{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T12:48:03Z","timestamp":1785415683767,"version":"3.56.0"},"reference-count":36,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,20]],"date-time":"2020-05-20T00:00:00Z","timestamp":1589932800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013209","name":"Hellenic Foundation for Research and Innovation","doi-asserted-by":"publisher","award":["16228"],"award-info":[{"award-number":["16228"]}],"id":[{"id":"10.13039\/501100013209","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100013209","name":"Hellenic Foundation for Research and Innovation","doi-asserted-by":"publisher","award":["1090"],"award-info":[{"award-number":["1090"]}],"id":[{"id":"10.13039\/501100013209","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Diterpenes are characteristic compounds from the genus Sideritis L., possessing an array of biological activities. Siderol is the main constituent of the ent-kaurene diterpenes in Sideritis species. In order to isolate the specific compound and evaluate for the first time its cytotoxic activity, we explored the dichloromethane extract of cultivated Sideritis euboea Heldr. To track the specific natural bioactive agent, we applied NMR spectroscopy to the crude plant extract, since NMR can serve as a powerful and rapid tool both to navigate the targeted isolation process of bioactive constituents, and to also reveal the identity of bioactive components. Along these lines, from the rapid 1D 1H NMR spectrum of the total crude plant extract, we were able to determine the characteristic proton NMR signals of siderol. Furthermore, with the same NMR spectrum, we were able to categorize several secondary metabolites into chemical groups as a control of the isolation process. Therefore, this non-polar extract was explored, for the first time, revealing eleven compounds\u2014one fatty acid ester; 2-(p-hydroxyphenyl)ethylstearate (1), three phytosterols; \u03b2-sitosterol (2), stigmasterol (3), and campesterol (4); one triterpenoid; ursolic acid (5), four diterpenoids; siderol (6), eubol (7), eubotriol (8), 7-epicandicandiol (9) and two flavonoids; xanthomicrol (10) and penduletin (11). The main isolated constituent was siderol. The antiproliferative potential of siderol was evaluated, using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay, on three human cancer cell lines DLD1, HeLa, and A549, where the IC50 values were estimated at 26.4 \u00b1 3.7, 44.7 \u00b1 7.2, and 46.0 \u00b1 4.9 \u03bc\u039c, respectively. The most potent activity was recorded in the human colon cancer cell line DLD1, where siderol exhibited the lowest IC50. Our study unveiled the beneficial potential of siderol as a remarkable cytotoxic agent and the significant contribution of NMR spectroscopy towards the isolation and identification of this potent anticancer agent.<\/jats:p>","DOI":"10.3390\/molecules25102382","type":"journal-article","created":{"date-parts":[[2020,5,22]],"date-time":"2020-05-22T10:18:18Z","timestamp":1590142698000},"page":"2382","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["NMR-Based Chemical Profiling, Isolation and Evaluation of the Cytotoxic Potential of the Diterpenoid Siderol from Cultivated Sideritis euboea Heldr."],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4313-9657","authenticated-orcid":false,"given":"Ekaterina-Michaela","family":"Tomou","sequence":"first","affiliation":[{"name":"Department of Pharmacognosy &amp; Chemistry of Natural Products, School of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria V.","family":"Chatziathanasiadou","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paschalina","family":"Chatzopoulou","sequence":"additional","affiliation":[{"name":"Hellenic Agricultural Organization DEMETER, Institute of Breeding and Plant Genetic Resources, IBPGR, Department of Medicinal and Aromatic Plants, Thermi, 57001 Thessaloniki, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6391-0288","authenticated-orcid":false,"given":"Andreas G.","family":"Tzakos","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helen","family":"Skaltsa","sequence":"additional","affiliation":[{"name":"Department of Pharmacognosy &amp; Chemistry of Natural Products, School of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1007\/s40199-019-00261-8","article-title":"Genus Sideritis, section Empedoclia in southeastern Europe and Turkey\u2013studies in ethnopharmacology and recent progress of biological activities","volume":"27","author":"Aneva","year":"2019","journal-title":"DARU J. 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