New cycloartanol sulfates from the alga Tydemania expeditionis: inhibitors of the protein tyrosine kinase pp60v-src.

Bioactivity-directed fractionation of the extracts of the green alga Tydemania expeditionis using the protein tyrosine kinase pp60v-src led to the isolation of three new cycloartanol disulfates, 1-3, which show modest inhibition of this enzyme. The structures were deduced by spectroscopic methods.