title: 2,3-seco-2,3-dioxo-lyngbyatoxin A from a Red Sea strain of the marine cyanobacterium Moorea producens.
abstract: Chemical investigation of the organic extract of a Red Sea strain of the cyanobacterium Moorea producens has afforded 2,3-seco-2,3-dioxo-lyngbyatoxin A (1). Five known compounds including lyngbyatoxin A (2), majusculamides A and B (3 and 4), aplysiatoxin (5) and debromoaplysiatoxin (6) were also isolated. Their structures were elucidated by using HR-FAB-MS, 1D and 2D NMR analyses. The compounds were evaluated for antiproliferative activity against HeLa cancer cells. Lyngbyatoxin A (2) showed potent activity, with an IC50 of 9.2 nM, while 5 and 6 displayed modest activity with IC50 values of 13.3 and 3.03 μM, respectively. In contrast, compounds 1, 3 and 4 were inactive, with IC50 values greater than 50 μM. The lack of cytotoxicity for 2,3-seco-2,3-dioxo-lyngbyatoxin A (1) demonstrates that the indole moiety in lyngbyatoxin (2) is essential for its cytotoxicity, and suggests that detoxification of 2 may be carried out by biological oxidation of the indole moiety to yield 1.
authors.affiliation: a Department of Natural Products , Faculty of Pharmacy, King Abdulaziz University , Jeddah 21589 , Kingdom of Saudi Arabia.
authors.forename: Diaa T A
authors.initials: DT
authors.lastname: Youssef
authors.forename: Lamiaa A
authors.initials: LA
authors.lastname: Shaala
authors.forename: Gamal A
authors.initials: GA
authors.lastname: Mohamed
authors.forename: Sabrin R M
authors.initials: SR
authors.lastname: Ibrahim
authors.forename: Zainy M
authors.initials: ZM
authors.lastname: Banjar
authors.forename: Jihan M
authors.initials: JM
authors.lastname: Badr
authors.forename: Kerry L
authors.initials: KL
authors.lastname: McPhail
authors.forename: April L
authors.initials: AL
authors.lastname: Risinger
authors.forename: Susan L
authors.initials: SL
authors.lastname: Mooberry
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification; D000458:Cyanobacteria / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D019156:Indian Ocean; D020128:Inhibitory Concentration 50; D008235:Lyngbya Toxins / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure
chemical_list: C000598300:2,3-seco-2,3-dioxo-lyngbyatoxin A; D000970:Antineoplastic Agents; D008235:Lyngbya Toxins
keywords: 2,3-seco-2,3-dioxolyngbyatoxin A; HeLa cells; Moorea producens; Red Sea cyanobacterium; antiproliferative activity; lyngbyatoxin