What has a structure resembling diferulic acid and is bright yellow?
Curcumin Curcumin is a bright yellow chemical produced by some plants. It is the principal curcuminoid of turmeric ("Curcuma longa"), a member of the ginger family (Zingiberaceae). It is sold as an herbal supplement, cosmetics ingredient, food flavoring, and food coloring. As a food additive, its E number is E100.
Acid-fastness Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Once stained as part of a sample, these organisms can resist the acid and/or ethanol-based decolorization procedures common in many staining protocols, hence the name "acid-fast".