Chromatographic profile of BM-21 and structure of the bioactive flavone glycoside. A) Chemical structure of thalassiolin B (chrysoeriol 7-β-D-glucopyranosyl-2"-sulphate) isolated from T. testudinum. B) HPLC traces of the standard of thalassiolin B. C) HPLC profile of BM-21. The HPLC conditions to obtain B and C were similar (see 'Material and Methods').