Figure 2.
Bioassay-guided fractionation and identification of an active compound. (A) Using fluorescent puncta in yeast expressing Q103-GFP as a guide, the active HPLC fractions in crude extracts of SID#13569 were determined. Representative images are shown, and the arrows indicate puncta. Scale bar is 2 μm. The results were quantified by counting more than 200 yeast from random fields and scoring individual cells for the presence of well-resolved puncta. (B) The chemical structure of actinomycin D.