6-Bromoindole Derivatives from the Icelandic Marine Sponge Geodia barretti: Isolation and Anti-Inflammatory Activity
AbstractAn UPLC-qTOF-MS-based dereplication study led to the targeted isolation of seven bromoindole alkaloids from the sub-Arctic sponge Geodia barretti. This includes three new metabolites, namely geobarrettin A–C (1–3) and four known compounds, barettin (4), 8,9-dihydrobarettin (5), 6-bromoconicamin (6), and l-6-bromohypaphorine (7). The chemical structures of compounds 1–7 were elucidated by extensive analysis of the NMR and HRESIMS data. The absolute stereochemistry of geobarrettin A (1) was assigned by ECD analysis and Marfey’s method employing the new reagent l-Nα-(1-fluoro-2,4-dinitrophenyl)tryptophanamide (l-FDTA). The isolated compounds were screened for anti-inflammatory activity using human dendritic cells (DCs). Both 2 and 3 reduced DC secretion of IL-12p40, but 3 concomitantly increased IL-10 production. Maturing DCs treated with 2 or 3 before co-culturing with allogeneic CD4+ T cells decreased T cell secretion of IFN-γ, indicating a reduction in Th1 differentiation. Although barettin (4) reduced DC secretion of IL-12p40 and IL-10 (IC50 values 11.8 and 21.0 μM for IL-10 and IL-12p40, respectively), maturing DCs in the presence of 4 did not affect the ability of T cells to secrete IFN-γ or IL-17, but reduced their secretion of IL-10. These results indicate that 2 and 3 may be useful for the treatment of inflammation, mainly of the Th1 type. View Full-Text
- Supplementary File 1:
PDF-Document (PDF, 8183 KB)
Share & Cite This Article
Di, X.; Rouger, C.; Hardardottir, I.; Freysdottir, J.; Molinski, T.F.; Tasdemir, D.; Omarsdottir, S. 6-Bromoindole Derivatives from the Icelandic Marine Sponge Geodia barretti: Isolation and Anti-Inflammatory Activity. Mar. Drugs 2018, 16, 437.
Di X, Rouger C, Hardardottir I, Freysdottir J, Molinski TF, Tasdemir D, Omarsdottir S. 6-Bromoindole Derivatives from the Icelandic Marine Sponge Geodia barretti: Isolation and Anti-Inflammatory Activity. Marine Drugs. 2018; 16(11):437.Chicago/Turabian Style
Di, Xiaxia; Rouger, Caroline; Hardardottir, Ingibjorg; Freysdottir, Jona; Molinski, Tadeusz F.; Tasdemir, Deniz; Omarsdottir, Sesselja. 2018. "6-Bromoindole Derivatives from the Icelandic Marine Sponge Geodia barretti: Isolation and Anti-Inflammatory Activity." Mar. Drugs 16, no. 11: 437.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.