lissoclin Disulfoxide, A Novel Dimeric Alkaloid from the AscidianlissoclinumSp.: Inhibitor of Interleukin-8 Receptors

Bioassay-guided fractionation of the MeOH extract of the South African ascidian Lissoclinum sp. yielded three known compounds plus a novel alkaloid, lissoclin disulfoxide (1), whose structure was determined by interpretation of spectral data. Alkaloid 1 had IC50 values of 0.6 and 0.82 μM against the inhibition of IL-8 Rα and IL-8 Rβ receptors, respectively.