4 NEW BIOACTIVE POLYBROMINATED DIPHENYL ETHERS OF THE SPONGE DYSIDEA-HERBACEA FROM WEST SUMATRA, INDONESIA

The marine sponge Dysidea herbacea collected from Indonesia yielded fo ur new polybrominated diphenyl ether congeners 2-5 and the known deriv atives 1, 6, and 7. The structures of the new compounds were unambiguo usly established on the basis of NMR spectroscopic (H-1, C-13, COSY, H -1-detected direct and long-range C-13-H-1 correlations) and mass spec trometric (EIMS) data. All of the compounds were active against the Gr am-positive bacteria Bacillus subtilis and the phytopathogenic fungus Cladosporium cucumerinum. The isolated polybrominated compounds were a lso active in the brine shrimp lethality test. In the latter bioassay, compounds 1 and 6 were the most active with LC50's of 0.96 [SE +/- 0. 19] and 0.94 [SE +/- 0.70] mu g/mL, respectively.