Halichoblelide, a potent cytotoxic macrolide from a Streptomyces species separated from a marine fish

Halichoblelide, a novel macrolide with potent cytotoxicity against tumour cells in culture, has been isolated from a strain of Streptomyces hygroscopicus originally separated from the marine fish Halichoeres bleekeri, and the absolute stereostructure has been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformations.