{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:53:39Z","timestamp":1785891219306,"version":"3.56.0"},"reference-count":31,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2013,8,22]],"date-time":"2013-08-22T00:00:00Z","timestamp":1377129600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>Two new diterpenoids, pachydictyol B (1a\/1b) and C (2), were isolated from the dichloromethane extract of the marine brown alga, Dictyota dichotoma, collected from  the Red Sea coast of Egypt, along with the known metabolites, pachydictyol A (3a),  dictyol E (4), cis-africanan-1\u03b1-ol (5a), fucosterol (6), tetrahydrothiophen-1,1-dioxide and poly-\u03b2-hydroxybutyric acid. GC-MS analysis of the nonpolar fractions also indicated the presence of \u03b2-bourbonene and nonanal, along with three hydrocarbons and five fatty acids or their simple derivatives, respectively. GC-MS analysis of the unsaponifiable algal petroleum ether extract revealed the presence of a further eight compounds, among them 2,2,6,7-tetramethyl-10-oxatricyclo[4.3.0.1(1,7)]decan-5-one (7), N-(4-bromo-n-butyl)-pipe ridin-2-one (8) and tert-hexadecanethiol. Structures 1\u20136 were assigned by 1D and 2D NMR, mass spectra (EI, CI, HREI and HRESI) and by comparison with data from related structures. The crude algal extract was potently active against the breast carcinoma tumor cell line, MCF7 (IC50 = 0.6 \u00b5g mL\u22121); pachydictyol B (1a) and dictyol E (4) showed weak antimicrobial properties, and the other compounds were inactive. Pachydictyols B (1a) and C (2) demonstrated a weak and unselective cytotoxicity against twelve human tumor cell lines with a mean IC50 of &gt;30.0 \u00b5M.<\/jats:p>","DOI":"10.3390\/md11093109","type":"journal-article","created":{"date-parts":[[2013,8,22]],"date-time":"2013-08-22T11:56:40Z","timestamp":1377172600000},"page":"3109-3123","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Pachydictyols B and C: New Diterpenes from  Dictyota dichotoma Hudson"],"prefix":"10.3390","volume":"11","author":[{"given":"Ghada","family":"Abou-El-Wafa","sequence":"first","affiliation":[{"name":"Department of Botany, Faculty of Science, Mansoura University, Algomhuria St. 60,  El-Mansoura 35516, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"Shaaban","sequence":"additional","affiliation":[{"name":"Institute of Organic and Biomolecular Chemistry, University of G\u00f6ttingen, Tammannstrasse 2,  D-37077 G\u00f6ttingen, Germany"},{"name":"Chemistry of Natural Compounds Department, Division of Pharmaceutical Industries, National Research Centre, El-Behoos St. 33, Dokki-Cairo 12622, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Khaled","family":"Shaaban","sequence":"additional","affiliation":[{"name":"Institute of Organic and Biomolecular Chemistry, University of G\u00f6ttingen, Tammannstrasse 2,  D-37077 G\u00f6ttingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"El-Naggar","sequence":"additional","affiliation":[{"name":"Department of Botany, Faculty of Science, Mansoura University, Algomhuria St. 60,  El-Mansoura 35516, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Armin","family":"Maier","sequence":"additional","affiliation":[{"name":"Oncotest GmbH, Am Flughafen 12-14, D-79108 Freiburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heinz","family":"Fiebig","sequence":"additional","affiliation":[{"name":"Oncotest GmbH, Am Flughafen 12-14, D-79108 Freiburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hartmut","family":"Laatsch","sequence":"additional","affiliation":[{"name":"Institute of Organic and Biomolecular Chemistry, University of G\u00f6ttingen, Tammannstrasse 2,  D-37077 G\u00f6ttingen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2013,8,22]]},"reference":[{"key":"ref_1","unstructured":"Vashishta, B.R. 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