{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,15]],"date-time":"2025-12-15T15:19:18Z","timestamp":1765811958734,"version":"3.48.0"},"reference-count":24,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T00:00:00Z","timestamp":1765584000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Department of Natural Resources of the Guangdong Province","award":["[2024]28"],"award-info":[{"award-number":["[2024]28"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>Four new methionine sulfoxide-containing diketopiperazines, (+)-dysidmetsulfoxide A [(+)-1], (+)-dysidmetsulfoxide B [(+)-2], (+)-dysidmetsulfoxide C [(+)-3] and (\u2212)-dysidmetsulfoxide C [(\u2212)-3], were isolated from the South China Sea sponge Dysidea sp. These compounds represented the first example of diketopiperazines possessing the unit of methionine sulfoxide (MetO) isolated from marine sponges. As it was difficult to determine the configuration of chiral sulfur atom in the thionyl group, the structures with absolute configurations of these compounds were elucidated by spectroscopic analyses and total synthesis. It was noteworthy that the purchased synthetic precursors, Fmoc-L- and Fmoc-D-MetO, were mixtures of epimers, respectively, due to the stereogenic sulfur atom in MetO, which were separated to prepare the optically pure isomers via the method of supercritical fluid chromatography (SFC). In addition, the other four optical isomers [(\u2212)-1, (\u2212)-2, (+)-4 and (\u2212)-4] were also synthesized. Furthermore, (+)-1, (\u2212)-1, (+)-3, (+)-4 and (\u2212)-4 showed potential anti-Parkinson\u2019s disease activities in an in vivo zebrafish model.<\/jats:p>","DOI":"10.3390\/md23120477","type":"journal-article","created":{"date-parts":[[2025,12,15]],"date-time":"2025-12-15T15:15:08Z","timestamp":1765811708000},"page":"477","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Four New Pairs of MetO-Containing Diketopiperazine Enantiomers: Isolation, Synthesis and Potential Anti-Parkinson\u2019s Disease Activity"],"prefix":"10.3390","volume":"23","author":[{"given":"Yu","family":"Lei","sequence":"first","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"},{"name":"Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhenyu","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daichun","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaojian","family":"Liao","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9557-751X","authenticated-orcid":false,"given":"Chamari","family":"Hettiarachchi","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Colombo, Colombo 00700, Sri Lanka"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bingxin","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shihai","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1039\/C8NP00093J","article-title":"Construction of sulfur-containing moieties in the total synthesis of natural products","volume":"37","author":"Wang","year":"2020","journal-title":"Nat. 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