Allantoin,CAS 97-59-6

Allantoin is a skin conditioning agent that promotes healthy skin, stimulates new and healthy tissue growth.
DryPowder|Solid
Allantoin is an imidazolidine-2,4-dione that is 5-aminohydantoin in which a carbamoyl group is attached to the exocyclic nitrogen. It has a role as a vulnerary, a human metabolite, a Saccharomyces cerevisiae metabolite and an Escherichia coli metabolite. It is a member of ureas and an imidazolidine-2,4-dione. It derives from a hydantoin. It is a tautomer of a 1-(5-hydroxy-2-oxo-2,3-dihydroimidazol-4-yl)urea.|Allantoin is a substance that is endogenous to the human body and also found as a normal component of human diets. In healthy human volunteers, the mean plasma concentration of allantoin is about 2-3 mg/l. During exercise, the plasma allantoin concentration rapidly increases about two fold and remains elevated. In human muscle, urate is oxidized to allantoin during such exercise. The concentration of allantoin in muscles increases from a resting value of about 5000 ug/kg to about 16000 ug/kg immediately after short-term exhaustive cycling exercise. More specifically, allantoin is a diureide of glyoxylic acid that is produced from uric acid. It is a major metabolic intermediate in most organisms. Allantoin is found in OTC cosmetic products and other commercial products such as oral hygiene products, in shampoos, lipsticks, anti-acne products, sun care products, and clarifying lotions. Allantoin has also demonstrated to ameliorate the wound healing process in some studies.|A urea hydantoin that is found in URINE and PLANTS and is used in dermatological preparations.

Allantoin Use and Manufacturing
Methods of Manufacturing
Allantoin is present in sac fluid, fetal urine and some plants. But the cost of extracting cystin from these substances is too high. The current methods of synthesizing allantoin are: potassium permanganate oxidation of urea acid method: the synthesis of allantoin by the heating of dichloroacetic acid and urea; the direct condensation method of glyoxylic acid and urea. 1. The process of using dichloroacetic acid and urea as raw materials is as follows: put sodium methoxide solution and methanol in the reaction tank, heat to 40-50℃, slowly add dichloroacetic acid dropwise, and then reflux for 2h after the addition. Cool to room temperature, filter, wash with methanol, wash the combined filtrate, and run sodium dimethoxylate in methanol. The solution was reduced to dryness under reduced pressure, 2.8 parts of hydrochloric acid was added, heated on a water bath and stirred into a paste. Then raise the temperature to 90 ℃, then cool to about 10 ℃, filter, add 0.25 parts of hydrochloric acid and urea to the small liquid, heat to dissolve, and react at 80 ℃ for 2h. Cool and crystallize, and then maintain at 0 ℃ for more than 3h, centrifuge, wash with water, spin dry, and dry to get fine products. Allantoin was obtained after the crude product was recrystallized with 15 times water. The total yield of p-dichloroacetic acid is 30.3%. 2. Direct condensation of glyoxylic acid and urea (glyoxylic acid is obtained by oxidation of glyoxal) Operation example: (1) Oxidation in a 500ml four-necked bottle equipped with mechanical stirring, condenser, thermometer and dropping funnel, Add 193g (1mol) 30% glyoxal aqueous solution, add 135.5g (1mol) 45% nitric acid dropwise with stirring while controlling the internal temperature at 40±2℃, continue to stir the reaction at this temperature for 2-3h after the addition, until the red brown oxidation is no longer After escaping, the reaction solution is blue-green and disappears. Replaced with a simple distillation device, about 125g of water is distilled off at about 2.76kPa, and the external temperature does not exceed 60°C. The concentrated liquid is still at room temperature overnight, and the precipitated oxalic acid crystals (19g after drying, 0.21mol), the concentration is 39% ). Continue to stir the reaction at an internal temperature of 40±2°C for about 8 hours, and the oxidation reaction is completed. (2) Condensation In a 500ml three-necked flask equipped with a mechanical stirrer, condenser and thermometer, add the above 150g glyoxylic acid aqueous solution, then add 170g (2.83mol) urea and 23.3g concentrated hydrochloric acid, and heat to an internal temperature of 80 with stirring ℃. After about 15 minutes, the urea dissolves and the reactant is a transparent liquid. After about 30-45 minutes, the reactant becomes cloudy, and then the white precipitate gradually increases. Stir at the internal temperature of 80 ℃ for 1 hour, stop heating and cool the reactant to room temperature. Collect the white precipitate with a Buchner funnel and precipitate it in cold water several times to obtain crude allantoin. Recrystallize with 1000ml of distilled water. Obtained white fine crystal allantoin 60-63%, melting point 236 ℃ (decomposition). Based on glyoxal, the allantoin yield is theoretically 38-40% (weight yield 103-108%).
Uses
Used in skin care, oral products, anti-allergic, treatment of skin ulcers and promote wound healing; widely used in the treatment of various skin ulcers and wounds and additives in nutritional cosmetics; as an effective biomarker for oxidative stress; used in synthesis Mannich base as an antibacterial agent; used in the synthesis of sulfonamide analogs as an antitumor agent; used as a plant growth regulato