Biochemistry

сн 3 он о I I к OH-CH 2 ” C - ch - c - nh - ch 2 - ch 2 - cooh Butyric acid residue Remainder of p-alanme Pantothenic acid is a viscous liquid, highly soluble in water, worse soluble in ether and alcohol. It is unstable to high temperatures and is destroyed by sterilization and cooking. Acidic and alkaline environments contribute the destruction of pantothenic acid. Biological role. Vitamin B 3 is an integral part of many enzymes. It is part of coenzyme A, which provides the biosynthesis and oxidation of fatty acids; decarboxylation of pyruvic and a-ketoglutaric acids is carried out with the participation of CoA. Pantothenic acid is involved in the conversion of proteins (amino acids become keto acids after deamination); in the synthesis of hemoglobin; has a regulatory effect on the nervous system functions; helps neutralize industrial poisons. Deficiency B3. Lack of pantothenic acid in the body is manifested by lethargy, drowsiness, apathy, pain in the legs, a decrease in resistance to infections, intoxications. It can occur with insufficient protein in the diet for a long time. Alimentary deficiency of pantothenic acid intensifies intestinal diseases, accompanied by dysbiosis. In this case, endogenous synthesis of pantothenic acid is sharply reduced and its assimilation is disturbed. Long-term use of antibiotics and sulfonamides leads to hypovitaminosis. Daily intake of vitamin B 3 for adults is 5-10 mg. It increases with hard physical labor, in pregnant and lactating women, with increased thyroid function, insufficient protein in the diet. Sources. Pantothenic acid is rich in animal liver, egg yolk, meat, legumes, and cauliflower. Dairy products, fruits and some vegetables are not rich for vitamin B 3 . Part of vitamin B 3 is synthesized by the microflora of the colon. Folic acid (folacin, pteroylglutamic acid, vitamin B c ). The first information of this substance was received in 1940 after experiments on chickens (hence the index "c" - from English chicken). A year later, folic acid was isolated from the green leaves of plants, and therefore got its name (from lat. follium - leaf). In 1945 it was installed identity of vitamin B c with folic acid obtained from the spinach leaves and synthetically. Structure and physicochemical properties. Folic acid consists of three structural units: pteridine residue (I), para-aminobenzoic acid (II) and glutamic acid (III). 256