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

Abstract

Three new polysulfur alkaloids, lissoclibadins 1 ( 1 )–3 ( 3 ), were isolated from the ascidian Lissoclinum sp. (cf. L. badium Monniot, F. and Monniot, C., 1996). The structures of 1– 3 were assigned on the basis of their spectral data, and the computational modeling study was utilized for 1 . Compound 1 had a trimeric structure of three identical aromatic anime moieties connected through two sulfide and a disulfide bonds. Compounds 2 and 3 were dimeric structures of the same unit as that of 1 connected through a sulfide and disulfide bonds ( 2 ) and two sulfide bonds ( 3 ). Compounds 1 and 2 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 2 showed antifungal activity to Mucor hiemalis (13.8 mm at 50 μg/disk). Compounds 1– 3 were cytotoxic against HL-60 (IC 50=0.37, 0.21, and 5.5 μM, respectively).