Liebermann–Burchard reaction The intensity of colour is proportional to the concentration of cholesterol. This reaction is used for the quantitative determination of cholesterol in blood.

The chemical properties are related to the secondary hydroxyl group and the double bond at C5 – C6. Cholesterol, when oxidised in suitable conditions, undergoes rapid oxidation to corresponding ketone and cholestenone. The hydroxyl group readily forms esters with acids. The fatty acid esters, namely cholesterol acetate palmitate and propionate, are found in blood and tissues.…

Physical properties They are white shining rhombic plate like crystals. They are tasteless and odourless. Cholesterol has a high melting point of 150°C. Cholesterol is insoluble in water and soluble in fat solvents (chloroform, acetone, and benzene). It is soluble in soap solution and bile salt solution. When mixed with fat or oil, cholesterol has…

The molecular formula of cholesterol is C27 H45 OH. It is monounsaturated tetracyclic alcohol. The structure of cholesterol, as proposed by Windaus, has the following characteristic features:

Cholesterol is widely distributed in all the cells of the body. It occurs in large quantities in brain and nerve tissues. It is found in adrenal glands, glandular tissues, plasma, and egg yolk. It may be noted that cholesterol occurs in animal fats and not in plant fats.

Cholesterol means solid bile alcohol. It derives its name from the Greek word cholesterine (chole – bile, sterine – solid).

STEROLS Sterols means solid alcohol. They are widely distributed in animal and plant tissues. They include cholesterol, 7-dehydrocholesterol, ergosterol, calciferol, and coprosterol. Among the sterols, cholesterol forms an important physiological compound.

Male: C19 – androgen, testosterone, androsterone Female: C18 – estradiol, estriol, estrone, progesterone.

Mineralocorticoids C21– aldosterone, deoxycorticosterone, glucocorticoids – cortisone, cortisol, corticosterone