Polyhydroxy)benzenes

Abstract

This article describes the tri‐, tetra‐, penta‐, and hexahydroxybenzenes. The tetra‐, penta‐, and hexahydroxybenzenes are also referred to as benzenetetrols, benzenepentol, and benzenehexol, respectively, and the trihydroxybenzenes are more familiarly known by their trivial names, ie, pyrogallol (or pyrogallic acid), hydroxyhydroquinone, and phloroglucinol, for the 1,2,3‐, 1,2,4‐, and 1,3,5‐isomers, respectively. Included are their syntheses, manufacture where applicable, and occurrence. Physical properties, analyses, chemical properties, uses, and toxicity data are described. The chemistry of the (polyhydroxy)benzenes is presented as is that of their derivatives. Related compounds having the basic structure of the various (polyhydroxy)benzenes are also described. Included are their occurrence and chemical and physiological properties. Most of the physiological activities and uses of the (polyhydroxy)benzenes are attributable to their oxidation–reduction potentials; these compounds are strong reducing agents, useful in photographic developers, photosensitive compositions, hair dyes, and chemical analyses. The benzenepolyols and their derivatives have found use in virtually all phases of chemistry: synthesis, antioxidants, heat and light stabilizers, pesticides, in polymers, resins, and adhesives, pharmaceuticals, cosmetics, and food additives, etc.

Pyrogallol-associated dermal toxicity and carcinogenicity in F344/N rats and B6C3F1/N mice

“…Pyrogallol is a benzenetriol produced when carbon dioxide is split from gallic acid by heat [1]; it can be found in nature as a product of the decomposition of plant tannins and is produced commercially from gallic acid [2, 3]. Historically, pyrogallol has been used as a hair dye, leather and wool stain and photographic developer.…”

“…Historically, pyrogallol has been used as a hair dye, leather and wool stain and photographic developer. However, current main commercial applications in the United States include corrosion-inhibition (to protect metals during processing or cleaning) and the manufacture of other chemicals [2]. During the late 1980s and early 1990s, hair dyes sold in the United States contained 0.1% to 5.0% pyrogallol by weight [4, 5], however, pyrogallol-based hair dyes are not currently available to the public (R.L.…”