Folacin

Therapeutic Function Treatment of B vitamin (folacin) deficiency... 

Folic Acid (Folacin Pteroylglutamic Acid Folate)... 

Parenteral 300 meg vials and prefilled syringes for IV or SC injection Folic acid (folacin, pteroylglutamic acid) (generic)... 

Much of the folacin in food is present as conjugated pteroyl polyglutamates. Soybean contains 40% monoglutamate analogues, but in cabbage 90% of folic acid is present in forms... 

Bailey. L.B. cl al. Folacin and Iron Status and Hematological Findings in Black and Spanish American Adolescents. On Geriatr. Sot,. 27, 444 1I982i. 

Chen, T.S.. R.G, Cooper "Thermal Destruction of Folacin Effect of Ascorbic Acid. 

Food yeast, molasses-grown, is dried to about 5% moisture and has the same chemical composition as bakers yeast. In terms of micrograms per gram of yeast, the vitamin content is 165 thiamine 100 riboflavin 590 niacin 20 pyridoxine 13 folacin 100 pantothenic acid 0.6 biotin 160 para-ainiiiobeuzoie acid 2710 choline and 3000 inositol. YeasL crude protein contains 80% amino acids 12% nucleic acids and 8% ammonia. The latter components lower the true protein content to 40% of the dry cell weight. 

Folacin occurs in a wide variety of foods, including green leafy vegetables, liver, yeast, beans, dairy products, and eggs (120,121). 

Folacin bioavailability varies among the vitamers (120,125). Folic acid is more readily available than the naturally occurring food folates but may be less available from fortified foods than in aqueous solution or tablet form. Food folates have been reported to be 30-80% as available as folic acid. Folacin availability, absorption, and metabolism were recently reviewed (20,120,122). 

Biochemically, folacin functions in vivo as coenzymes and carriers of one-carbon units for a number of enzyme reactions, including synthesis of amino acids, proteins, and nucleic acids (58,120,122). Folacin participates in both anabolic and catabolic reactions, and its metabolism is cyclic in nature. Greater detail on the biochemistry of folacin is available (120,122). 

Folacin deficiency produces a megaloblastic anaemia not unlike that produced by vitamin B12 deficiency (120,122,126-130). This is a result of the interdependence of folacin and vitamin B,2 in at least two biochemical pathways in vivo. Folacin deficiency also appears to affect neurological function. 

Folacin has recently been implicated in a number of nonvitamin functions, including roles in various types of cancer, coronary heart disease, and the prevention of birth defects, such as neural tube abnormalities (109,121,131-144). Investigations into these functions are ongoing and have generated controversy concerning the exact nature of the nonvitamin functions, human nutritional requirements for folacin, and the wisdom of food fortification or supplementation of selected population groups with pharmacological doses of folic acid (131,132,145-150). 

Folacin extraction from foods generally begins with homogenization in neutral or mildly acidic solution (122-124,152,153). One study (152) demonstrated that an extraction at pH 7.85 provided the most efficient recovery of endogenous folate from plant and animal tissues a second extraction of the residual tissue significantly increased the completeness of the extraction procedure. The extractant should contain antioxidants, such as ascorbic acid, 2-mercaptoethanol, dithiothreitol, or a mixture thereof to protect the natural oxidation states of the folacin vitamers. 

It should be noted that ascorbic acid is more stable at pH 4-5 than at pH 7, at which the folacin vitamers are more stable. Additional protection from oxidation can be achieved by degassing the extraction solution with an inert gas, such as helium. Homogenization is followed immediately by protein precipitation and release of bound folacin vitamers. This can be accomplished by mild acidification, heating, addition of organic compounds such as trichloroacetic acid, and/or enzymatic (e.g., papain) hydrolysis. The specific conditions used for homogenization and protein precipitation are dictated by the food matrix and the expected profile of folacin vitamers. 

Three recent reviews included HPLC methods for food folacin. Mullin and Duch (122) reviewed selected HPLC methods for determining the folacin vitamers in foods, biological tissues, and pharmaceuticals. They also included paper chromatography, TLC, and microbiological methods. Russell (44) reviewed selected HPLC methods published between 1990 and 1994 for folacin quantitation in foods, including a brief review of the reference methods. Ball (45) reviewed HPLC and microbiological methods for the quantitation of folacin in food samples. 

Tables 18-20 summarize HPLC methods, published from 1992 to 1997, for folacin quantitation in foods. The simultaneous quantitation of folacin with one or more other vitamins is covered later in this chapter in Sec. XI.

Table 18 HPLC Methods for Quantitating Total Folacin in Foods (Cg/C, 8 Columns UV Absorbance Detection)... 

Total Folacin Unfortified Extraction with boil- Analytical ... 

Total folacin Egg yolk lima Extraction with Analytical A aqueous solution UV absorbance External standardization. 

Table 20 HPLC Methods for Quantitating Folacin Vitamers in Foods (Clg Columns Fluorescence and UV Absorbance and Fluorescence Detection)... 

H4PteGlu, sausage liver atmosphere with Pak (4 X B acetonitrile (ex/em) for folacin vitamers. ... 

A deficiency of vitamin B12 produces pernicious anemia similar to that from folacin deficiency. This is due to the interdependence of vitamin Bl2 and folacin in at least two biochemical pathways (126-128,130,167,168). Neuropsychiatric abnormalities have also been reported in conjunction with vitamin B,2 deficiency. Vitamin B,2 has also been implicated in certain nonvitamin functions, including coronary heart disease and neural tube defects (109,133,134,170). 

Russell (44) and Ball (45) summarized multivitamin methods for foods that determined various combinations of thiamine, riboflavin, niacin, vitamin B6, folacin, and biotin. 

Table 27 HPLC Methods for Quantitating Riboflavin, Niacin, Pyridoxine, and Folacin in Food... 

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