Lissoclibadins 1–3, three new polysulfur alkaloids, from the ascidian Lissoclinum cf. Badium

Three new polysulfur alkaloids, lissoclibadins 1 ()–3 (), were isolated from the ascidian Lissoclinum sp. (cf. L. badium Monniot, F. and Monniot, C., 1996). The structures of were assigned on the basis of their spectral data, and the computational modeling study was utilized for . Compound had a trimeric structure of three identical aromatic anime moieties connected through two sulfide and a disulfide bonds. Compounds and were dimeric structures of the same unit as that of connected through a sulfide and disulfide bonds () and two sulfide bonds (). Compounds and inhibited the growth of the marine bacterium Ruegeria atlantica (15.2 mm at 20 μg/disk and 12.2 mm at 5 μg/disk, respectively) and showed antifungal activity to Mucor hiemalis (13.8 mm at 50 μg/disk). Compounds were cytotoxic against HL-60 (IC50=0.37, 0.21, and 5.5 μM, respectively).