In the Chemistry of the Vitamins
prevents dermatitis in chicks and growth failure in rats, but its therapeutic role in human nutrition is still unknown. Pantothenic acid is usually isolated asits calcium salt, m.p. 198°-200DC.
\/
CHI
Vitamin A
v
ITAMIN A is recognized as an essential factor in the maintenance of the integrity of the epithelial tissues. Deficiency results in abnormal keratinizatiou of tissues, xerophthalmia, night blindness, and other disturbances. Three naturally occurring carotenes are precursors of vitamin A, the beta-carotene yielding two equivalents of vitamin A. B y use of molecular stills, concentrates of vitamin A are now being prepared commercially by fractional vacuum distillation.
C.CH3.0H Vitamin B8Hydrochloride (Pyridoxine) Pyridoxine, another factor of the vitamin BBcomplex, has been established as of some im~ortancein nutrition. ~articularlvin deficiency diseases. It is sparingly soluble in acetone, but is soluble in both alcohol and water.
..
CHI N-C.NHa+-CI
I
CHI,C
I
I
C--C.CH..CH..OH
C. CHQ.(Cl-)+N
I 1 HO OH Vitamin C (Ascorbic acid)
H . C S Vitamin B, (Thiamin hydrochloride) Vitamin B, appears t o be essential for the normal functioning of the nervous system and the gastra-intestinal tract. I t is used in the treatment of beriberi, and acts as an appetite stimulant. I t is now being produced synthetically. It is soluble in alcohol and water. CHn.HOCH. HOCH. HOCHCHn.OH I
Vitamin C is used as a prophylaxis and in the treatment of scurvy. I t appears to be essential to the maintenance of sound bones and teeth, and aids in bodily resistance t o toxins and infections. I t is produced synthetically from either sorbose or xylose. I n the formulation shown here, the group t o the right of an asymmetric grouping is believed t o be below the plane of the page, whereas the group to the left is above the plane of the page, with all other groups in the plane of the page.
Vitamin BnComplex (Riboflavin)
1
Riboflavin is a part of the vitamin B* complex, and is thought t o be essential t o the normal functioning of the motor, sensory, and central nervous systems. I t is slightly soluble in water, sparingly soluble in phenol, amyl acetate, and cyclohexanal, but insoluble in acetone, benzene, chloroform, and ether.
Hr
Hz
H Vitamin D* (Calciferol)
\4 C.H Nicotinic acid, m.p. 235'-7'C. Nicotinamide, m.p. 1299-31PC. Vitamin B1Complex (Nicotinic acid and Nicotinamide) Nicotinic acid and nicotinamide both show activity similar t o vitamin BZcomplex, and serve as a prophylaxis against pellagra. Certain individuals respond t o treatment with nicotinic acid by flushing of the face, itching, and burning of the skin, whereas nicotinamide does not produce these undesirable disturbances and appears t o be just as effective otherwise.
H0.CHz.(CH1)2C.CHOH.C0.NH.CH2.CH1. C02H Vitamin BI Complex (Pantothenic acid) Pantothenic acid has been known as the jiltrate factor of vitamin B2complex. Experimental studies have demonstrated that it
Vitamin DZis formed following irradiation of ergost'erol, 7dehydrocholerterol, and other sterols. It is available commercially as wioslerol, but is not produced synthetically. It is stable t o acids, alkalies, heat, and oxidation. I t is soluble in fats and oils, but insoluble in water. ~h~ "itamin D or anti-rachitic group may include as many as twelve or more dieerent substances which exert anti-rachitic oneof the more important ones is believed t o be DI which is formed in human and animal bodies when the skin is exposed directly t o sunlight or ultra-violet light. The D group is essential to normal bone growth and tooth development, since these factors aid in controlling the calcium level of the blood and the metabolism of both lime and phosphorus. (Confinued on page 448.)
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