Tetrahydrofolic acid

Химические свойства

Light Tan Solid

Использование

Asa folic acid derivative and coenzyme, L-Tetrahydrofolic Acid can be involved in the metabolism of amino and nucleic acids.

Определение

ChEBI: A derivative of folic acid in which the pteridine ring is fully reduced; it is the parent compound of a variety of coenzymes that serve as carriers of one-carbon groups in metabolic reactions.

Методы очистки

Very high quality material is now available commercially, and it should be a white powder. It can be dried over P2O5 in a vacuum desiccator and stored in weighed aliquots in sealed ampoules. It is stable at room temperature in sealed ampoules for many months and for much more extended periods at -10o. When moist, it is extremely sensitive to air whereby it oxidises to the yellow 7,8-dihydro derivative. In solution it turns yellow in colour as it oxidises, and then particularly in the presence of acids it turns dark reddish brown in colour. Hence aqueous solutions should be frozen immediately when not in use. It is always advisable to add 2-mercaptoethanol (if it does not interfere with the procedure for which it is used) which stabilises it by depleting the solution of O2. The sulfate salt is more stable but is much less soluble. The best way to prepare standard solutions of this acid is to dissolve it in the desired buffer and estimate the concentration by UV absorption in pH 7 buffer at 297nm ( 22,000 M-1cm-1). If a sample is suspect, it is not advisable to purify it because it is likely to deteriorate further as “dry box” conditions are necessary. Either a new sample is purchased or one is freshly prepared from folic acid. It has the above pKa values. [Hafeti et al. Biochemical Preparations 7 89 1960, UV: Mathews & Huennekens J Biol Chem 235 3304 1960, Osborn & Huennekens J Biol Chem 233 969 1958, O'Dell et al. J Am Chem Soc 69 250 1947, Blakley Biochem J 6 5 331 1957, Asahi Yakugaku Zasshi (J Pharm Soc Jpn) 79 1548 1959, Beilstein 26 III/IV 3879.]