{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T21:32:51Z","timestamp":1779917571734,"version":"3.53.1"},"reference-count":28,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,10,29]],"date-time":"2022-10-29T00:00:00Z","timestamp":1667001600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation of Korea","award":["NRF-2020R1I1A1A01061094"],"award-info":[{"award-number":["NRF-2020R1I1A1A01061094"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>Dieckol, a phlorotannin from Ecklonia cava, has shown potential for use as an anticancer agent that selectively kills cancer cells. However, it is necessary to amplify its potency without damaging its inherent safety in order to develop it as a competitive chemotherapeutic. Here, we explored the controlled O-acylations of dieckol. Acyl groups could be consistently introduced to the 6-O position of dieckol with a high regioselectivity, which was confirmed by NOESY, HMBC and HSQC spectroscopies. In cytotoxicity studies on the newly synthesized 6-O-acetyl, 6-O-benzoyl dieckols and previously synthesized 6-O-alkyl dieckols against A549 vs. normal cells, all of the derivatives showed low cytotoxicity in normal cells with an IC50 of 481\u2013719 \u03bcM, and highly structure-dependent cytotoxicity in A549 cells with an IC50 of 7.02 (acetyl)\u2212842.26 (benzyl) \u03bcM. The selectivity index also showed a large structure dependency in the range of 0.67 (benzyl)\u201368.58 (acetyl). An analysis of the structure\u2013activity relationship indicated that the activity was dramatically reduced in the presence of a benzene ring and was highly increased in the presence of small polar substituents. Conclusions: Controlled mono-O-modifications of dieckol could be a powerful tool to enhance the anticancer activity of dieckol, thus contributing to the development strategy for dieckol-based chemotherapeutics.<\/jats:p>","DOI":"10.3390\/md20110683","type":"journal-article","created":{"date-parts":[[2022,10,30]],"date-time":"2022-10-30T07:26:50Z","timestamp":1667114810000},"page":"683","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Regioselective Synthesis of 6-O-Acetyl Dieckol and Its Selective Cytotoxicity against Non-Small-Cell Lung Cancer Cells"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6785-7111","authenticated-orcid":false,"given":"Hyeon-Cheol","family":"Shin","sequence":"first","affiliation":[{"name":"Center for Molecular Intelligence, The State University of New York, Korea, 119 Songdomunhwa-ro, Yeonsu-gu, Incheon 21985, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongkyun","family":"Kim","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering and Material Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 03722, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jaeyeong","family":"Choi","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering and Material Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 03722, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hyun Bae","family":"Kang","sequence":"additional","affiliation":[{"name":"Healinnols Inc., 1662 Yuseong-daero, Yuseong-gu, Daejeon 34054, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7055-6341","authenticated-orcid":false,"given":"Seung-Yun","family":"Han","sequence":"additional","affiliation":[{"name":"College of Medicine, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kwangyong","family":"Park","sequence":"additional","affiliation":[{"name":"School of Chemical Engineering and Material Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 03722, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9236-536X","authenticated-orcid":false,"given":"Hye Jeong","family":"Hwang","sequence":"additional","affiliation":[{"name":"Center for Molecular Intelligence, The State University of New York, Korea, 119 Songdomunhwa-ro, Yeonsu-gu, Incheon 21985, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Basak, D., Arrighi, S., Darwiche, Y., and Deb, S. 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