Perthamides C-F, potent human antipsoriatic cyclopeptides
Abstract Two new cyclopeptides, perthamides E and F were isolated from the polar extracts of the sponge Theonella swinhoei . The new structures, featuring an unprecedented β-amino acid unit (AHMOA), were determined by interpretation of NMR and MS data. The absolute configuration of the AHMOA residue was proposed on the basis of quantum chemical calculation of NMR chemical shifts. Perthamides were proved to inhibit TNF-α and IL-8 release in primary human keratinocytes cells and therefore could represent potentially leads for the treatment of psoriasis.
Coscinolactams A and B: new nitrogen-containing sesterterpenoids from the marine sponge Coscinoderma mathewsi exerting anti-inflammatory properties
Abstract Investigation of the marine sponge Coscinoderma mathewsi led to the isolation of two novel nitrogen-containing cheilanthane sesterterpenoids, coscinolactams A and B, together with known suvanine. The structures were elucidated by extensive spectroscopic measurements including NOE experiments to deduce the stereochemistry. The natural compounds, as well as a semisynthetic derivative, showed moderate anti-inflammatory activity measured as their capability to inhibit PGE2 and NO production. The suvanine aldehyde derivative 4 inhibited inducible nitric oxide protein expression with an IC50 value of 7.3 μM.