• Folic acid (also known as folate, vitaminM, vitamin B9(or folacin), pteroyl-L-glutamic acid, pteroyl-L-glutamate,• and pteroylmonoglutamic acid are formsof the water-soluble vitamin B9.
• Folic acid is itself not biologically active,but its• biological importance is due totetrahydrofolate and other derivatives afterits conversion to dihydrofolic acid in theliver
• Folate and folic acid derive their namesfrom the Latin word folium (which means"leaf"). Leafy vegetables are principalsources of folic acid,
6it is also known as folacin or folate.it is water soluble vitamin .it is yellow crystalline substance.
• Chemically it consists of pteridine, para-aminobenzoic acid, and glutamate (Pte-GLU). Additional glutamate groups maybe added via the γ-carboxylate group,resulting in polyglutamates (PteGLUn).Folic acid can occur in the reduced or theoxidized form,
Sources• Certain foods are very high in folate:• Leafy vegetables such as spinach,asparagus, turnip greens, lettuce andsome Asian vegetables[• Legumes such as dried or fresh beans,peas and lentils• Egg yolk
• Bakers yeast• Fortified grain products (pasta, cereal, bread);some breakfast cereals (ready-to-eat andothers) are fortified with folate• Sunflower seeds• Liver and liver products contain high amounts offolate• Kidney
17Absorption & excretionIt is readily absorbed in the jejunum & ileumof small intestine .storage – liver.Excretion –through feces and urine
COENZYME FORMS OF FOLIC ACID:1. Tetrahydrofolic acid, FH4:2. Folinic acid:3. Rhizopterin:
METABOLIC ROLE(ONE CARBON METABOLISM):FH4 is the coenzyme form of folic acid and itacts as coenzyme in transfer and utilizationof one carbon moiety [C1]One Carbon Donor and Acceptor Compounds:
One carbon donor group One carbon acceptor groupFormimino group offormimino glu [from his].N-formyl methionine oftransfer-RNA.Methyl group of methionine. Glycine to form serine.Methyl group of methionine. Glycine to form serine.Methyl group of thymine. Uracil to form thymine.β-carbon of serine. Ethanolamine to form choline.Gly, trp, ALA and acetone, Positions 2 and 8 of purinering.Histidine synthesis.
FOLATE ANTAGONISTS:1. SULFONAMIDES2. TRIMETHOPRIM:3. PYRIMETHAMINE:4. AMINOPTERIN AND AMETHOPTERIN:5. Methotraxate
• Antifolates• Folate is important for cells and tissuesthat rapidly divide Cancer cells dividerapidly, and drugs that interfere with folatemetabolism are used to treat cancer.
It is especially important in aiding rapidcell division and growth, such as in infancyand pregnancy. Children and adults bothrequire folic acid to produce healthy redblood cells and prevent anemia
• Folate is a coenzyme for single carbontransfers (addition or subtraction of asingle carbon molecule). This is critical forDNA metabolism. A folate coenzyme isnecessary to synthesize nucleotides fromtheir components, in order to make DNAas well as RNA.
• A folate coenzyme is also necessary forthe synthesis of the amino acidmethionine. Methionine is part of the chainof reactions leading to the production of S-adenosylmethionine (SAMe;( SAMe is amethyl donor).
• Folate is therefore necessary for reactionsthat involve methylation,many of which arecritical to cell function and survival.
• Deficiency can result in many healthproblems, the most notable one beingneural tube defects in developingembryos.
• Common symptoms of folate deficiencyinclude diarrhea, macrocytic anemia withweakness or shortness of breath, nervedamage with weakness and limb numbness(peripheral neuropathypregnancycomplications, mental confusion,
forgetfulness or other cognitive declines,mental depression, sore or swollentongue, peptic or mouth ulcers,headaches, heart palpitations, irritability,and behavioral disorders. Low levels offolate can also lead to homocysteineaccumulation
• DNA synthesis and repair are impairedand this could lead to cancer development
31Daily requirementMen – women – 100 mcgChildren – 80 mcg.Infant – 25 mcgpregnant women – 400mcg
32DEFICIENCYAnemia – often occurs in pregnant women andalso childrenskin – loss of hair, grayish brown skinpigmentation can also occur.Nervous – mental depression & fatigue.ORAL- severe ulcerative stomatitis may be seen.swelling & redness of lips.
Hair & Skin – it is essential for the health ofskin & hairPregnancy – it is an important nutrient for thepregnant women & her developing fetus.&folic acid improves the lactation.
Folic Acid DeficiencyDeficiency causes:• Sensations ofweakness• Numbness andtingling of fingers andtoes• Ulcers in the mouth• Sore tonguesFeelings of weakness:
37FUNCTIONSFormation of RBC – folic acid incombination with vitamin B12 is essential forformation, and maturation of RBCs
DEFICIENCY:It is the most common vitamin deficiency observed primarily inpregnant women, lactating mother , women on OCPs and alcoholics.In pregnancy decreased absorption and increased clearance is thecause. Anaemia: macrocytic typeFIGLU test - to detect folate deficiency.
FUNCTIONS:The active form of folic acid isTetrahydrofolate.It acts as coenzymes invarious bio-chemical reactions.
45BIOCHEMISTRY PEARLS• Folate (folic acid) is an essentialvitamin that, in its active form oftetrahydrofolate, transfers 1-carbongroups to intermediates in metabolismand plays an important role in DNAsynthesis.
• THF is necessary for the de novosynthesis of purines and the conversion ofdeoxyuridine 5’-monophosphate (dUMP)to deoxythymidine 5’-monophosphate(dTMP).• The major metabolic perturbation in folatedeficiency occurs in megaloblasticanemia.