Phloroglucinol

CAS 108-73-6

A classic plant stain hides a selective chemical reaction. Phloroglucinol and hydrochloric acid produce color in many lignified tissues, helping reveal the supporting cell walls of stems and wood. The response targets particular aldehyde-containing structures associated with lignin, so color intensity is not a universal measure of total lignin. Phloroglucinol's three alternating hydroxyl groups also make its aromatic ring electron rich and useful in synthesis. Biology supplies another route: researchers showed that the bacterial enzyme PhlD can build phloroglucinol from malonyl-CoA. The same compact molecule therefore connects microscopy, carbon-carbon bond formation and enzyme chemistry. Its story is about both revealing an existing plant structure and constructing an aromatic structure from smaller metabolic pieces, with different experimental questions guiding each use.