Thuwalallenes A–E and Thuwalenynes A–C: New C<sub>15</sub> Acetogenins with Anti-Inflammatory Activity from a Saudi Arabian Red Sea <i>Laurencia</i> sp.
Aikaterini Koutsaviti,
Maria G. Daskalaki,
Susana Agusti,
Sotirios C. Kampranis,
Christos Tsatsanis,
Carlos M. Duarte,
Vassilios Roussis,
Efstathia Ioannou
Affiliations
Aikaterini Koutsaviti
Section of Pharmacognosy and Chemistry of Natural Products, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
Maria G. Daskalaki
Laboratory of Clinical Chemistry, School of Medicine, University of Crete, 70013 Heraklion, Greece
Susana Agusti
Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
Sotirios C. Kampranis
Laboratory of Clinical Chemistry, School of Medicine, University of Crete, 70013 Heraklion, Greece
Christos Tsatsanis
Laboratory of Clinical Chemistry, School of Medicine, University of Crete, 70013 Heraklion, Greece
Carlos M. Duarte
Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
Vassilios Roussis
Section of Pharmacognosy and Chemistry of Natural Products, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
Efstathia Ioannou
Section of Pharmacognosy and Chemistry of Natural Products, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
Thuwalallenes A−E (1−3, 5 and 8) and thuwalenynes A−C (4, 6, 7), new C15 acetogenins featuring uncommon ring systems, along with cis-maneonene D (9), thyrsiferol (10) and 23-acetyl-thyrsiferol (11) were isolated from the organic extract of a population of the red alga Laurencia sp., collected at Rose Reef off the village of Thuwal in the Red Sea waters of the Kingdom of Saudi Arabia. The structure elucidation of the isolated natural products was based on extensive analysis of their spectroscopic data. Compounds 1−6, 8, 10 and 11 were evaluated for their anti-inflammatory activity by quantifying nitric oxide (NO) release in response to TLR4 stimulation in macrophages. Besides compound 4 that did not exhibit any activity, all other tested metabolites inhibited NO production from activated macrophages. Among them, thyrsiferol (10) and 23-acetylthyrsiferol (11) displayed activity with IC50 values in the low nM scale without cytotoxicity.
