Solomonamides A and B, new anti-inflammatory peptides from Theonella swinhoei

Two unprecedented cyclic peptides, solomonamides A and B, were isolated from the marine sponge Theonella swinhoei. The structures were elucidated on the basis of comprehensive 1D and 2D NMR analysis and high-resolution mass spectrometry. A combined approach, involving Marfey's method, QM J based analysis, and DFT J/(13)C calculations, was used for establishing the absolute configuration of the entire molecule. Solomonamide A showed in vivo anti-inflammatory activity.