出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2016/05/22 05:03:08」(JST)
Names | |
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IUPAC name
(2,5-Dioxo-4-imidazolidinyl) urea
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Other names
Glyoxyldiureide
5-Ureidohydantoin |
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Identifiers | |
CAS Number
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97-59-6 Y |
ChEBI | CHEBI:15676 Y |
ChEMBL | ChEMBL593429 Y |
ChemSpider | 199 Y |
EC Number | 202-592-8 |
Jmol 3D model | Interactive image Interactive image |
KEGG | D00121 Y |
PubChem | 204 |
RTECS number | YT1600000 |
UNII | 344S277G0Z Y |
InChI
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SMILES
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Properties | |
Chemical formula
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C4H6N4O3 |
Molar mass | 158.12 g·mol−1 |
Appearance | colourless crystalline powder |
Odor | odorless |
Density | 1.45 g/cm3 |
Melting point | 230 °C (446 °F; 503 K) (decomposes) |
Boiling point | 478 °C (892 °F; 751 K) |
Solubility in water
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0.57 g/100 mL (25 °C) 4.0 g/100 mL (75 °C) |
Solubility | soluble in alcohol, pyridine, NaOH insoluble in ethyl ether |
log P | -3.14 |
Acidity (pKa) | 8.48 |
Hazards | |
Safety data sheet | Allantoin MSDS |
NFPA 704 |
1
2
0
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Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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> 5000 mg/kg (oral, rat) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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N verify (what is YN ?) | |
Infobox references | |
Allantoin is a chemical compound with formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide.[1][2] It is a diureide of glyoxylic acid.
Allantoin was first isolated in 1800 by the Italian physician Michele Francesco Buniva (1761–1834) and the French chemist Louis Nicolas Vauquelin, who mistakenly believed it to be present in the amniotic fluid.[3] In 1821, the French chemist Jean Louis Lassaigne found it in the fluid of the allantois; he called it "l'acide allantoique".[4] In 1837, the German chemists Friedrich Wöhler and Justus Liebig synthesized it from uric acid and renamed it "allantoïn".[5]
Named after the allantois (an amniote embryonic excretory organ in which it concentrates during development in most mammals except humans and higher apes[vague]), 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.[6] 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.[7] Allantoin is a major metabolic intermediate in many other organisms including plants and bacteria.
Allantoin has been shown to improve insulin resistance when administered to rats and increased lifespan when administered to the nematode worm C.elegans [8] [9]
Allantoin is present in botanical extracts of the comfrey plant and in the urine of most mammals. Chemically synthesized bulk allantoin, which is chemically equivalent to natural allantoin, is safe, non-toxic, compatible with cosmetic raw materials and meets CTFA and JSCI requirements. Over 10,000 patents reference allantoin.[10]
Manufacturers cite several beneficial effects for allantoin as an active ingredient in over-the-counter cosmetics, including: 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; promoting cell proliferation and wound healing; and a soothing, anti-irritant, and skin protectant effect by forming complexes with irritant and sensitizing agents.
A animal study in 2010 found that based on the results from histological analyses, a soft lotion with 5% allantoin ameliorates the wound healing process, by modulating the inflammatory response. The study also suggests that quantitative analysis lends support to the idea that allantoin also promotes fibroblast proliferation and synthesis of the extracellular matrix. [11]
A study published in 2009 reported the treatment of pruritus in mild-to-moderate atopic dermatitis with a topical non-steroidal agent containing allantoin.[12]
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.[13]
Since uric acid is the end product of the purine metabolism in humans, only non-enzymatic processes with reactive oxygen species will give rise to allantoin, which is thus a suitable biomarker to measure oxidative stress in chronic illnesses and senescence.[14][15]
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リンク元 | 「アラントイン」 |
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