Фолиевая кислота

Описание

Folic acid is an essential B vitamin. It is converted to folate in vivo, which is a necessary cofactor for a variety of biological processes, including nucleotide synthesis and, thus, DNA synthesis and repair, among others. A deficiency in dietary folic acid can lead to a range of developmental and cognitive disorders, most prominently neural tube defects and congenital heart defects.

Химические свойства

orange to yellow crystalline powder

Физические свойства

The folates include a large number of chemically related species, each differing with respect to the various substituents possible at three sites on the pteroylglutamic acid basic structure. More than 170 different folates are theoretically possible. Not all of these occur in nature; but it has been estimated that as many as 100 different forms are found in animals. The folates from most natural sources usually have a single carbon unit at N-5 and/or N-10; these forms participate in the metabolism of the single-carbon pool.
Folic acid (pteroylmonoglutamic acid) is an orange-yellow crystalline substance that is soluble in water but insoluble in ethanol or less polar organic solvents. It is unstable to light, to acidic or alkaline conditions, to reducing agents, and, except in dry form, to heat. It is reduced in vivo enzymatically (or in vitro with a reductant such as dithionite) first to 7,8-dihydrofolic acid (FH2) and then to FH4; both of these compounds are unstable in aerobic environments and must be protected by the pres ence of an antioxidant (e.g., ascorbic acid, 2-mer
Two derivatives of folic acid, each having an amino group in the place of the hydroxyl at C-4, are folate antagonists of biomedical use: aminopterin (4-aminofolic acid) and methotrexate (4-amino-N10-methylfolic acid). Aminopterin is used as a rodenticide; methotrexate is an antineoplastic agent.

Вхождение

Synthetic

Использование

folic acid is generally used as an emollient. In vitro and in vivo skin studies now indicate its capacity to aid in DnA synthesis and repair, promote cellular turnover, reduce wrinkles, and promote skin firmness. There is some indication that folic acid may also protect DnA from uV-induced damage. Folic acid is a member of the vitamin B complex and is naturally occurring in leafy greens.

Определение

ChEBI: An N-acyl-amino acid that is a form of the water-soluble vitamin B9. Its biologically active forms (tetrahydrofolate and others) are essential for nucleotide biosynthesis and homocysteine remethylation.

Общее описание

Odorless orange-yellow needles or platelets. Darkens and chars from approximately 482°F.

Реакции воздуха и воды

Insoluble in water. Aqueous solutions have pHs of 4.0-4.8.

Профиль реактивности

Acid solutions of Folic acid are sensitive to heat, but towards neutrality, stability progressively increases. Solutions are inactivated by ultraviolet light and alkaline solutions are sensitive to oxidation. Folic acid is also inactivated by light. Folic acid is incompatible with oxidizing agents, reducing agents and heavy metal ions.

Пожароопасность

Flash point data for Folic acid are not available; however, Folic acid is probably combustible.

Профиль безопасности

Poison by intraperitoneal and intravenous routes. Experimental teratogenic effects. Mutation data reported. When heated to decomposition it emits toxic fumes of NOx.

Методы очистки

If paper chromatography indicates impurities, then recrystallise it from hot H2O or from dilute acid [Walker et al. J Am Chem Soc 70 19 1948]. Impurities may be removed by repeated extraction with n-BuOH of a neutral aqueous solution of folic acid (by suspending in H2O and adding N NaOH dropwise till the solid dissolves, then adjusting the pH to ~7.0-7.5) followed by precipitation with acid, filtration, or better collected by centrifugation and recrystallised form hot H2O. [Blakley Biochem J 65 331 1975, Kalifa et al. Helv Chim Acta 6 1 2739 1978.] Chromatography on cellulose followed by filtration through charcoal has also been used to obtain pure acid. [Sakami & Knowles Science 129 274 1959.] UV: max 247 and 296nm ( 12,800 and 18,700) in H2O pH 1.0; 282 and 346nm ( 27.600 and 7,200) in H2O pH 7.0; 256, 284 and 366nm ( 24600, 24,500 and 86,00) in H2O pH 13 [Rabinowitz in The Enzymes (Boyer et al. Eds), 2 185 1960]. [Beilstein 26 III/IV 3944.]