allantoin

Allantoin
IUPAC name	(2,5-Dioxo-4-imidazolidinyl) urea
Other names	• Alcloxa • Aldioxa • Ureidohydantoin •Glyoxyldiureide •Hemocane • 5-Ureidohydantoin • Vitamin U (formerly)[1]
Identifiers
CAS number	97-59-6 Y
SMILES	O=C1C(NC(=O)N1)NC(=O)N
Properties
Molecular formula	C4H6N4O3
Molar mass	158.12 g mol−1
Appearance	colourless crystalline powder
Density	1.45g/cm3
Melting point	230 °C, 503 K, 446 °F
Solubility in water	0.5% at 25 °C
Hazards
MSDS	Allantoin MSDS (PDF)
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Allantoin is a chemical compound with formula C₄H₆N₄O₃. It is also called 5-ureidohydantoin or glyoxyldiureide. It is a diureide of glyoxylic acid. Named after the allantois, an amniote embryonic excretory organ in which it concentrates during development in most mammals except humans and higher apes, it is a product of oxidation of uric acid by purine catabolism. After birth, it is the predominant means by which nitrogenous waste is excreted in the urine of these animals.^[2] In humans and higher apes, the metabolic pathway for conversion of uric acid to allantoin is not present, so the former is excreted. Recombinant rasburicase is sometimes used as a drug to catalyze this metabolic conversion in patients. In fish, allantoin is broken down further (into ammonia) before excretion.^[3] Allantoin is a major metabolic intermediate in many other organisms including plants and bacteria.

Applications

Allantoin is present in botanical extracts of the comfrey plant and urine from cows and most mammals. Chemically synthesized bulk allantoin is nature-identical, safe, non-toxic, compatible with cosmetic raw materials and meets CTFA and JSCI requirements.^[4] Over 10,000 patents reference allantoin. ^[5] Manufacturers cite several beneficial effects for allantoin as an active ingredient in over-the-counter cosmetics: a moisturizing and keratolytic effect, increasing the water content of the extracellular matrix and enhancing the desquamation of upper layers of dead skin cells, increasing the smoothness of the skin; promotion of cell proliferation and wound healing; and a soothing, anti-irritant, and skin protectant effect by forming complexes with irritant and sensitizing agents.^[6] It is frequently present in toothpaste, mouthwash, and other oral hygiene products, in shampoos, lipsticks, anti-acne products, sun care products, and clarifying lotions, various cosmetic lotions and creams, and other cosmetic and pharmaceutical products. Allantoin has not been proven scientifically to reduce the appearance of aging.^[7]

See also

• Imidazolidinyl urea and diazolidinyl urea, antimicrobial condensation products of allantoin with formaldehyde

References