A Madagascar Sponge Batzella sp. as a source of alkylated iminosugars

Three new C-alkylated iminosugars, batzellasides A (3), B (4), and C (5), along with the known halitoxin (2) polymer were isolated from a Batzella sp. sponge, collected off the west coast of Madagascar. Although this class of azasugars is well known from terrestrial sources, our report represents the first examples of iminosugars from a marine organism. Comparison with the properties of known natural and synthetic iminosugars assisted in the structure determinations. Compounds 3-5 inhibited the growth of Staphylococcus epidermidis with MICs of < or =6.3 microg/mL.