"8131","DOI":"10.1039\/C3RA23373A","article-title":"Fucoidans from brown seaweeds: An update on structures, extraction techniques and use of enzymes as tools for structural elucidation","volume":"3","author":"Ale","year":"2013","journal-title":"RSC Adv."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2769","DOI":"10.1016\/j.carres.2011.09.034","article-title":"Sulfated polysaccharides from brown seaweeds Saccharina japonica and Undaria pinnatifida: Isolation, structural characteristics, and antitumor activity","volume":"346","author":"Vishchuk","year":"2011","journal-title":"Carbohydr. Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"32447","DOI":"10.1021\/acsomega.0c04591","article-title":"Structure and Biological Activity Analysis of Fucoidan Isolated from Sargassum siliquosum","volume":"5","author":"Wang","year":"2020","journal-title":"ACS Omega"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jaap.2011.01.004","article-title":"Biomass pyrolysis kinetics: A comparative critical review with relevant agricultural residue case studies","volume":"91","author":"White","year":"2011","journal-title":"J. Anal. Appl. Pyrolysis"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1016\/j.biortech.2015.05.062","article-title":"Characteristics and kinetic study on pyrolysis of five lignocellulosic biomass via thermogravimetric analysis","volume":"192","author":"Chen","year":"2015","journal-title":"Bioresour. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"101399","DOI":"10.1016\/j.algal.2018.101399","article-title":"Characterization and thermal decomposition of demineralized wastewater algae biomass","volume":"38","author":"Carpio","year":"2019","journal-title":"Algal Res."},{"key":"ref_38","unstructured":"Pirahanchi, Y., and Sharma, S. (2026, June 03). Biochemistry, Lipase, StatPearls [Internet], Available online: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK537346\/."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4157","DOI":"10.1002\/jsfa.13297","article-title":"Effect of in vitro simulated digestion on the physicochemical properties and pancreatic lipase inhibitory activity of fucoidan","volume":"104","author":"Lu","year":"2024","journal-title":"J. Sci. Food Agric."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"8649365","DOI":"10.1155\/2024\/8649365","article-title":"Laminaria japonica Aresch-Derived Fucoidan Ameliorates Hyperlipidemia by Upregulating LXRs and Suppressing SREBPs","volume":"2024","author":"Zhang","year":"2024","journal-title":"Cardiovasc. Ther."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Koh, H.S.A., Lu, J., and Zhou, W. (2020). Structural Dependence of Sulfated Polysaccharide for Diabetes Management: Fucoidan from Undaria pinnatifida Inhibiting \u03b1-Glucosidase More Strongly Than \u03b1-Amylase and Amyloglucosidase. Front. Pharmacol., 11.","DOI":"10.3389\/fphar.2020.00831"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3689724","DOI":"10.1155\/2022\/3689724","article-title":"Characteristics and Antioxidant Activity of Fucoidan from Sargassum hystrix: Effect of Extraction Method","volume":"2022","author":"Husni","year":"2022","journal-title":"Int. J. Food Sci."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Pozharitskaya, O.N., Obluchinskaya, E.D., and Shikov, A.N. (2020). Mechanisms of Bioactivities of Fucoidan from the Brown Seaweed Fucus vesiculosus L. of the Barents Sea. Mar. Drugs, 18.","DOI":"10.3390\/md18050275"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1021\/ac60111a017","article-title":"Colorimetric method for determination of sugars and related substances","volume":"28","author":"Dubois","year":"1956","journal-title":"Anal. Chem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/S0021-9258(18)57178-7","article-title":"A specific color reaction of methylpentoses and a spectrophotometric micromethod for their determination","volume":"175","author":"Dische","year":"1948","journal-title":"J. Biol. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1042\/bj0840106","article-title":"A note on the determination of the ester sulphate content of sulphated polysaccharides","volume":"84","author":"Dodgson","year":"1962","journal-title":"Biochem. J."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/0003-2697(76)90527-3","article-title":"A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding","volume":"72","author":"Bradford","year":"1976","journal-title":"Anal. Biochem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1841","DOI":"10.1021\/jf030723c","article-title":"The Chemistry behind Antioxidant Capacity Assays","volume":"53","author":"Huang","year":"2005","journal-title":"J. Agric. Food Chem."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/16\/2823\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,15]],"date-time":"2026-08-15T04:24:59Z","timestamp":1786767899000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/16\/2823"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,13]]},"references-count":48,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["molecules31162823"],"URL":"https:\/\/doi.org\/10.3390\/molecules31162823","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,13]]}}}