Dragmacidin F: A new antiviral bromoindole alkaloid from the mediterraneansponge Halicortex sp.

A new bromoindole alkaloid, named dragmacidin F (1) and structurally relate d to other dragmacidins previously described, was isolated from a marine sp onge of the genus Halicortex collected off the southern coast of Ustica Isl and (Italy). Structural elucidation of 1 was achieved by an extensive spect roscopic study (mainly by 1D/2D-NMR and MS techniques). Compound 1, contain ing an unprecedented carbon skeleton that is very likely derived from cycli zation of a partially oxidized form of dragmacidin D (2), showed in vitro a ntiviral activity against HSV-1 (EC50=95.8 mu M) and HIV-1 (EC50=0.91 mu M) , thus proving to be responsible for the antiviral property exhibited by Ha licortex extracts. (C) 2000 Elsevier Science Ltd. All rights reserved.