Secondary Metabolites with Anti-Inflammatory Activity from <i>Laurencia majuscula</i> Collected in the Red Sea
Mohamed A. Tammam,
Maria G. Daskalaki,
Nikolaos Tsoureas,
Ourania Kolliniati,
Aldoushy Mahdy,
Sotirios C. Kampranis,
Christos Tsatsanis,
Vassilios Roussis,
Efstathia Ioannou
Affiliations
Mohamed A. Tammam
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, Medical School, University of Crete, 70013 Heraklion, Greece
Nikolaos Tsoureas
Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15784 Athens, Greece
Ourania Kolliniati
Laboratory of Clinical Chemistry, Medical School, University of Crete, 70013 Heraklion, Greece
Aldoushy Mahdy
Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut 71524, Egypt
Sotirios C. Kampranis
Section of Plant Biochemistry, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
Christos Tsatsanis
Laboratory of Clinical Chemistry, Medical School, University of Crete, 70013 Heraklion, Greece
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
The chemical investigation of the organic extract of the red alga Laurencia majuscula collected from Hurghada reef in the Red Sea resulted in the isolation of five C15 acetogenins, including four tricyclic ones of the maneonene type (1–4) and a 5-membered one (5), 15 sesquiterpenes, including seven lauranes (6–12), one cuparane (13), one seco-laurane (14), one snyderane (15), two chamigranes (16, 17), two rearranged chamigranes (18, 19) and one aristolane (20), as well as a tricyclic diterpene (21) and a chlorinated fatty acid derivative (22). Among them, compounds 1–3, 5, 7, 8, 10, 11 and 14 are new natural products. The structures and the relative configurations of the isolated natural products have been established based on extensive analysis of their NMR and MS data, while the absolute configuration of maneonenes F (1) and G (2) was determined on the basis of single-crystal X-ray diffraction analysis. The anti-inflammatory activity of compounds 1, 2, 4–8, 10, 12–16, 18 and 20–22 was evaluated by measuring suppression of nitric oxide (NO) release in TLR4-activated RAW 264.7 macrophages in culture. All compounds, except 6, exhibited significant anti-inflammatory activity. Among them, metabolites 1, 4 and 18 did not exhibit any cytostatic activity at the tested concentrations. The most prominent anti-inflammatory activity, accompanied by absence of cytostatic activity at the same concentration, was exerted by compounds 5 and 18, with IC50 values of 3.69 μM and 3.55 μΜ, respectively.
